EPA-660/2-74-006 A p r i l 1974
WASTEWATER ABATEMENT IN CANNING VEGETABLES
BY IQB BLANCHING
Daryl B. Lund U n i v e r s i t y of Wisconsin
Madi son Wisconsin
Grant No. S-801484 Program E l ement 1 BB037
P r o j e c t O f f i c e r
M r . Haro ld Thompson P a c i f i c Northwest Environmental Research Laboratory
Corval1 i s Oregon 97330
Prepared f o r OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D. C. 20460
For sale by the Superintendent of Documents, U.S. Governmeiit Printing Office, Washington, D.C. 20402 -Price $1.25
ABSTRACT
This r e p o r t p re sen t s t he r e s u l t s of a s tudy on t h e e f f i c a c y of a new blanching system, Indiv idua l Quick Blanch (IQB), a s appl ied t o vege tab les p r i o r t o canning. Peas, corn, l i m a beans, green beans, po ta toes , c a r r o t s and b e e t s were adequately blanched by I Q B . Compared t o deep bed steam blanching o r p ipe blanching, IQB gene ra l ly r e s u l t e d i n a s i g n i f i c a n t reduct ion i n e f f l u e n t . S l i g h t drying of the vege tab les before I Q B reduced e f f l u e n t even more; how- ever , product q u a l i t y w a s adversely a f f e c t e d i n most cases . s t r a t e d t h a t t h e I Q B process can s i g n i f i c a n t l y reduce e f f l u e n t volume and BOD genera t ion i n the blanching opera t ion whi le adequately f u l f i l l i n g the objec- t i v e s of blanching. Commercial app l i ca t ion of I Q B appears economically favorable .
I t was demon-
This r epor t was submitted i n f u l f i l l m e n t of P r o j e c t Number S-801484, by Daryl Lund, Univers i ty of Wisconsin, under the p a r t i a l sponsorship of the Environmental P ro tec t ion Agency. Work w a s completed as of August 1973.
ii
CONTENTS
Abstract
List of Tables
Acknowledgments
Sect ions
I
I1
I I1
IV
V
VI
VI1
VI11
IX
X
Conclusions
Recommendat ions
Introduction
Objectives
Materials and Methods
Results and Discussion
Units for Interconversion of Data
References
List of Publications
Append ix--Raw Data
Page
ii
j,V
vi
1
2
3
7
8
18
56
58
60
61
iii
TABLES
No.
1
2
3
4
5
-
6
7
8
9
10
11
12
13
14
15
1 6
17
18
19
20
2 1
Product Forms and P rocess ing Dates
Blanching Methods
Blanching Times and Temperatures
Product Eva lua t ion Tests
Hourly Make-up Water Flow Ra tes and T o t a l S o l i d s Content of P i p e Blancher Water f o r P e a s , Corn, L i m a Beans and Green Beans
Summary of Pea Blanching Data
Summary of O b j e c t i v e Eva lua t ion of Peas
Sumnary o f S u b j e c t i v e E v a l u a t i o n of Peas
Summary of Corn Blanching Data
Summary of O b j e c t i v e Eva lua t ion of Corn
Sumnary of S u b j e c t i v e Eva lua t ion of Corn
Summary of Lima Bean Blanching Data
Summary of O b j e c t i v e Eva lua t ion of Lima Beans
Summary of S u b j e c t i v e E v a l u a t i o n of L ima Beans
Summary of Green Bean Blanching Data
Summary of O b j e c t i v e Eva lua t ion of Green Beans
Sunnnary of S u b j e c t i v e Eva lua t ion of Green Beans
Summary of P o t a t o Blanching Data
Summary of O b j e c t i v e E v a l u a t i o n of P o t a t o e s
Summary of S u b j e c t i v e E v a l u a t i o n of P o t a t o e s
Sumnary of Beet Blanching Data
Page
9
10
15
20
23
27
29
30
31
33
34
36
37
38
41
42
42
44
45
46
i v
TABLES
No.
22
23
-
2 4
25
26
27
2 8
2 9
Summary of Objective Evaluation of Beets
Summary of Subjective Evaluation of Beets
Summary of Carrot Blanching Data
Summary of Objective Evaluation of Carrots
Summary of Subjective Evaluation of Carrots
Estimated IQB Production Units
Factors for Interconversion of Data
Canning Yield Factors
Page
49
5 0
5 1
52
5 2
56
5 7
5 8
V
ACKNOWLEDGMENTS
The cooperation and support of this p r o j e c t by t h e Oconomowoc Canning Company,
Oconomowoc, Wisconsin, i s acknowledged with s i n c e r e thanks. Personnel a t t h e
Sun P r a i r i e and Waunakee P lan t s provided va luab le a s s i s t a n c e .
Pa r t i a l f i n a n c i a l support w a s provided by the Widconsin Canners and Freezers
Association and t h e i r con t r ibu t ion i s g r a t e f u l l y acknowledged.
The IQB blanching u n i t was suppl ied by t h e Western Regional Research Labora-
t o r y , USDA , Berkeley, Ca l i fo rn ia . Obviously, without t h e i r support t h i s
p r o j e c t would n o t have been poss ib l e .
Thanks i s a l s o extended t o the Hughes Company, Columbus, Wisconsin, f o r
supplying some of t he equipment required i n th i s p ro jec t .
A special thanks i s extended t o t h e Water Qua l i ty Laboratory, Wisconsin S t a t e
Department of Natural Resources, Madison. This l abora to ry performed most of
t he water q u a l i t y tes ts and thus provided t h e bulk of t h e r a w d a t a i n t h i s
r e p o r t .
F i n a l l y , acknowledgment i s extended t o personnel i n the Department of Food
Science who contr ibuted t o the success fu l completion of t h i s p r o j e c t . Special
thanks goes t o the personnel of t he Sensory Evaluation Laboratory and t h e
tas te panel members.
v i
SECTION I
CONCLUSIONS
Conventional blanching opera t ions r e s u l t i n the genera t ion of h igh volume,
h igh s t r e n g t h waste streams.
v idua l Quick Blanching, was assessed w i t h the o b j e c t i v e of s i g n i f i c a n t l y re-
ducing blanching e f f l u e n t while main ta in ing product q u a l i t y .
t o peas , corn , l i m a beans, green beans, po ta toes , b e e t s and c a r r o t s p r i o r t o
canning.
The e f f i c a c y of a new blanching system, Indi -
__--- I_-. - -. --- IQB w a s appl ied
--
I Q B was found s u i t a b l e f o r blanching vegetab les p r i o r t o canning. E f f luen t
genera t ion w a s s i g n i f i c a n t l y reduced f o r peas , corn , lima beans and green
beans compared t o p ipe blanching and deep bed steam blanching. Product q u a l i t y
t e s t s ind ica ted tha t IQB blanched, canned products were as good as pipe
blanched, canned products. For pota toes , b e e t s and c a r r o t s , I Q B could be
e f f e c t i v e l y used t o i n a c t i v a t e peroxidase whi le minimizing inequ i ty of heat
t reatment received by the su r face and c e n t e r of the product.
S l i g h t dry ing of the product p r i o r t o IQB f u r t h e r reduced blancher e f f l u e n t s .
However, gene ra l ly canned product q u a l i t y w a s adverse ly a f f e c t e d by t h i s pre-
t reatment .
1
SECTION I1
RE COMME NDA T IONS
This s tudy w a s l imi ted t o a p i l o t p l a n t eva lua t ion of the ind iv idua l quick
blanching (IQB) system. It success fu l ly demonstrated the p o t e n t i a l of reduc-
ing canning p l a n t e f f l u e n t through the use of IQB. Peas, corn , l i m a beans,
green beans, po ta toes , c a r r o t s and bee t s were adequately blanched by IQB and
product q u a l i t y was i n most cases as good as the convent iona l ly blanched-
canned product .
-
--
The next s t e p f o r t h e development of IQB as a commercially v i a b l e blanching
system would be t h e design and i n s t a l l a t i o n of a f u l l s i z e product ion u n i t .
For tha t purpose, information contained i n t h i s r e p o r t and i n o the r published
papers on IQB could be u t i l i z e d f o r providing des ign parameters ( loading ra tes
and res idence times).
I f a p r i v a t e company o r food equipment manufacturing company does not under-
take the development of a commercial IQB u n i t , i t i s recommended t h a t EPA seek
a p a r t i c i p a n t f o r a demonstration grant .
f r eez ing and canning f a c i l i t i e s would undertake t h e p r o j e c t s i n c e the f u l l
p o t e n t i a l of I Q B as a blanching method could then be evaluated.
Preferab ly a company wi th both
2
SECTION 111
INTRODUCTION
GENERAL
Upgrading and maintenance of t h e environment i s a major p r i o r i t y
of government and p r i v a t e s e c t o r a c t i o n . For t h e s o l u t i o n t o the
envi ronmenta l problems, r e s e a r c h and development a c t i v i t i e s a re
d i r e c t e d i n t h r e e major areas: (1) i d e n t i f i c a t i o n of major p o l l u -
t i o n i n p u t from i n d u s t r i a l and o t h e r s o u r c e s , (2) development of
a l t e r n a t i v e p rocesses which e l i m i n a t e o r reduce e f f l u e n t streams,
and (3) development of e f f e c t i v e , economica l ly f e a s i b l e a t i l i z a -
t i o n o r t r ea tmen t of waste material . I n connec t ion w i t h t h e s e
three a c t i v i t i e s , i t was recognized that t h e food p r o c e s s i n g indus-
t r y needed c o n s i d e r a b l e e f f o r t . Although t h e food i n d u s t r y has
advanced t e c h n o l o g i c a l l y i n t h e conve r s ion of r a w a g r i c u l t u r a l
p roduc t s t o consumer-acceptable p r o d u c t s , l i t t l e a t t e n t i o n h a s been
g iven t o u s e of water and g e n e r a t i o n of h i g h s t r e n g t h , l a r g e volume
waste streams.
Waste management w i t h i n food p r o c e s s i n g has s e v e r a l d i s t i n c t i v e
c h a r a c t e r i s t i c s which do n o t a l l o w t h e d i r e c t a d a p t a t i o n of prac-
t i ces used i n o t h e r i n d u s t r i e s . F i r s t , p r o c e s s i n g of f r e s h a g r i -
c u l t u r a l p l a n t material i n t o consumer p roduc t s i s g e n e r a l l y sea-
s o n a l i n n a t u r e r e s u l t i n g i n an uneven demand f o r t r ea tmen t f a c i l i -
t i e s . T h i s h a s c r e a t e d d i f f i c u l t i e s s i n c e i t r e q u i r e s t h a t t h e
food p l a n t e i t h e r have i t s own t r ea tmen t f a c i l i t i e s which a r e used
s p o r a d i c a l l y o r t h a t t h e food p l a n t d i s c h a r g e i t s waste i n t o
3
munic ipa l o r o t h e r t r e a t m e n t f a c i l i t i e s c r e a t i n g unusua l peak
demands. I n e i ther case, waste t r e a t m e n t problems are somewhat
unique .
Second, the composi te waste stream gene ra t ed i n t h e food p r o c e s s i n g
p l a n t i s u s u a l l y a h i g h volume, r e l a t i v e l y low s t r e n g t h stream.
This r e s u l t s from the f a c t tha t water i s r e q u i r e d i n n e a r l y a l l
u n i t o p e r a t i o n s i n food p r o c e s s i n g and u s u a l l y l i t t l e e f f o r t i s
made t o s e g r e g a t e streams based on o r g a n i c s t r e n g t h .
BA C KGROUND
Recent r e s e a r c h a c t i v i t y des igned t o a i d the food p r o c e s s i n g i n -
d u s t r y has c e n t e r e d on i d e n t i f y i n g t h o s e u n i t o p e r a t i o n s where h i g h
s t r e n g t h , h i g h volume waste streams are gene ra t ed and development
of technology r e s u l t i n g i n r e d u c t i o n o f waste g e n e r a t i o n a t t h o s e
u n i t o p e r a t i o n s .
canning i n d u s t r y . I n the conve r s ion of r a w a g r i c u l t u r a l product t o
s h e l f - s t a b l e canned p r o d u c t s , waste streams of s i g n i f i c a n t votlume
and s t r e n g t h are gene ra t ed p e r u n i t o f p roduc t . A n a l y s i s o f the
i n d i v t d u a l u n i t o p e r a t i o n s i n canning i n d i c a t e s tha t t h e u n i t opera-
t i o n b l a n c h i n g (sometimes r e f e r r e d t o as s c a l d i n g ) i s a major s o u r c e
Receiving c o n s i d e r a b l e a t t e n t i o n has been the food
1 of e f f l u e n t . With i d e n t i f i c a t i o n o f a ma jo r p o l l u t i o n a l s o u r c e ,
c o n s i d e r a b l e research e f f o r t has been d i r e c t e d toward development
of e f f e c t i v e , economical ly f e a s i b l e b l a n c h i n g o p e r a t i o n s .
The b l anch ing o p e r a t i o n f u l f i l l s s e v e r a l n e c e s s a r y f u n c t i o n s i n c l u d -
i n g removal o f t i s s u e g a s e s ; i n a c t i v a t i o n o r a c t i v a t i o n o f enzymes,
r e d u c t i o n o f m i c r o b i a l l o a d , c l e a n s i n g of p r o d u c t , w i l t i n g of t i s s u e
t o f a c i l i t a t e packing, and e l e v a t i o n of product t empera tu re going
i n t o the r e t o r t . C u r r e n t l y , the food i n d u s t r y u s e s b o t h h o t water
and steam f o r b l anch ing . Both methods produce l i q u i d wastes h i g h
i n b iochemica l oxygen demand (BOD) and volume, and b o t h r e s u l t i n
l o s s o f water s o l u b l e n u t r i e n t s . Based on d a t a r e p o r t e d by Weckel
4
1 e t a l . f o r two Wisconsin canning p l a n t s , a 90% r e d u c t i o n i n b l a n c h e r
e f f l u e n t would r educe t o t a l p l a n t waste f low by 10 t o 20% and , more
s i g n i f i c a n t l y , reduce t o t a l p l a n t BOD by 20 t o 50%. The Na t iona l
Canners A s s o c i a t i o n e s t i m a t e d t h a t i f a new b lanch ing method which
reduced waste wa te r s t r e n g t h by 50% w e r e used f o r t h e seven vege-
t a b l e s processed i n t h e l a r g e s t tonnage , a t o t a l of approximate ly 32
m i l l i o n kg. (70 m i l l i o n pounds) of BOD and 18 m i l l i o n kg. ( 4 0 m i l l i o n
pounds) of suspended s o l i d s would be e l i m i n a t e d from t rea tmen t p l a n t
l oad ings .
2
I n t h e abatement of waste water f low and l o s s of s o l i d s from product
i n canning and f r e e z i n g p l a n t s , a s t u d y w a s i n i t i a t e d i n 1970 t o
d e s i g n a b l anch ing p rocess which would have a waste water f low of
o n l y 10% of a commercial h o t water b l anche r . The p r o j e c t w a s sup-
po r t ed by t h e U n i v e r s i t y of Wisconsin and t h e USDA, and w a s conducted
by M. E. Lazar and D. B. Lund a t t h e Western Market ing and N u t r i t i o n
Research D i v i s i o n , USDA. The p r o j e c t r e s u l t e d i n a new concept of
h e a t i n g foods and t h e a p p l i c a t i o n t o b l anch ing w a s demonstrated . The p r o c e s s , i n d i v i d u a l qu ick b l anch ( I Q B ) , r e q u i r e d f u r t h e r eva lua -
t i o n and , t h e r e f o r e , t h e Western Labora tory conducted a s t u d y u t i -
l i z i n g IQB p r i o r t o f r e e z i n g w h i l e t h e e v a l u a t i o n of I Q B f o r b lanch-
i n g p r i o r t o canning w a s conducted i n a Wisconsin canning p l a n t .
3 , 4
The I Q B p rocess i s a two-stage u n i t o p e r a t i o n . In t h e f i r s t s t a g e ,
t h e food p i e c e i s exposed t o a h e a t sou rce (condensing s team) f o r
such d u r a t i o n t h a t t h e mass-average tempera ture i s i n t h e range re-
q u i r e d f o r b l anch ing ( g e n e r a l l y g r e a t e r t han 85 C [185 F ] ) . The
p i e c e is then t r a n s f e r r e d t o a second s t a g e where t h e p i e c e i s he ld
a d i a b a t i c a l l y u n t i l t h e thermal g r a d i e n t s have e q u i l i b r a t e d t o t h e
mass average t empera tu re and t h e o b j e c t i v e s of b l anch ing have been
accomplished. The p rocess r e s u l t s i n less waste g e n e r a t i o n because :
1) steam condensa t ion i s l i m i t e d t o t h a t r e q u i r e d f o r h e a t i n g t h e
5
product i n t o t h e b l anch ing t empera tu re r ange , 2 ) t h e r e i s minimal
o p p o r t u n i t y f o r t i s s u e damage and subsequent l o s s of c e l l u l a r j u i c e s ,
and 3 ) t h e r e i s no o v e r h e a t i n g of some of t h e t i s s u e as i n deep bed
steam b lanch ing which can r e s u l t i n t i s s u e damage.
5 Lund r e p o r t e d on
canning. I n t h a t
blanched , canned ,
the a p p l i c a t i o n of I Q B t o v e g e t a b l e s p r i o r t o
s t u d y , peas , c o r n , lima beans and green beans were
s t o r e d and o b j e c t i v e l y and s u b j e c t i v e l y eva lua ted .
Eva lua t ion of IQB, IQB w i t h p red ry ing and conven t iona l p i p e b l anch ing
showed that up t o a 9 9 1 r e d u c t i o n i n waste water g e n e r a t i o n could be
achieved w i t h IQB. The s t u d y a l s o r e v e a l e d t h a t a l though p red ry ing
t o g r e a t e r t h a n a 6% weight r e d u c t i o n would f u r t h e r reduce waste
water g e n e r a t i o n , product q u a l i t y w a s a d v e r s e l y a f f e c t e d .
6
SECTION I V
OBJECTIVES
The r e s u l t s i n t h i s r e p o r t are a c o n t i n u a t i o n and e x t e n s i o n of t h e 1971
s tudy . The p r e s e n t s t u d y was unde r t aken f o r s e v e r a l r e a s o n s : 1) t o con-
f i r m t h e 1971 r e s u l t s w i t h IQB, 2) t o compare t h e IQB p rocess t o deep-bed
steam b l a n c h i n g , 3) t o app ly t h e IQB p rocess t o d i f f e r e n t v a r i e t i e s of
peas, 4 ) t o extend t h e IQB p rocess t o t h e b l anch ing of r o o t c r o p s such a s
p o t a t o e s , c a r r o t s and b e e t s , and 5) t o e v a l u a t e t h e hea t -on ly s t a g e of
t h e IQB p rocess as a b lanch ing method. O b j e c t i v e 5) w a s inc luded i n t h e
s t u d y s i n c e i t had been observed t h a t a f t e r b l anch ing , and p r i o r t o can
f i l l i n g , v e g e t a b l e s are o f t e n he ld f o r one t o two minutes d u r i n g which
t h e r m a l e q u i l i b r a t i o n could be accomplished.
h e l d i n a r e l a t i v e l y l a r g e mass t o reduce thermal l o s s e s , b l anch ing could
be accomplished. The v e g e t a b l e s used i n t h i s s tudy i n c l u d e peas (smooth
and wr ink led - sk in va r i e t i e s ) , c o r n , l i m a beans , g reen beans , p o t a t o e s ,
c a r r o t s and b e e t s .
I f t h e v e g e t a b l e s could be
7
SECT ION ' v
MATERIALS AND METHODS
PRODUCTS AND PROCESSING TIMETABLE
Products chosen f o r t h i s s t u d y were t h o s e grown and /o r processed i n
l a r g e q u a n t i t y i n Wisconsin. The 1971 s t u d y w a s done on A l s w e e t
p e a s , Midway c o r n , S l im Green g reen beans and l i m a beans ( v a r i e t y
unknown), and consequen t ly , t o v e r i f y t h e 1971 s t u d y , t h e s e p roduc t s
w e r e used i n t h i s s tudy . S i n c e t h e r e w a s concern r e g a r d i n g t h e
r e sponse of the smooth-skin pea v a r i e t y t o t h e I Q B p r o c e s s , Alaskan
peas were a l s o used. Two wr inkled-sk in v a r i e t i e s , Alsweet and Per-
f e c t i o n , were used. I n a d d i t i o n t o t h e s e f o u r v e g e t a b l e s , t h e r o o t
c r o p s , p o t a t o e s , c a r r o t s and b e e t s , were a l s o processed .
The e f f e c t of h a r v e s t d a t e on the c h a r a c t e r i s t i c s of b l a n c h e r e f -
f l u e n t w a s a s s e s s e d by making b l anch ing r u n s throughout the p rocess -
i n g season . Experiments were conducted on t h r e e days f o r peas and
c o r n , two days f o r lima beans and green beans and one day f o r po ta-
t o e s , c a r r o t s and b e e t s . Product forms and p rocess ing d a t e s are
g iven i n Table 1.
A l l p roduc t s used i n t h i s s t u d y were ob ta ined from e i t h e r t h e Sun
P r a i r i e , Merr i l l , o r Waunakee p l a n t s of t h e Oconomowoc Canning
Company, Oconomowoc, Wisconsin. Peas were t aken from t h e produc-
t i o n l i n e immediately a f t e r i n s p e c t i o n and j u s t p r i o r t o b lanching .
They were t r a n s p o r t e d t o the p i l o t p l a n t a t t h e Department of Food
Sc ience , Babcock H a l l , U n i v e r s i t y of Wisconsin-Madison under water c.
8
t o minimize p roduc t d e t e r i o r a t i o n . The b l a n c h i n g r u n w a s s t a r t e d
w i t h i n two hour s o f l e a v i n g t h e cann ing p l a n t .
Tab le 1. PRODUCT FORMS AND PROCESSING DATES
Process ing d a t e
6 I22 172
6 /26 /72
7/26/72
8/16/72
813 1/72
9/11/72
101 3/72
l O / l 1 / 72
101 9/72
10/10/72
10/31/72
111 2/72
111 7/72
P roduc t
Peas
Peas
Peas
Corn
Corn
Corn
Lima b an I
Lima bean
Green bean
Green bean
Po t a t o e s
Beets
C a r r o t s
Variety
Alsweet
Alaskan
P e r f e c t i o n
Midway
Midway
Midway
Thorogreen
Thorogreen
S l im g reen
Slim g r e e n
S u p e r i o r
Ruby queen
Nantes
Form
4 s i e v e
3 sieve
3, 4 , 5 s i e v e (mixed)
Whole k e r n e l
Whole ke rne 1
Whole k e r n e l
3 sieve
3 s i e v e
3.8 cm.
3.8 cm.
0.64 cm. (114 i n . ) s l i c e ; medium
0.64 cm. (114 i n . ) s l i ce ; medium
0.64 cm. s l i c e ; medium
Corn w a s t aken o u t o f the p r o c e s s i n g l i n e immediately b e f o r e the
c o n v e n t i o n a l b l a n c h i n g s t e p . The co rn had been washed and sc reened .
It w a s a l s o t r a n s p o r t e d t o the p i l o t p l a n t under water.
Cut g reen beans were r e c e i v e d from the Merrill, Wisconsin p l a n t and
were t r a n s p o r t e d from the p l a n t t o Madison by t r u c k . The g reen
beans were blanched and f u r t h e r processed immediately a f t e r r e c e i v -
i n g them.
Lima beans were t aken from the p r o c e s s i n g l i n e immediately a f t e r
i n s p e c t i o n and were t r a n s p o r t e d t o t h e p i l o t p l a n t under water.
9
P o t a t o e s , c a r r o t s and b e e t s were ob ta ined from t h e Waunakee p l a n t .
A l l r o o t c r o p p roduc t s had been steamed and /o r l y e - t r e a t e d , p e e l e d ,
g raded , and s l i c e d . Medium s l i c e (3 .2 - 4 .4 cm. d i a m e t e r ) w a s used
i n t h e b l anch ing s t u d i e s . T e s t s i n d i c a t e d t h a t t h e r e w a s enzymic
a c t i v i t y (peroxidase) even though t h e product had r ece ived a thermal
t r ea tmen t . The product w a s b rought t o t h e l a b o r a t o r y and processed
irmned i a t e ly . BLANCHING METHODS AND EQUIPMENT
F ive b l anch ing methods were i n v e s t i g a t e d i n t h i s s t u d y and are shown
i n Table 2 . The f i r s t method w a s IQB ( i n d i v i d u a l qu ick b l anch) .
Tab le 2. BLANCHING METHODS
Method
IQB IQB w i t h
p red ry ing
I Q B h e a t o n l y
Deep bed steam
P ipe
Peas
X
X
X
X
X
Corn
X
X
X
X
X
Lima beans
X
X
X
X
X
Green beans
X
X
X
Pota- t o e s
X
X
X
C a r r o t s Beets t
The equipment w a s t h e same as that d e s c r i b e d i n an earlier pub l i ca -
t i o n 3 and w a s on loan from t h e Western Regional Research Labora tory .
I n e s sence t h e equipment c o n s i s t e d of two
s e p a r a t e b e l t u n i t s , the f i r s t o f which w a s approximate ly 91.4 cm.
(3 f t . ) by 21.6 cm. (8.5 in . ) and the second of which w a s approxi -
ma te ly 122 cm. (4 f t . ) by 20.3 cm. (8 in . ) . The f i r s t u n i t was t h e
h e a t i n g s e c t i o n and had a feed hopper through which a s i n g l e l a y e r
o f product could b e d i scha rged o n t o the moving b e l t . The r e s i d e n c e
10
t i m e i n t h i s u n i t could be varied from 20 sec. t o 2 . 5 min. The
second u n i t , t h e hold u n i t , had a d j u s t a b l e b e l t speed and tunnel
length. Tunnel length w a s adjusted by changing t h e length of t h e
cover on t h e u n i t . I n a l l experimental runs reported h e r e , t h e
e f f e c t i v e b e l t length w a s 30.5 cm. (1 f t . ) . A diagram of t h e I Q B
u n i t i s shown i n Figure 1.
Figure 1. I Q B BLANCHING UNIT
/ M O N O L A Y E R I . A--CURTAIN -. I
Fast Belt (Live Steam Heat) HOLDING COOL ING SECT ION
SECTION (Opt ionol) Slow Belt (Chilled Air)
(Insulated, Ad ia bat i d
The h e a t u n i t w a s heated by l i v e steam which w a s d i s t r i b u t e d by two
pipe d i s t r i b u t o r s , one below and one above t h e b e l t . The d i s t r i b u t o r
below t h e b e l t d i r e c t e d t h e steam p a r a l l e l t o t h e b e l t s o product
would not be blown o f f t h e b e l t , and t h e d i s t r i b u t o r above t h e b e l t
w a s d i r e c t e d toward t h e cover on t h e u n i t . The hold s e c t i o n w a s
heated i n d i r e c t l y by steam i n two copper c o i l s , one on each w a l l
of t h e u n i t . The steam condensate and excess steam from t h i s s e c t i o n
w a s used t o preheat t h e b e l t going i n t o t h e hold s e c t i o n . The hold
s e c t i o n w a s separated from t h e h e a t u n i t by a s h o r t t r a n s f e r zone
wi th a canvas c u r t a i n .
u n i t i n t o t h e hold u n i t .
Some steam leakage d id occur from t h e h e a t
11
The I Q B u n i t w a s equipped w i t h e f f l u e n t d r a i n s on b o t h t h e h e a t and
ho ld u n i t s .
recorded s e p a r a t e l y , a n a l y s i s and r e p o r t i n g of the d a t a w e r e done
on t h e t o t a l .
Al though t h e volume o f e f f l u e n t from each u n i t w a s
The second b lanch ing method was I Q B w i t h p red ry ing .
t h e v e g e t a b l e s were cyc led through a 183 cm. (6 f t . ) long by 30.5 cm.
(1 f t . ) wide v i b r a t i n g bed d r y e r .
bu lb ) w a s passed up through t h e v e g e t a b l e bed, and t h e v e g e t a b l e s
were p r e d r i e d t o approx ima te ly a 6% weight r e d u c t i o n .
r e d u c t i o n w a s e s t a b l i s h e d based on r e s u l t s i n t h e 1971 s tudy . It
w a s found t h a t a t h i g h e r weight r e d u c t i o n i r r e v e r s i b l e d e h y d r a t i o n
occur red ( i . e . the product would n o t r e h y d r a t e t o i n i t i a l w e t weight )
and product q u a l i t y w a s a d v e r s e l y a f f e c t e d (most n o t a b l y through
e x c e s s i v e s k i n r u p t u r e o r e x c e s s i v e browning).
For p r e d r y i n g ,
A i r a t 71-82 C (160-180 F) ( d r y
A 6% weight
The t h i r d b l anch ing method (IQB h e a t o n l y ) u t i l i z e d on ly t h e h e a t
b e l t of t h e IQB u n i t . Immediately a f t e r go ing through t h e h e a t i n g
u n i t t h e product was d i scha rged i n t o p l a s t i c bucke t s . Product w a s
h e l d i n t h e bucke t s u n t i l canning.
The f o u r t h method w a s deep bed steam blanching . The h e a t s e c t i o n of
t h e IQB u n i t w a s used f o r t h i s method a l s o . The p roduc t w a s d i s -
charged on to t h e b e l t i n a 6.4-7.6 cm. (2.5-3 i n . ) deep l a y e r .
Residence time i n t h e u n i t w a s 2.5 min. f o r a l l deep bed b l anch ing
t r ia l s .
The f i f t h b l anch ing method e v a l u a t e d w a s t h e commercial method--
p i p e b l anch ing . The u n i t c o n s i s t e d of 122-152 m. (400-500 f t . ) of
11.4 cm. (4.5 in . ) d i ame te r s t a i n l e s s steel p ipe . The l e n g t h w a s
v a r i a b l e so t h a t t h e r e s i d e n c e time could be a d j u s t e d . Product w a s
metered i n t o t h e p i p e a t a p r e s e t rate so t h a t t h e water t o product
r a t i o w a s c o n s t a n t . A f t e r b l anch ing , t h e product w a s dewatered a t
12
a dewa te r ing reel and was f u r t h e r processed . The b lanch water w a s
t h e n sc reened , make-up water w a s added and t h e water r e c y c l e d i n t o
t h e p ipe . Water and v e g e t a b l e s i n t h e p i p e b l a n c h e r were h e a t e d
by d i r e c t steam i n j e c t i o n .
Blanching t imes used i n t h e IQB h e a t / h o l d s e c t i o n s were determined
by making s imple o b s e r v a t i o n s on t h e p i p e b l anch ing o p e r a t i o n .
peas , i t w a s observed t h a t conven t iona l p i p e b l anch ing o p e r a t i o n
r e s u l t e d i n pe rox idase i n a c t i v a t i o n and, t h e r e f o r e , pe rox idase i n -
a c t i v a t i o n w a s t h e c r i t e r i o n f o r e s t a b l i s h i n g h e a t / h o l d times i n
IQB.
d e s c r i b e d i n Lund et a. t u r e i n p i p e b l anch ing w a s approximate ly 77 C (170 F) and, conse-
q u e n t l y , h e a t / h o l d times were chosen t h a t would r e s u l t i n a f i n a l
co rn o r lima bean t empera tu re of 77 C. Green beans w e r e a l s o p i p e
blanched a t 77 C b u t t h e conven t iona l IQB p rocess could n o t be used.
With g reen beans , t h e f u n c t i o n of b l anch ing i s t o act ivate t h e enzyme
p e c t i n methyl esterase which p reven t s s lough ing of t h e g reen bean
f o l l o w i n g canning. S ince t h e enzyme i s i n a c t i v a t e d a t t empera tu res
above 82 C (180 F ) , t h e IQB h e a t s e c t i o n could n o t be h e a t e d w i t h
100 C (212 F) steam. There fo re , a steam-air m i x t u r e a t 79 C (175 F)
w a s used i n t h e I Q B h e a t i n g s e c t i o n .
t h a t would r e s u l t i n a n e q u i l i b r a t e d t empera tu re of 77 C. For pota-
t o e s , c a r r o t s and b e e t s , a d i r e c t comparison t o p i p e b l anch ing could
n o t b e made s i n c e t h e s e p roduc t s are n o t u s u a l l y blanched p r i o r t o
canning.
r e t o r t i n g i s i n t h e p e e l i n g o p e r a t i o n . These p roduc t s were inc luded
i n t h e IQB and deep-bed expe r imen t s , however, s i n c e they are blanched
p r i o r t o f r e e z i n g and some p r o c e s s o r s have exper ienced u n d e s i r a b l e
c o l o r changes ( p a r t i c u l a r l y w i t h b e e t s and p o t a t o e s ) which can be
avoided by b l anch ing a f t e r s l i c i n g o r d i c i n g .
were chosen such t h a t pe rox idase w a s i n a c t i v a t e d . For deep-bed
b l anch ing , a l l v e g e t a b l e s were blanched f o r 2.5 minu tes , t h e maximum
For
Appropr i a t e h e a t / h o l d t imes were de termined by t h e procedure
For c o r n and l ima beans , water tempera- 4
Heat /hold times were chosen
The o n l y h e a t t r e a t m e n t t h e s e p roduc t s receive p r i o r t o
Blanching c o n d i t i o n s
13
r e s i d e n c e t i m e of t h e I Q B h e a t s e c t i o n . Blanching c o n d i t i o n s f o r
a l l v e g e t a b l e s are shown i n Table 3.
Table 3. BLANCHING TIMES AND TEMPERATURESa
Commodity
Peas
Corn
L ima b earis
Green beans
Po ta toes
C a r r o t s
Beets
IQB
30 sec /100 C h e a t
45 s e c hold
20 sec /100 C h e a t
30 s e c hold
20 sec /100 C h e a t
80 sec hold
20 sec /82 C h e a t
80 s e c hold
60 sec/100 C h e a t
60 sec hold
45 sec /100 C h e a t
60 s e c hold
45 sec/100 C h e a t
60 s e c hold
Heat on ly
30 sec /100 C
D e e D bed
2.5 min/100 C
2.5 min/100 C
2.5 m i d 1 0 0 C
2.5 min/82 C
2.5 min/100 C
2.5 min/100 C
2.5 min/100 C
P ipe
4 m i d 9 3 c
1.5 min/77C
4 min/77 c
2 m i d 7 7 C
a A l l t ime / t empera tu re combina t ions r e s u l t e d i n n e g a t i v e pe rox idase excep t f o r green beans. Time/Temperature (C).
For each expe r imen ta l r u n , t h r e e 9.09 kg. (20 l b . ) ba t ches of t h e
v e g e t a b l e were t r e a t e d by one of t h e f o u r steam b lanch ing methods.
I n i t i a l we igh t , weight a f t e r d r y i n g ( i f t h e product was p r e d r i e d ) ,
and weight a f t e r b l anch ing were recorded . For each 9.09 kg. r u n , a l l
waste water gene ra t ed by p r o c e s s i n g t h e v e g e t a b l e i n t h e b l a n c h e r was
measured. A composite sample of t h e waste water was s u b j e c t e d t o
a n a l y s i s f o r t h e fo l lowing : 1) BOD5, 2 ) COD, 3) t o t a l s o l i d s , 4) suspended s o l i d s , 5 ) s o l u b l e phosphorus, 6 ) t o t a l phosphorus, 7)
t o t a l o rgan ic n i t r o g e n , 8) NH3-Nitrogen, 9) NO3-Nitrogen, 10) NO2-
N i t rogen , 11) v o l a t i l e s o l i d s , 12) suspended v o l a t i l e s o l i d s , and
14
13) pH. P a r t of t h e a n a l y s e s were performed by t h e Wisconsin Depart-
ment of Na tu ra l Resources. I n a l l c a s e s t h e s t anda rd methods f o r
a n a l y s e s were used . 6
In o r d e r t o r e p o r t waste water g e n e r a t i o n on t h e b a s i s of amount of
product p rocessed , a b l ank was determined f o r each run by o p e r a t i n g
t h e equipment w i t h t h e steam on and t h e b e l t s moving f o r a pe r iod
of time e q u a l t o t h e time t o p rocess t h e 9.09 kg. l o t . Equipment
e f f l u e n t (due t o h e a t l o s s e s from t h e equipment, h e a t i n g t h e b e l t and
any water c a r r i e d i n t h e steam l i n e ) was measured and t h i s v a l u e sub-
t r a c t e d from t h e volume gene ra t ed d u r i n g t h e a c t u a l run. A l l a n a l y s i s
v a l u e s were c o r r e c t e d by t h e r e s u l t i n g d i l u t i o n f a c t o r .
f o l l o w i n g b l a n c h i n g , samples were f i l l e d i n t o 303 x 406 cans t o t h e
Immediately
a p p r o p r i a t e f i l l we igh t , b r i n e added, cans s e a l e d and r e t o r t e d i n a
S t e r i t o r t fo l lowing t h e h e a t / c o o l p rocess used i n t h e canning p l a n t .
For t h e p ipe b l a n c h e r , e f f l u e n t was c o l l e c t e d a t t h e dewa te r ing ree l
and s u b j e c t e d t o t h e same a n a l y s e s as o t h e r samples. Water usage w a s
monitored by a water meter i n t h e water make-up l i n e and was recorded
d a i l y . By knowing t h e d a i l y case pack on t h e l i n e , t h e l i t e r s of
water p e r case of product could be c a l c u l a t e d . S i n c e t h e p i p e
b l anch ing water was hea ted by d i r e c t steam i n j e c t i o n , t h e e f f l u e n t
gene ra t ed by t h e system w a s l a r g e r t h a n t h a t c a l c u l a t e d from t h e
water make-up r e a d i n g s . To a d j u s t f o r t h e steam condensa t ion i n
h e a t i n g t h e product up, i t was assumed t h a t 4.23 kg. (9.3 l b . ) of
steam would condense f o r eve ry 45.5 kg. (100 l b . ) of product be ing
hea ted 38.0 C (100 F) . This r e s u l t e d i n 91.7 l i t e r s of steam con-
d e n s a t i o n p e r kkg. of product (22 g a l / t o n ) . This v a l u e has been
added t o a l l p i p e b l a n c h e r v a l u e s as c a l c u l a t e d from water meter
r e a d i n g s . Waste g e n e r a t i o n r e p o r t e d f o r t h e p i p e b l anch ing sys tem
w i l l s t i l l be low s i n c e t h i s does n o t accoun t f o r h e a t l o s s e s from
t h e p i p i n g system. However, f o r t h e system w e monitored h e a t l o s s e s
would probably n o t c o n t r i b u t e more than 8.3-20.9 l . /kkg. (2-5 g a l / t o n )
of product processed . 15
To i n s u r e t h a t r e p r e s e n t a t i v e samples of waste water were be ing
c o l l e c t e d from t h e p i p e b l a n c h e r , on some occas ions (at least two
days f o r each v e g e t a b l e ) , water samples w e r e c o l l e c t e d a t two-hour
i n t e r v a l s . R e s u l t s i n d i c a t e d that w i t h i n two hour s of s t a r t - u p t h e
b l a n c h e r water w a s i n s t e a d y state. T h e r e f o r e , a l l samples were
t aken a t least two hour s afker s t a r t - u p . For l a te r e v a l u a t i o n and
comparison, several cases of canned v e g e t a b l e s processed a t t h e same
time t h e expe r imen ta l samples were processed were brought t o t h e
l a b o r a t o r y .
PRODUCT EVALUATION
A f t e r b l anch ing , t h e product w a s hand packed i n t o 303 x 406 c a n s ,
b o i l i n g water and t h e a p p r o p r i a t e volume of c o n c e n t r a t e d b r i n e were
added and t h e cans were s e a l e d . The cans w e r e t h e n t h e r m a l l y proc-
e s sed i n a S t e r i t o r t u s i n g r o t a t i o n speed and h e a t / c o o l t i m e s iden-
t i c a l t o t h o s e used i n t h e canning p l a n t . Product w a s t h e n s t o r e d
a t 32 C (90 F) a l o n g w i t h c o n v e n t i o n a l l y processed product which had
been o b t a i n e d from t h e canning p l a n t . Product e v a l u a t i o n s were con-
duc ted a t 1, 3 , 6 and 9 months' s t o r a g e . The tes ts performed on
each p roduc t are shown i n Table 4 . Standard procedures were followed
f o r a l l tes ts . The method of Van Buren e t a l .7 was used f o r t h e
s lough tes t on green beans. A t each e v a l u a t i o n a f i v e - c a n subsample
f o r each expe r imen ta l p rocess and conven t iona l p rocess w a s ana lyzed .
Product q u a l i t y w a s a s s e s s e d by t r i a n g l e tas te t e s t comparing each
e x p e r i m e n t a l l y processed p roduc t t o t h e co r re spond ing c o n t r o l p rocess
product (canned product ob ta ined from t h e canning p l a n t ) . T a s t e
t e s t i n g w a s conducted i n t h e Sensory Eva lua t ion Labora to ry of t h e
Department of Food Sc ience u s i n g pe r sonne l who were t r a i n e d i n
senso ry e v a l u a t i o n . D i f f e r e n c e s could be a s s e s s e d on t h e b a s i s of
c o l o r , t e x t u r e o r f l a v o r and p r e f e r e n c e w a s no ted . To s t r e a m l i n e
t h e p r e s e n t a t i o n of senso ry e v a l u a t i o n d a t a , two p i e c e s of informa-
t i o n were gene ra t ed . The f i r s t c o n s i s t s of t h r e e numbers s e p a r a t e d
1 6
Table 4 . PRODUCT EVALUATION TESTS
T e s t
Taste pane l
Can vacuum
Drained weight
B r i n e sediment
Slough
P e r c e n t s p l i t s
Peas
X
X
X
X
X
Corn
X
X
X
Lima beans
X
X
X
Green beans
X
X
X
X
X
Pota- t o e s
X
X
X
C a r r o t s Beets +- by s l a s h e s such as 10/5/5. The f i r s t number (10) is t h e number of
c o r r e c t judgments which p r e f e r r e d t h e e x p e r i m e n t a l l y blanched canned
p roduc t ; t h e second number (5) i s t h e number of c o r r e c t judgments
which p r e f e r r e d t h e c o n t r o l sample; and t h e las t number (5) i s t h e
number of c o r r e c t judgments which showed no p r e f e r e n c e .
p i e c e of i n fo rma t ion w a s t h e level of d i s t i n c t i o n between samples.
There w a s e i t h e r no s i g n i f i c a n t d i f f e r e n c e (NS) o r d i f f e r e n c e s
were i d e n t i f i a b l e a t t h e 0.1%, 1% o r 5% level.
The second
17
SECTION V I
RESULTS AND DISCUSS I O N
FLOW V A R I A B I L I T Y OF BLANCHING WASTES
During t h e p r o c e s s i n g season d a i l y water meter r e a d i n g s were recorded
f o r water usage i n t h e p i p e b l a n c h e r f o r peas, c o r n , and green beans .
Examination of t h e d a t a showed t h a t t h e most c o n s i s t e n t c h a r a c t e r i s t i c
w a s t h e extreme v a r i a b i l i t y i n water used p e r c a s e o r t o n of v e g e t a b l e .
The d a t a were s o scattered t h a t i t i s tenuous a t b e s t t o draw con-
c l u s i o n s . However , i n t h e hope of comparing IQB t o p i p e b l anch ing , ave rage water usage rates w e r e c a l c u l a t e d . An example of v a r i a b i l i t y
of d a t a i s t h e r ange of d a t a r e p o r t e d f o r green bean b l anch ing . On
8/24/72 t h e r e w a s a r e p o r t e d 24.2 l . / c a s e (6.4 g a l / c a s e ) wa te r usage
i n t h e p i p e b l a n c h e r ; whereas on 9/16/72 on ly 0.45 l . / c a s e (0.12 g a l /
c a s e ) w a s recorded . Th i s i s over a 50- fo ld d i f f e r e n c e ! I n pea
b l a n c h i n g , on 6 /27/72 , 6.6 l ./case (1.75 g a l / c a s e ) w a s recorded f o r
t h e p i p e b l anche r compared t o 0 . 3 3 l . / c a s e (0.088 g a l / c a s e ) on
7 /19/72 , a 20- fo ld d i f f e r e n c e . This tremendous v a r i a b i l i t y con-
t r i b u t e s t o many m i s i n t e r p r e t a t i o n s r e g a r d i n g water usage i n b lanch-
i n g o p e r a t i o n s . One f a c t o r r e s p o n s i b l e f o r v a r i a b i l i t y i s incomple te
knowledge of t h e b l anch ing system. In o u r c a s e w e were n o t informed
t h a t t h e b l a n c h e r could be f i l l e d from two s e p a r a t e s o u r c e s , one a t
t h e i n l e t end and one a t t h e d i s c h a r g e end. Consequently, w e on ly
monitored water i n l e t from one source . Once t h i s w a s recognized w e
were a b l e t o s c r e e n t h e d a t a t o a s s u r e t h a t a r e p r e s e n t a t i v e v a l u e
w a s r e p o r t e d . A second f a c t o r r e s p o n s i b l e f o r v a r i a b i l i t y of f low i s
t h e l a c k of c o n t r o l on t h e b l anch ing u n i t o p e r a t i o n . Many t i m e s t h e
/
18
b lanche r i s n o t equipped w i t h a f low r e g u l a t i n g d e v i c e b u t r a t h e r
t h e r e i s j u s t a water l i n e b r i n g i n g water i n t o t h e system. The
foreman o r worker mere ly opens a water valve t o the b l a n c h e r and h a s
no guidance as t o the a p p r o p r i a t e f low ra te t o use . T h e r e f o r e , on
some occas ions f low i s ve ry h i g h , w h i l e on o t h e r s it i s v e r y low.
I n a d d i t i o n t o t h e v a r i a b i l i t y of f low between days , t h e r e i s a l s o
v a r i a b i l i t y of f low w i t h i n a day, An example of water f low from
blanching d u r i n g one day o f p rocess ing f o r p e a s , c o r n , g reen beans
and lima beans i s shown i n Table 5. The p e r c e n t t o t a l s o l i d s of t h e
b l a n c h e r e f f l u e n t i s a l s o g iven . It can b e seen t h a t t h e r e i s con-
s i d e r a b l e v a r i a b i l i t y i n the water usage p a t t e r n throughout the
p rocess ing day. T h i s v a r i a b i l i t y r e f l e c t s the c y c l i c n a t u r e of t h e
b l anch ing o p e r a t i o n i n t h a t t h e b l a n c h e r i s g e n e r a l l y d r a i n e d and
r e f i l l e d several times d u r i n g t h e o p e r a t i n g day. This c l eanup is
n e c e s s i t a t e d by t h e fac t t h a t t h e s o l i d s leached from t h e t i s s u e
d u r i n g b l anch ing undergo o x i d a t i v e and thermal d e g r a d a t i o n t o v e r y
f l a v o r f u l compounds. These compounds can produce o f f - f l a v o r i n t h e
f i n a l p roduct u n l e s s t hey are removed p e r i o d i c a l l y . For peas t h e
b l a n c h e r was r e f i l l e d eve ry 6-8 h o u r s , f o r co rn e v e r y 12 h o u r s , and
f o r lima beans eve ry s i x hours . For g reen beans t h e b l anche r w a s
r e f i l l e d eve ry s i x hour s b u t no make-up water w a s added between re-
f i l l s . Under t h e s e c o n d i t i o n s t h e t o t a l s o l i d s i n t h e b l anch water
v a r i e s c o n s i d e r a b l y , f o r example, from 0.55% TS t o 1.35% TS. With
t h e o t h e r v e g e t a b l e s t h e % TS i s k e p t r e l a t i v e l y c o n s t a n t by t h e
a d d i t i o n of make-up water.
The d a t a r e p o r t e d i n Table 5 f o r l i m a beans are from t h e 1971 s tudy .
No d a t a are a v a i l a b l e on water usage f o r lima beans f o r 1972 due t o
a change i n b l anch ing c o n d i t i o n s . I n 1971, t h e water make-up ra te
was approximate ly 76 l . /case (20 g a l / c a s e ) , about t e n t imes h i g h e r
t han that r e p o r t e d f o r t h e o t h e r v e g e t a b l e s . A t t h e end of t h e 1971
19
Table 5. HOURLY MAKE-UP F'LOW RATES AND TOTAL SOLIDS CONTENT OF PIPE BLANCHER WATER FOR PEAS, CORN, LIMA BEANS AND GREEN BEANS
Time (hrs)
2
2.5 3
3.5
4 6
8
10 12
14 16
18
Peas % TS 1 . h
2.31 719 2.15 590
2.24 795 2.90 636
2.90 689 2.70 708
- Corn % TS 1. /hr
2.47 1703
2.58 1363 2.50 1363 2.30 1363
2.05 1817
1.09 1249
2.24 1400 3.00 1400 2.79 4126 2.12 265 2.26 2 725
1.95 1779
Lima beans
Yo TS 1. /hr
0.59 24600
0.39 20250
0.62 30470
0.43 15030 0.37 20530
Green beans
% TS l./hr
0.71 8880
1.12 0
0.63 6230 1.01 0
0.97 0
0.55 9750 1.23 0
1.35 0
processing season this observation was made to the plant personnel
who immediately sought to correct the situation for 1972. The high water usage rate was the result of the foaming problem associated with lima bean blanch water. In 1972, several corrective actions were taken: 1) use of an antifoam agent in the blanch water, 2) use of hard water instead of soft and 3) maintenance of a full reservoir prior to the pump (eliminated air entrapment). Since the water make-up line was hard water and fed several pieces of equipment si-
multaneously, it was impossible to monitor water addition rates. How- ever, after conversations with plant personnel, it was estimated that water usage rates for lima beans were about the same as those for
corn.
20
I
CONDENSATION OF RAW DATA
I n t h i s t ype of s t u d y volumes of r a w d a t a can be ob ta ined and much
of i t can , i n t u r n , be m u l t i p l i e d c o n s i d e r a b l y by c a l c u l a t i o n s . I n
o r d e r t o s i m p l i f y t h e examination of d a t a and t o r each t h e r e a l l y
p e r t i n e n t i n fo rma t ion ob ta ined i n t h i s s t u d y , t h e r a w d a t a were con-
densed and o n l y t h e p e r t i n e n t c a l c u l a t i o n s were performed. Many
more c a l c u l a t i o n s can be done b u t t h e y do n o t serve t o demonst ra te
more e f f e c t i v e l y t h e r e s u l t s con ta ined h e r e i n .
The r a w d a t a f o r each of t h e b l anch ing runs are g iven i n t h e Appendix
i n Tables A 1 - A 1 4 . The f i r s t t a b l e f o r each product p r e s e n t s t h e
p h y s i c a l c h a r a c t e r i s t i c s of t h e run such as b e l t l o a d i n g s , e f f l u e n t
gene ra t ed (expressed as l . / c a s e ) , p roduct y i e l d and s o l i d s los t as
product . " B e l t loading ' ' r e s u l t s w i l l be d i s c u s s e d i n a l a t e r sec -
t i o n . " E f f l u e n t gene ra t ed" w a s c a l c u l a t e d from t h e volume of waste
c o l l e c t e d p e r u n i t of r a w product . "Product y i e l d " i s t h e r a t i o of
blanched weight t o i n i t i a l weight t i m e s one hundred. "So l ids l o s t
as product" r e p r e s e n t s t h e s o l i d s i n t h e b l anch water expressed on
t h e b a s i s of product e q u i v a l e n t s . For t h i s c a l c u l a t i o n i t w a s
assumed t h a t peas were 20% t o t a l s o l i d s , co rn w a s 25%, lima beans
were 32.5%, green beans were lo%, p o t a t o e s were 20.2%, c a r r o t s were
11.8% and b e e t s w e r e 12.7%. These v a l u e s are from USDA Handbook
No. 8.
The second t a b l e p r e s e n t i n g r a w d a t a on each b l anch ing run f o r each
product c h a r a c t e r i z e s t h e e f f l u e n t . A l l of t h e d a t a are expressed
as ppm o r % and r e p r e s e n t t h e c o n c e n t r a t i o n of t h e p a r t i c u l a r com-
ponent i n t h e e f f l u e n t . A more conven ien t way of e x p r e s s i n g t h e s e
d a t a f o r d i s c u s s i o n purposes i s t o e x p r e s s t h e water c h a r a c t e r i s t i c s
on t h e b a s i s of kkg. of processed product . This w a s done and s e l e c t e d
c h a r a c t e r i s t i c s w i l l be p re sen ted i n later d i s c u s s i o n s .
21
The n o t a t i o n used i n t h e t a b l e s t o d e s c r i b e t h e b l anch ing treatment is r e l a t i v e l y s t r a i g h t f o r w a r d . IQB s t a n d s f o r i n d i v i d u a l qu ick
b l anch , t h e "-0" o r "-number" r e p r e s e n t s t h e p red ry ing t r e a t m e n t (0 means no p red ry ing ; number expresses t h e % weight r e d u c t i o n i n p re -
d r y i n g ) , t h e "-sect' represents t h e h e a t on ly p rocess of IQB and deep
bed r e p r e s e n t s deep bed steam b lanch ing . Pipe r e f e r s t o p ipe b lanch-
i n g , t h e c o n t r o l .
Examination of t h e raw data shows t h a t several v a r i a b l e s had no
e f f e c t on b l anch ing c h a r a c t e r i s t i c s of t h e product . For peas t h e r e
d i d no t appear t o be an e f f e c t due t o var ie ty o r h a r v e s t d a t e on
b l anch ing c h a r a c t e r i s t i c s . T h e r e f o r e , t h e data w i t h i n one b l anch ing
t r e a t m e n t could be averaged t o s i m p l i f y p r e s e n t a t i o n . S i m i l a r l y w i t h
c o r n , t h e r e d i d no t appear t o be a n e f f e c t of harvest: d a t e . There-
f o r e , t h e d a t a were averaged w i t h i n each b l anch ing t r e a t m e n t . Lima
beans , g reen beans , p o t a t o e s , b e e t s and c a r r o t s a l s o showed no h a r -
vest da te e f f e c t . T h e r e f o r e , ave rages are used i n d i s c u s s i n g t h e
r e s u l t s . It should be po in ted o u t t h a t t h e v a r i a b l e h a r v e s t d a t e
i s n o t t h e s a m e as t h e v a r i a b l e m a t u r i t y . For example, a l though
co rn may be h a r v e s t e d on d i f f e r e n t d a t e s i t may be of t h e same ma-
t u r i t y and consequen t ly t h e r e can s t i l l be a m a t u r i t y e f f e c t .
co rn i n p a r t i c u l a r , i t might be suspec ted t h a t t h e r e would be a d i f -
f e r e n c e i n b l a n c h e r e f f l u e n t f o r mature v e r s u s immature co rn .
With
Although s e v e r a l parameters were measured on t h e b l a n c h e r e f f l u e n t
on ly a few w i l l be d i s c u s s e d . Probably t h e most impor tan t parameters
are BOD5, t o t a l o r g a n i c n i t r o g e n and t o t a l phosphorus
r e l a t i v e c o n c e n t r a t i o n s of t h e s e t h r e e components are used t o assess
t h e response of t h e waste t o b i o l o g i c a l waste t r e a t m e n t . Consequently
i n d i s c u s s i n g t h e d a t a , on ly t h e s e t h r e e parameters w i l l be d i s c u s s e d .
s i n c e t h e
22
PEA BLANCHING
A sunnnary of t h e pea b lanch ing d a t a is g iven i n Table 6.
b Blanching t rea tmen t
IQB-6 9
IQB-0
30 Sec
Deep bed
Pipe
Tab le 6.
E f f l u e n t g e n e r a t i o n (1. /kkg)
146
225
209
3 13
3 84
SUMMARY OF PEA BLANCHING DATA^
BOD5 (kg / k k d
1.8
2.6
2.5
4.3
3.0
T o t a l o rgan ic n i t r o g e n (kg /kkg)
0.09
0.13
0.13
0.22
0.17
T o t a l phosphorus
(kg /kkg)
0.02
0.04
0.03
0.05
0.05
Product y i e l d
(%I
88.8
89.3
90.4
83.3 --
S o l i d s l o s t as product
(%)
1.53
2.07
2.09
3.11 --
Expressed p e r kkg of blanched p roduc t . complete d a t a .
IQB-0 means I Q B w i t h o u t p red ry ing . 30 Sec means h e a t s e c t i o n o n l y of IQB. Deep bed means deep bed steam b lanch ing . P ipe means p i p e b l anch ing .
See Tables A 1 and A2 f o r a
bIQB-6.9 means IQB w i t h a 6.9% weight r e d u c t i o n p r i o r t o b l anch ing .
The f i r s t impor tan t o b s e r v a t i o n is t h a t a l l of t h e steam b lanch ing
methods r e s u l t e d i n less e f f l u e n t g e n e r a t i o n t h a n p i p e b l anch ing .
P red ry ing by a n ave rage of 6.9% weight r e d u c t i o n reduced waste genera-
t i o n by 62% w h i l e deep bed b l anch ing reduced t h e waste stream by 18%.
A s expec ted , p red ry ing showed less g e n e r a t i o n of waste than IQB o r
30 sec. h e a t t r e a t m e n t s . P red ry ing t h e s u r f a c e of t h e pea allowed
t h e condensed steam t o r e h y d r a t e t h e s u r f a c e r a t h e r t h a n running o f f .
The IQB-0 and 30 sec. h e a t t r e a t m e n t s r e s u l t e d i n n e a r l y t h e same
t o t a l e f f l u e n t g e n e r a t i o n i n d i c a t i n g t h a t most of t h e e f f l u e n t i s
gene ra t ed i n t h e h e a t s e c t i o n of IQB from steam condensa t ion .
The v a l u e of 225 l . / kkg (54 g a l / t o n ) r e p o r t e d h e r e f o r IQB-0 a g r e e s
q u i t e w e l l w i t h t h e 200 l . / kkg (48 g a l / t o n ) f o r steam b lanch ing peas
23
as r e p o r t e d by R a l l s e t a1.8 and w i t h t h e t h e o r e t i c a l v a l u e ob ta ined
when a mass b a l a n c e i s performed on t h e u n i t o p e r a t i o n . In R a l l s
e t a l . s t u d y t h e load ing r a t e w a s on ly 2 kg/m2 (0 .4 pound / f t ) of
b e l t s u g g e s t i n g t h a t t h e y had t h e e q u i v a l e n t of an IQB h e a t s t a g e .
The r e s i d e n c e t i m e , however, w a s much longe r than t h e 30 s e c . used
i n IQB.
2
The deep bed steam b lanch ing t r e a t m e n t r e s u l t e d i n 313 l . / kkg (75
g a l / t o n p r o d u c t ) , n e a r l y 50% more t h a n IQB b l anch ing . The g r e a t e r
e f f l u e n t g e n e r a t i o n i s due t o two f a c t o r s : 1) o v e r h e a t i n g of some
of t h e t i s s u e r e s u l t i n g i n g r e a t e r j u i c e l o s s and 2 ) a lower s u r f a c e
water h o l d i n g c a p a c i t y of t h e hea ted bed of peas .
i s e v i d e n t from t h e h i g h e r BOD5, n i t r o g e n and phosphorous v a l u e s
r e p o r t e d f o r t h e deep bed t r e a t m e n t . A l so , t h e s o l i d s l o s t as
product i s n e a r l y 50% more than f o r IQB. The second f a c t o r , lower
water h o l d i n g c a p a c i t y of t h e bed of peas, i s a r e s u l t of t h e h i g h e r
mass ave rage t empera tu re of t h e peas i n t h e deep bed t r ea tmen t .
With t h e r e s i d e n c e time of 2.5 minutes t h e bed t empera tu re w a s much
h i g h e r and consequen t ly t h e v i s c o s i t y of t h e water and t h e s u r f a c e
t e n s i o n of waterwere lower r e s u l t i n g i n more water running o f f .
The f i r s t f a c t o r
The 384 l . / kkg (92 g a l / t o n ) r e p o r t e d h e r e i s much lower than o t h e r
v a l u e s r e p o r t e d f o r water b l anch ing sys tems.
a waste water g e n e r a t i o n of 1420 l . / kkg (340 g a l / t o n ) f o r a p i p e
b l anch ing w h i l e Ra l l s e t a1.8 r e p o r t e d 4170 l . / kkg (1000 g a l / t o n )
f o r a d r a p e r - t y p e w a t e r b l anche r . The v a l u e r e p o r t e d h e r e r e f l e c t s
a ve ry impor tan t concept recognized by t h e canning p l a n t pe r sonne l .
They have c u t back t h e water make-up on a r e g u l a r b a s i s w h i l e con-
t i n u o u s l y checking p roduc t q u a l i t y .
water usage d r a s t i c a l l y through c o n t r o l on t h e p rocess .
v a l u e r e p o r t e d by Ra l l s e t a1.8 may n o t n e c e s s a r i l y r e f l e c t e x c e s s i v e
waste g e n e r a t i o n w i t h t h e d r a p e r - t y p e b l anche r . Rather i t may re-
f l e c t t h e ba t ch - type n a t u r e of t h e way i n which t h e experiment w a s
Weckel e t al.' r e p o r t e d
This has allowed them t o c u t
The h i g h
24
conducted. Perhaps more peas could have been processed i n t h e
blancher before t h e water had t o be changed. Also, a feed and bleed
system would reduce water usage.
The BOD reported h e r e f o r steam and pipe blanching corresponds q u i t e
w e l l t o t h e data of Ralls e t a l . . They reported a COD of 8 . 3 kglkkg
(16.6 lb / ton ) f o r steam blanching and i f w e assume a BODICOD r a t i o of
0.60 t h i s would r e s u l t i n a BOD of about 5 kg/kkg (10 l b / t o n ) . The 5 BOD/nitrogen/phosphorous r a t i o w a s s u r p r i s i n g l y cons tan t wi th an
average of 8214.411 (range 55-117/3.1-7.6/1.This i n d i c a t e s t h a t t h i s
waste h a s an adequate carbon t o n i t r o g e n t o phosphorous r a t i o f o r b i o l o g i c a l
t reatment .
8 5
F i n a l l y , t h e product y i e l d i s given i n Table 6. Product y i e l d w a s
q u i t e cons tan t between t h e IQB t reatments b u t deep bed steam blanch-
ing r e s u l t e d i n considerab y g r e a t e r l o s s of y i e l d . For deep bed
steam blanching t h i s lower y i e l d is due t o t i s s u e breakdown and
lower water holding c a p a c i t y of t h e peas , as explained e a r l i e r .
For IQB blanching most of t h e weight l o s s i s a l s o a r e s u l t of t h e
lower moisture holding capac i ty of t h e sur face . From experiments
done i n 1971, a cold pea can hold up t o 15% by weight as s u r f a c e
moisture. After blanching, t h e s u r f a c e is n e a r l y dry even though
steam has condensed on t h e sur face .
up t o 6% by weight as water and thus l o s s of s u r f a c e moisture would
account f o r up t o 9% weight l o s s .
The h o t s u r f a c e can hold only
The product y i e l d va lue would appear t o be too low f o r economic con-
s i d e r a t i o n of I Q B ; however, t h e process should be evaluated pr imar i ly
on t h e b a s i s of s o l i d s l o s t s i n c e t h i s va lue r e p r e s e n t s t r u e product
l o s s . Product y i e l d r e f l e c t s t h e loss of sur face water a s w e l l as
product loss . It would be a n t i c i p a t e d t h a t h o t water blanching
would r e s u l t i n even g r e a t e r s o l i d s l o s s as repor ted by Lee . 9
25
The r e s u l t s of o b j e c t i v e e v a l u a t i o n of peas i s shown i n Table 7.
It i s n o t i c e d t h a t ail cf t h e can vacuum v a l u e s f o r t h e e x p e r i m e n t a l l y
blanched samples are h i g h e r than t h a t f o r p i p e blanched samples. Th i s
i s due t o t h e f a c t t h a t t h e f i l l water t empera tu re w a s h i g h e r i n t h e
e x p e r i m e n t a l l y blanched samples . I n t h e l a b o r a t o r y t h e f i l l water
t empera tu re w a s n e a r 96 C (205 F) whereas i n t h e canning p l a n t i t
w a s 82-88 C (180-190 F) . Th i s d i f f e r e n c e could account f o r t h e
d i f f e r e n c e i n can vacuum. Th i s demons t r a t ed , however, t h a t peas
could be s u c c e s s f u l l y steam blanched p r i o r t o canning and t h a t t h e r e
w a s adequa te a i r removal from t h e t i s s u e . The can vacuum dec reased
s l i g h t l y upon s t o r a g e , as expec ted .
The d r a i n e d we igh t s of a l l steam blanched samples were h i g h e r t h a n
t h o s e of t h e c o n t r o l . This w a s n o t l i k e l y t h e r e s u l t of t h e b l anch ing
t r e a t m e n t b u t r a t h e r was t h e r e s u l t of a s l i g h t o v e r f i l l . The f i l l
weight w a s 292.5 g. (10.3 ounces) and t h e r e s u l t i n g d r a i n e d weight
averaged 320.9 g. (11.3 o u n c e s ) , a 28 g. (one ounce) weight g a i n
upon r e t o r t i n g and coo l ing .
Br ine sediment v a l u e s r e f l e c t a problem a s s o c i a t e d w i t h p red ry ing
p r i o r t o IQB. The b r i n e sediment v a l u e s w e r e c o n s i s t e n t l y h i g h e r
f o r t h e p r e d r i e d samples. This i s due t o s k i n s p l i t t i n g t h a t occu r s
d u r i n g p red ry ing and subsequen t ly comes o f f i n t h e a g i t a t e d r e t o r t
o p e r a t i o n . Compared t o p i p e b l anch ing , t h e o t h e r steam b lanch ing
systems are q u i t e a c c e p t a b l e .
F i n a l l y , t h e p e r c e n t s p l i t d a t a are p resen ted . Although t h e p e r c e n t
s p l i t i s h i g h e r f o r t h e steam blanched samples , t h i s a p p a r e n t l y w a s
no t d e t r i m e n t a l t o p roduc t q u a l i t y . The b r i n e sediment v a l u e d i d
no t seem t o r e f l e c t t h e s p l i t damage. Greater p e r c e n t s p l i t s i n
steam b lanch ing compared t o water b l anch ing may r e f l e c t t h e d i f -
f e r e n c e i n h e a t i n g rates. With steam b lanch ing t h e t empera tu re
i n c r e a s e s v e r y r a p i d l y r e s u l t i n g i n a r a p i d e x p u l s i o n of t i s s u e
26
Table 7. SUMMARY OF OBJECTIVE EVALUATION OF PEASa
Avg. 32.0
30.2
29.7
29.5
17.5
Blanch- ing
treat- ment
Range 27.9-36.1
24.4-36.8
25.4-31.8
26.4-31.5
10.2-24.9
IQB-6.9
IQB 30 Sec
Deep
Pipe
bed
322.6
318.6
312.7
332.3
301.6
IQB-6.9
I Q B
30 Sec
Deep
Pipe
bed
315.8-328.C
314.4-320.9
309.0-315.5
325.7-337.7
293.4-305.6
IQB-6.9
IQB
30 Sec
Deep
Pipe
bed
6.29
3.82
4.09
3.96
5.30
Can Vacuum (cm. Hg. vacuum)
Months of s torage
5.05-8.18
3.69-3.91
2.97-5.06
2.45-6.12
3.23-8.76
320.4 312.1-324.3 316.4 311.0-323.2
315.8 308.4-320.1
33 7.4 326.6-343.6
!95.1 L 285.7-305.6
5.05-10.36
3.88-4.56 2.81-5.23
3.45-4.37
2.36-5.27
5.41 3.81
3.41
4.07
4.05
326.8
319.2 313.5
337.4
301 .O
Range 20.6-38.4
20.8-41.1
18.3-36.8
23.4-34.5
13.7-28.4
Avg . 31.5
32.0
28.4
28.4
20.8
6
Range 22.1-36.8
22.4-38.4
21.6-31.8
19.8-33.3
16 .O-26.9
7.23
4.23
3.73
3.83
3.59
Drained Weight (g. 1
315.8-337.1
3 11.3 -326.9
307.6-317.5
329.4-345.3
291.1-307.0
5.24-5.57 3.44-4.17
2.98-3.81
3.28-5.06
2.15 - 7.00
320.4 320.1
315.0
334.3
302.5
4.59
3.38
4.80
3.13
3.89
313.0-324.6
311.5-328.0
309.8-318.4
326.6-341.9
299.1-305.9
4.46-4.72
3.33-3.43
1.79-8.30
2.88-3.39
2.16-6.08
a Each average cons i s t s of a t least n ine observat ions.
27
Table 7 Blanch-
ing t reat-
ment
IQB-6.9
IQB 30 Sec
Deep bed
Pipe
:continued). SUMMARY OF OBJECTIVE EVALUATION OF PEASa S p l i t s i n Peas
Avg. Range 38 30-48
28 26-30
36 29-40
40 32-56
18 14-29
Months of Storage 6 9
Avg. Range 35 29-39
41 39-43
36 29-43
33 28-39
22 13-29
Avg. Range 35 26-45
30 24-34
27 21-37
28 19-37
21 14-27
Avg . Range 30 26-35
24 19-30
30 20-40
29 23-34
20 16-25
a Each average c o n s i s t s of a t least n i n e observat ions.
gases . This sudden expansion of gases may f r a c t u r e i n t h e peas
r e s u l t i n g i n eventual s p l i t t i n g . With water blanching, on t h e o t h e r
hand, t h e temperature r i se i s slow enough t o a l low t i s s u e gases t o
d i f f u s e ou t of t h e t i s s u e without developing excessive pressures .
A sunnnary of t h e s u b j e c t i v e eva lua t ion of peas i s given i n Table 8.
From these d a t a it i s concluded t h a t steam blanching r e s u l t e d i n a
canned pea product a t least as good as t h a t produced wi th pipe blanch-
ing. I n those cases where t h e r e w a s a s i g n i f i c a n t d i f f e r e n c e , t h e
steam blanched product w a s g e n e r a l l y prefer red .
I n conclusion, t h e s tudy wi th peas i n d i c a t e s t h a t IQB can be success-
f u l l y used f o r pea blanching wi th a 40% decrease i n l i q u i d waste genera t ion
compared t o pipe blanching. Compared t o deep bed steam blanching,
IQB produced 28% less e f f l u e n t and less product l o s s . IQB wi th pre-
drying i s not recommended due t o s i g n i f i c a n t increases i n b r i n e
sediment. Product q u a l i t y as evaluated by o b j e c t i v e and tas te panel
tests w a s a t least as good fo r IQB as f o r pipe blanching.
CORN BLANCHING
A s u m a r y of t h e corn blanching d a t a is given i n Table 9.
28
Table 8. SUMMARY OF SUBJECTIVE EVALUATION OF PEAS
a IQB-6.25 means IQB wi th a 6.25% weight reduct ion p r i o r t o blanching. IQB-0 means IQB without predrying. 30 Sec means heat only s t age of IQB. Deep bed means deep bed steam blanching. 4 o r 3 r e f e r s t o s ieve s i z e ; Per fec t ion was s ieve s i z e 3 , 4 and 5. A l s means A l s w e e t ; A l a means Alaskan; Perf . means Perfect ion.
w a s canned the same day as the experimental sample. The top number i s the l eve l of s ign i f i cance and the bottom three numbers represent number of judges p re fe r r ing experimental sample, con t ro l and no preference, respec t ive ly . NS means no s i g n i f i c a n t d i f fe rence .
bEach sample w a s compared t o a pipe-blanched, canned con t ro l . The con t ro l
29
Table 9. SUMMARY OF CORN BLANCHING DATAa
E f f luen t genera t ion
(1. /kkp) b Blanching t reatment
IQB-7.5
I Q B - 0
20 Sec
Deep bed
Pipe
Tota l So l ids organic Tota l Product 10s t a s
BOD5 ni t rogen phosphorus y i e l d product (kg/kkg) ( kpylkkg) (kg /kkn ) (% (% )
1.4 2.7
3.0
4.4
4.9
86
125
125
163
730
0.017 0,008 93.1 0.81
0.039 0.020 97 .1 1.61
0.037 0.019 97.4 1.52
0.049 0.028 94.2 2.42
0.089 0.034 -- -- I I I I I
a
bIQB-7.5 means IQB with a 7.5% weight reduct ion p r i o r t o blanching.
Expressed p e r kkg of blanched corn. See Tables A3 and A4 f o r complete data .
IQB-0 means IQB without predrying. 20 Sec means hea t s ec t ion only of I Q B . Deep bed means deep bed steam blanching. Pipe means pipe blanching.
A s wi th pea blanching, a l l of t he steam blanching methods produced
less e f f l u e n t than p i p e blanching. IQB without predrying reduced
e f f l u e n t genera t ion by .83% compared t o p i p e blanching while a 7.5%
weight reduct ion p r i o r t o IQB reduced e f f l u e n t genera t ion by 88%.
The e f f l u e n t generated p e r ton of corn i s considerably less than t h a t
f o r peas because of t he d i f f e r e n c e i n t h e na tu re of t h e su r face of
t he two vegetab les . Cut corn su r faces expose s t a r c h which upon hea t -
ing can absorb water r e s u l t i n g i n less water l o s s . On t h e o the r
hand, t h e BOD5 f o r corn was about t h e same as t h a t f o r peas ind i -
c a t i n g t h a t water t h a t d i d d r a i n of f corn c a r r i e d wi th i t more
s o l i d s .
t h a t f o r peas. This r e f l e c t s t h e f a c t t h a t with corn , t h e blanching
process i s pr imar i ly a wash s t e p t o remove reducing sugars and o the r
components t h a t may con t r ibu te t o brown co lo r development during
thermal processing. In some p l a n t s , corn i s not blanched p r i o r t o
I n p ipe blanching, water usage f o r corn was nea r ly double
1 canning. Weckel e t a l . reported an average of 1043 l . /kkg
30
(250 ga l / ton ) f o r p ipe blanching corn.
blanching r e s u l t e d i n g r e a t e r e f f l u e n t genera t ion than IQB bu t i t
was s t i l l cons iderably less than p ipe blanching.
A s w i t h i peas , deep bed steam
The BOD/N/P r a t i o f o r corn averaged 151 /2 .1 /1 (range 88-237/1 .5-2 .9 /1)
i n d i c a t i n g tha t the waste may b e low i n n i t rogen f o r b i o l o g i c a l
t reatment . From Table A 4 the BOD/COD r a t i o was 0 . 7 8 . Soderquis t
e t a1.l' repor ted a BOD/COD r a t i o of 0.75 f o r corn wastes.
f i g u r e , however, included waste generated a t u n i t opera t ions i n ad-
d i t ion t o blanching . That
With r e spec t t o product y i e l d there a re some i n t e r e s t i n g observa-
t i ons . F i r s t , wi th predrying t h e product y i e l d i s lower than w i t h
IQB without predrying. This r e f l e c t s the f a c t t ha t the corn su r face ,
once dehydrated, is very d i f f i c u l t t o rehydra te and thus t h i s y i e l d
r e f l e c t s l o s s e s of product s o l i d s and l o s s of reabsorbing capac i ty
of t h e sur face . Deep bed steam blanching r e s u l t e d i n g r e a t e r product
loss pr imar i ly through s o l i d s l o s t i n the e f f l u e n t .
Table 10 p resen t s the r e s u l t s of the o b j e c t i v e eva lua t ion on steam
blanched and p ipe blanched corn. As wi th peas , can vacuum f o r the
steam blanched samples i s h ighe r than t h a t f o r t h e pipe blanched
sample. This r e f l e c t s t h e lower water f i l l temperature used i n the
canning p l a n t compared t o t h e labora tory p i l o t p l an t . There was no
s i g n i f i c a n t d i f f e r e n c e i n drained weight between any of t h e samples.
A s u m a r y of the s u b j e c t i v e eva lua t ion of corn i s given i n Table 11.
There appears t o be a s i g n i f i c a n t d i f f e r e n c e between steam blanched
and p ipe blanched samples bu t the preference i s not cons i s t en t . It
was observed tha t the steam blanched samples were darker i n c o l o r
than the p ipe blanched samples a t t e s t i n g t o the f a c t t h a t the blanch
s t e p is p r imar i ly a wash s t e p f o r corn. This da rke r c o l o r , however,
d id n o t man i fe s t i t s e l f i n consumer preference meaning tha t perhaps
31
blanching does not have t o serve as a wash s t e p i f the consumer cannot
de t ec t t he co lor d i f fe rence .
Avg . 26.9
31.8
28.2
26.4
23.6
Table 10. SUMMARY OF OBJECTIVE EVALUATION OF CORNa
Range
21.6-30.7
29.0-35.1
23.6-36.6
22.6-31.8
18.5-28.7
Blanch- ing
treat- men t
IQB - 7.5
IQB 20 Sec
Deep bec
Contro 1
IQB- 7.5
IQB
20 Sec
Deep bec
Con t r o 1
Can Vacuum (cm. Hg. vacuum)
Months of Storage
327.7
324.6
325.5
331.7
327.2
326.9-294.1
322.6-327.7
320.9-330.9
330.3-332.8
310.4-343.1
3
Avg . 27.9
32.5
32.3
31.0
18.5
b
6 9 I
Avg . 21.8
26.7
23.6
20.6
17.5
Range
15.2-27.4
20.8-34.8
19.1-31.8
14.5-31.2
16.5-19.6
Drained Weight
328.0b
317.8
317.2
326.9
304.4
326.9
318.4
315.8
327.7
324.6
321.8-330.3
315.8-320.1
314.7-317.2
322.6-330.3
315.8-339.4
Avg . 23.1
27.7
27.7
24.6
22.6
322.9
323.5
321.2
330.3
322.1
Range
21.6-25.4
25.4-32 .O
22.6-34.3
51.8-31.8
17.8-26.2
317.8-329.4
316.1-328.3
320.6-322.1
328.3-332.3
313.5-337.1
a
bOnly one series of samples w a s evaluated a f t e r th ree months' s torage. Each average cons i s t s of a t l e a s t nine observat ions.
In conclusion, IQB and deep bed steam blanching both r e s u l t i n
d r a s t i c reduct ions of e f f l u e n t generat ion i n corn blanching. How-
ever , i n both cases a darker product r e su l t ed a f t e r r e t o r t i n g . To
maintain a b r igh t golden yellow co lo r , corn would have t o be thor-
oughly washed p r i o r t o steam blanching.
de fea t s the purpose of steam blanching s ince the wash s t e p would
c r e a t e another high volume-low load e f f l u e n t steam. Therefore, the
This wash s t e p , i n tu rn ,
32
Table 11. SUMMARY OF SUBJECTIVE EVALUATION OF CORN
Blanching t rea tmen ta
IQB-7.5
IQB-0
20 Sec
Storage t i m e (months)b 1 3 6 9
1% 1% 0.1%
5% 0.1% 5% 3-8-5 0-11-3 NS 3-4-6
1% 1% NS 9-4-1 NS 2-9-4 5% 0.1%
4-10-4 4-7-3 2-17-4 NS
Deep bed I 3-8-3
I 2-12-7 I 6-6-5 I I ’ 1%
-- IQB-7.5 I 8-13-1
6-9-1 I NS I NS
IQB - 0 I NS
I I I I - - 3-7-2 10-6-2 1 %
20 Sec NS
NS 7-3-6 - -
Deep bed NS 7-9-2 I NS -- IQB- 7.5 I 8-5-4
advantage of producing a b r i g h t yellow corn must be weighed a g a i n s t
t h e disadvantage of c r e a t i n g an e f f l u e n t stream and t h e c o s t of i t s
subsequent t reatment . Since blanching of corn must be done when
corn is packed i n t o No. 10 cans, t h e r e i s s t i l l a use f o r steam
blanching . 33
I 10-6-5 I 18-3-4 -- IQB-0
20 Sec
Deep Bed
10-8-0 -- 9-7-2 5-16-4 0.1% 0.1%
18-3-1 -- NS 16-3-3 0.1% 0.1% 0.1%
17-2-0 -- 11-7-2 11-5-3
LIMA BEANS
Lima bean blanching r e s u l t s are summarized i n Table 12.
To ta l o rganic n i t rogen (kg Ikkp )
0.02
0.12
0.06
0.17
0.02
Table 12. SUMMARY OF LIMA BEAN BLANCHING DATAa
Tota l Product phosphorus y i e l d
(kg Ikkg ) (%)
0.004 97.5
0.02 93.4
0.015 96.7
0.04 88.7 0.01 --
Blanching t reatmentb
IQB-5 .O
IQB - 0
20 Sec
Deep bed
Pipe
Ef f luen t genera t ion
(l . /kkg)
67
171
133
238
82 1
BOD^ 5 kg 1 kkg )
0.35
1.7
2.4
3.5
0.65 I I
Sol ids l o s t as product
(% )
0.24
0.86
0.54
1.38 --
a Expressed p e r kkg of blanched product. See Tables A5 and A6 f o r complete da t a .
bIQB-5.0 means IQB wi th a 5.0% weight reduct ion p r i o r t o blanching. IQB-0 means IQB without predrying. 20 Sec means hea t s e c t i o n only of I Q B . Deep bed means deep bed steam blanching. Pipe means p ipe blanching.
Resul t s wi th lima beans p a r a l l e l those obtained wi th peas and corn.
The e f f l u e n t genera t ion va lues a r e s i m i l a r t o those repor ted f o r
corn i n Table 9 and r e f l e c t s t h e water hold ing capac i ty of t h e s u r -
f ace of the lima bean. I n lima bean processing t h e blanch s t e p
serves t o p a r t i a l l y rehydra te the dry l i m a bean seeds.
The p ipe blanching method produced 821 l . /kg (197 g a l l t o n ) compared
t o only 171 l . /kg (41 ga l / t on ) f o r IQB; IQB reduced e f f l u e n t by 79%.
Predrying reduced t h e e f f l u e n t t o only 8% of t h a t f o r pipe blanching.
The BODINIP r a t i o averaged 9714.811 (range 32-205/1.1-7.811) i n d i c a t i n g
t h a t lima bean blancher e f f l u e n t has an adequate n u t r i e n t balance f o r
34
b i o l o g i c a l waste t reatment . The BOD/COD r a t i o was 0.76 (ca lcu la ted
from Table A6). Product y i e l d f i g u r e s i n d i c a t e t h a t l i m a beans re-
hydra te r e a d i l y a f t e r t h e predrying s t e p s i n c e t h e y i e l d i s g r e a t e r
than t h a t f o r t h e o t h e r steam blanching methods. The d i f f e r e n c e
between t h e y i e l d values f o r IQB-0 and 20 sec r e f l e c t product l o s s
and l i q u i d l o s s i n t h e hold s e c t i o n dur ing IQB. The only d i f f e r e n c e
between t h e s e two runs i s t h e f a c t t h a t t h e 20 sec experiment d i d
not include t h e hold s e c t i o n . The l i q u i d l o s s occurr ing i n the hold
s e c t i o n i s a l s o r e f l e c t e d i n t h e h igher e f f l u e n t genera t ion value
reported f o r IQB-0 compared t o 20 sec. Deep bed steam blanching
r e s u l t e d i n t h e lowest y i e l d and i s p a r t i a l l y accounted f o r i n the
s o l i d s l o s t . The o t h e r l o s s i s accounted f o r i n t h e decreased water
holding capac i ty of t h e s u r f a c e due t o a h igher mass average t e m -
p e r a t u r e of t h e deep bed blanched lima beans.
Resul t s of t h e o b j e c t i v e eva lua t ion of l i m a beans i s given i n Table
13. It can be seen t h a t can vacuum of a l l of t h e steam blanched
samples i s considerably lower than t h a t f o r pipe blanched, canned
product. This may have been due i n p a r t t o can o v e r f i l l i n t h e
experimental samples. Notice t h a t most of t h e drained weights are
g r e a t e r f o r t h e experimental ly blanched samples i n d i c a t i n g t h a t t h e
can w a s o v e r f i l l e d . Upon r e t o r t i n g t h e lima bean absorbs water and
expands. This can r e s u l t i n decreased can vacuum. Thus, t h e lower
can vacuum f o r t h e steam blanched samples does n o t n e c e s s a r i l y re-
f l e c t poor t i s s u e gas removal. The somewhat h igher (8-10%) drained
weights f o r t he s t e a m blanched samples could be cor rec ted by
f i l l i n g a t approximately 227-241 g.(8-8.5 ounces) r a t h e r than t h e
c u r r e n t 256 g. (9.0 ounces) f i l l weight. Proper drained weight
would then be achieved following r e t o r t i n g and can vacuum would
probably be higher .
Although i t w a s not
suspended s o l i d s i n
recorded, t h e r e appeared
the IQB predried sample.
35
t o be more sk ins and
This w a s presumably
Table 13. SUMMARY OF OBJECTIVE EVALUATION OF LIMA BEANS
381.4-413.6
299.6-315.0
277.8-315.8
338.7-343.5
Blanch- ing
t reat- ment
IQB - 5.0
IQB
20 Sec
Deep
Pipe
bed
IQB-5.0
IQB
20 Sec
Deep bed
Pipe
368.3
317.8
303.6
341.1
Can Vacuum (cm. Hg. vacuum)
Months of Storage
(g.1 362.3-373.2 386.0 372.8-394.9
295.1-340.2 338.5 296.8-380.3
283.4-323.5 298.2 279.7-317.5
335.0-343.9 341.1 336.9-345.3
Avg . 15.0
15.7
12.7
12.4
400.4
334.3
301.3
344.2
1
11.4-21.6 9.7-21.6
12.2-13 .O 6 4-20.3
Range
298.2-317.2 05.6
29.7 28.7-31.2 I
293.7-311.8
1
395.3
307.3
296.8
341.7
324.0
a Each average
- Avg . 17.0
17.8
17.0
16.3
30.5
298.2-364.9 07.9 2
'1
Range 15.2-19.1
13.5-21.8
14.5- 19.6 14.0-19.1
29.7-31.8
Avg . 17.0
18.8
17.8
13.7
28.7
6 Range
10.2-20.3 14.7-22.6
14.2-21.1
10.2-17.9
28.2-29.2
15.7
14.5
15.2-16.3
8.9-17.8
27.4 26.7-28.4 . I Drained Weight
cons i s t s of a t least three observat ions.
374.5-414.7
299.9-368.6
278.6-324.0
338.0-349.7
306.7-319.8
due t o the rupture of sk ins during drying which were released during
t h e ag i t a t ed cook. On t h i s b a s i s i t i s doubtful i f I Q B w i t h pre-
drying i s an acceptable process.
Subject ive eva lua t ion of lima beans i s presented i n Table 14. There
w a s no clear t rend i n preference f o r e i the r steam blanched o r pipe
blanched product. This probably r e f l e c t s the f a c t t ha t people
usua l ly do no t have a s p e c i f i c idea of what good l i m a beans are
supposed t o taste o r look l i k e . The conclusion can be made tha t
there i s probably a d i f f e rence bu t t ha t i t w a s no t a s t r i k i n g enough
36
Table 14. SUMMARY OF SUBJECTIVE EVALUATION OF LIMA BEANS
B l anch ing trea tmen ta
S to rage Timeb (months) 1 3 6 9
0.1% 0.1% I 1% I IQB-5.0 I 9-6-1
0.1%
Deep Bed I NS I NS I 8-4-9 I 5-4-11 0.1%
8-6-3 8-5-4 NS 0.1% 0.1%
IQB-0 NS 6-8-5 NS NS 0.1% 0.1% 0.1%
d i f f e r e n c e t o a l low development of a p re fe rence .
f i c a t i o n f o r d i s c a r d i n g any of t h e steam b lanch ing methods based on
s u b j e c t i v e e v a l u a t i o n .
There is no j u s t i -
I n c o n c l u s i o n , IQB wi thou t p red ry ing can be s u c c e s s f u l l y a p p l i e d t o
lima beans. Adjustment must be made i n f i l l weight t o a r r i v e a t t h e
c o r r e c t d ra ined weight s i n c e t h e r e i s more r e h y d r a t i o n i n the can
w i t h IQB blanched beans. Predry ing r e s u l t s i n a g r e a t e r r e d u c t i o n
i n e f f l u e n t g e n e r a t i o n ; however, p red ry ing a d v e r s e l y a f f e c t s product
q u a l i t y due t o s k i n s p l i t t i n g .
GREEN BEAN BLANCHING
Table 15 p resen t s a summary of t h e green bean blanching r e s u l t s ,
Blanching t reatment
IQB - 0
Deep bed
Pipe
Table 15. SUMMARY OF GREEN BEAN BLANCHING DATAa
To ta l E f f luen t organic
genera t ion BOD n i t rogen (l . /kkp) (kg/kl?g) (kg/kkg)
163 1.0 0.03
125 0.55 0.015
334 -- --
Tota l phosphorus
0.008
0.005
(kg /kkp)
--
Product y i e l d
(%)
94.0
97.3 --
Sol ids l o s t as product
(%I 1.16
0.89 --
a Expressed p e r kkg of blanched product. See Tables A7 and A 8 f o r complete da ta . A l l p ipe blanching ana lyses were d iscarded due t o inappropr ia te sample s torage .
Deep bed means deep bed steam blanching. Pipe means p ipe blanching.
bIQB-O means IQB without predrying.
I n green bean blanching, steam blanching r e s u l t e d i n a 51-63%
decrease i n e f f l u e n t genera t ion compared t o p ipe blanching. With
green beans there w a s a d i f f e r e n t t rend than with the previous ly
blanched products . I n pea, corn o r l i m a bean blanching the deep
bed steam blanching t reatment always r e s u l t e d i n a g r e a t e r genera-
t i o n of e f f l u e n t . With green beans the oppos i te i s t r u e ; tha t i s ,
deep bed blanching r e s u l t e d i n less e f f l u e n t than IQB-0. This re-
f l e c t s the p e c u l i a r na tu re of green bean blanching i n tha t the
maximum temperature reached was 79 C (175 F) . I n green bean blanch-
ing , t h e bean must reach a t least 63 C (145 F) bu t must no t exceed
82 C (180 F) i n o rde r t o ac t iva te the enzyme p e c t i n methyl esterase (PME).
This enzyme, once a c t i v a t e d , w i l l c l eave methoxy groups from pec t in
i n t h e ou te r l a y e r a l lowing calcium-pectin i n t e r a c t i o n and conse-
quent ly no sloughing. In both deep bed and IQB the mass average
temperature was between 77 C (170 F) and 82 C (180 F). Consequently
38
t h e r e was no d i f f e r e n c e i n t h e amount of steam r e q u i r e d f o r h e a t i n g .
A l so , s i n c e t h e r e was no d i f f e r e n c e i n t empera tu re bo th t r e a t m e n t s
should have r e s u l t e d i n e q u i v a l e n t s u r f a c e wa te r -ho ld ing c a p a c i t y .
However, i n deep bed steam b lanch ing t h e r e was a g r e a t e r water-
h o l d i n g c a p a c i t y i n t h e bed i t s e l f r e s u l t i n g i n less e f f l u e n t d r a i n -
i ng from t h e p rocess .
Ral ls e t a1.8 r e p o r t e d e f f l u e n t g e n e r a t i o n of 196 l . / kkg (47 g a l / t o n )
f o r steam b lanch ing and 7080 l . /kkg (1700 g a l / t o n ) f o r water b lanch-
i n g .
Deep Bed r e p o r t e d h e r e and, i n t h e case of steam b l a n c h i n g , may b e
due t o b l anch ing i n 100 C steam r a t h e r t han a steam-air m i x t u r e a t
79-82 C (175-180 F).
b l anch ing system may r e f l e c t t h e f a c t t h a t ba t ch - type exper iments
were conducted and perhaps much more p roduc t could have been proc-
essed b e f o r e t h e b l a n c h e r water had t o be changed. A l so , f eed and
b l eed systems may be more e f f i c i e n t from a waste g e n e r a t i o n s t a n d -
p o i n t t han s t r a i g h t b a t c h systems. S o d e r q u i s t e t a1.l' r e p o r t e d
446 l . / k k g (107 g a l / t o n ) f o r a r o t a r y steam b lanche r . This compares
q u i t e f a v o r a b l y t o t h e 334 l . / kkg (80 g a l / t o n ) r e p o r t e d h e r e f o r
p i p e b l anch ing .
Both of these v a l u e s are c o n s i d e r a b l y h i g h e r t h a n t h e IQB-0 and
The exceed ing ly h i g h v a l u e f o r t h e water
The BOD/N/P r a t i o ' f o r g reen bean b l a n c h e r e f f l u e n t w a s 114/3 .8 /1
(range 105-129/2.7-7.4/1)indicating t h a t t h e l i q u i d waste stream
probably c o n t a i n s adequa te n i t r o g e n and phosphorus f o r b i o l o g i c a l
t r ea tmen t .
f o r t h e r o t a r y b l anch ing o p e r a t i o n and a BOD/COD r a t i o of 0.53.
S o d e r q u i s t e t a1.l' r e p o r t e d a BOD/N/P r a t i o of 109 /6 /1
5 P red ry ing was n o t a t t empted i n t h i s s t u d y s i n c e r e s u l t s i n 1971
had shown t h a t even w i t h a 6% weight r e d u c t i o n s k i n r u p t u r e was
seve re . With p r e d r y i n g t o less t h a n 6%, t h e s a v i n g s i n e f f l u e n t
38
g e n e r a t i o n would n o t j u s t i f y t h e c o s t of p red ry ing . T h e r e f o r e ,
p red ry ing p r i o r t o I Q B i s no t recommended f o r green beans.
Table 16 summarizes t h e o b j e c t i v e e v a l u a t i o n s performed on g reen
beans. Can vacuum was n o t i c e a b l y lower f o r t h e two steam blanched
samples compared t o p i p e blanched samples. This w a s p robably due
t o b r i n e o v e r f i l l i n t h e e x p e r i m e n t a l l y b lanched samples s i n c e t h e can
vacuum v a l u e s do n o t f o l l o w any p a t t e r n w i t h s t o r a g e t i m e . I f t h e
poor can vacuum had been due t o p re sence of a i r ce l l s i n t h e g reen
bean t i s s u e , t h e can vacuum v a l u e s would have dec reased upon s t o r a g e .
In s t ead t h e can vacuum a c t u a l l y i n c r e a s e d upon s t o r a g e f o r t h e IQB
sample and f l u c t u a t e d f o r t h e deep bed sample. There was no s i g -
n i f i c a n t d i f f e r e n c e i n d r a i n e d weight between any of t h e t r e a t m e n t s .
For s lough and p e r c e n t s p l i t s , however, IQB w a s d e f i n i t e l y s u p e r i o r
t o bo th deep bed steam b lanch ing and p i p e b l anch ing . These low
v a l u e s are i n d i c a t i v e t h a t PME had been a c t i v a t e d . With deep bed
steam b lanch ing t h e s u r f a c e t empera tu re of t h e t i s s u e may have been
over 180 F f o r s h o r t p e r i o d s of time r e s u l t i n g i n PME i n a c t i v a t i o n .
Deep bed steam b lanch ing compares f a v o r a b l y t o p i p e b l anch ing .
S u b j e c t i v e e v a l u a t i o n of green beans i s sumnarized i n Table 1 7 .
From t h e s e d a t a it is a p p a r e n t t h a t t h e r e i s no real p r e f e r e n c e f o r
product blanched i n steam o r h o t water. Even though t h e o b j e c t i v e
tes ts i n d i c a t e d c o n s i d e r a b l y less s lough and p e r c e n t s p l i t s f o r I Q B ,
t h e tas te panel could n o t p i c k o u t t h a t c h a r a c t e r i s t i c as a b a s i s
f o r e s t a b l i s h i n g p r e f e r e n c e . Th i s p o i n t s o u t t h e f a l l a c y of u s i n g
on ly o b j e c t i v e o r s u b j e c t i v e tes ts t o e v a l u a t e i n n o v a t i v e o r new
p rocess ing t echn iques .
I n c o n c l u s i o n , IQB and deep bed steam b lanch ing can be used t o
b l anch g reen beans p r i o r t o canning . A steam-air m i x t u r e a t 77-82 C
(170-180 F) i s r e q u i r e d t o a c t i v a t e €'ME. IQB produced 51 p e r c e n t
40
Table 16. SUMMARY OF OBJECTIVE EVALUATION OF GREEN BEANSa
Blanching t reatment
I Q B
Deep Bed
Pipe
Months of S to rage 1 3 6 9
Aver. Range Aver. Range Aver. Range Aver. Range
1 .0 0-5.1 0.0 0-0 3 .1 0-7.6 4 . 1 0-8.9
0.8 0-1.3 6.9 2.5-12.7 1 .5 0-7.6 8.9 5.1-14.0
17.0 15.2-17.8 16.3 12.7-19.1 17.0 16.5-17.8 17.0 16.5-19.1
I Q B
P ipe
I Q B Deep Bed
P ipe
Drained Weight
5.0 5.0-5.0 2.5 0-5.0 5.0 5.0-5.0 15.0 10.0-20.0
32.5 30.0-35.0 30.0 25.0-35.0 35.0 30.0-40.0 22.5 20.0-25.0
52.5 35.0-70.0 55.0 50.0-60.0 22.5 20.0-25.0 55.0 55.0-55.0
I Q B Deep Bed 12.0-15.0
Pipe 6.5-9.0
Slough ( X )
8 .0 8.0-8.0 7.0 7.0-7.0 10.0 9.0-11.0
16.0 14.0-18.0 16.0 15.0-17.0 15.0 15.0-15.0
16.0 16.0-16.0 11.0 9.0-13.0 15.0 14.0-16.0
S p l i t s
less e f f l u e n t than p ipe blanching and r e s u l t e d i n considerably less
slough and pe rcen t s p l i t s . Organo lep t i ca l ly , t h e steam blanched
products were q u i t e accep tab le .
41
Table 17. SUMMARY OF SUBJECTIVE EVALUATION OF GREEN BEANS
Blanching t reatmenta
IQB - 0
Deep bed
s t o r a g e t i m e D (months )
1 3 6 9
0.1% 5% 5% 10-5-5 6-3-4 NS 6-6-4
1% 1% 1% NS 5-6-3 5-8-3 5-6-6
POTATO BLANCHING
T o t a l E f f l u e n t o rgan ic
Blanching gene ra t ion BOD5 n i t r o g e n t reatmentb , (1. /kkp) (kg/kkg) , ( kg/kkp)
IQB-6.9 100 0.5 0.03
I Q B - 0 1 7 1 0.75 0.05
Deep bed 167 0.65 0.065
Po ta to blanching d a t a are summarized i n Table 18.
Table 18. SUMMARY OF POTATO BLANCHING DATAa
S o l i d s T o t a l Product l o s t as
phosphorus y i e l d product (kg /kkg ) (%) (%)
0.0085 93.1 0.43
0.012 93.4 0.60
0.017 93.8 0.61
Expressed p e r kkg of blanched product. See Tables A9 and A10 f o r complete da t a .
bIQB-6.9 means IQB wi th a 6.9% weight r e d u c t i o n p r i o r t o blanching. IQB-0 means IQB wi thou t predrying. Deep bed means deep bed steam blanching.
a
4 2
Since p o t a t o e s are n o t normal ly blanched fo l lowing s l i c i n g o r d i c i n g
t h e r e i s no water b l anch ing method t o which t o compare t h e steam
b lanch ing method. However, t h e s e exper iments were inc luded f o r
t hose p r o c e s s o r s who b o t h can and f r e e z e o r dehydra t e p o t a t o e s .
P r i o r t o f r e e z i n g o r d e h y d r a t i o n , p o t a t o e s may h e b ianched . The
d a t a f o r e f f l u e n t g e n e r a t i o n are q u i t e similar t o t h o s e p re sen ted
f o r c o r n and r e f l e c t t h e wa te r -ho ld ing c a p a c i t y of t h e c u t p o t a t o
s u r f a c e . The BOD5 gene ra t ed p e r t o n of product i s q u i t e low sug-
g e s t i n g t h a t most of t h e f r e e s u r f a c e c e l l u l a r j u i c e s were washed
o f f t h e p o t a t o p r i o r t o b l anch ing . Th i s prewashing was accomplished
by t r a n s p o r t i n g the p o t a t o e s t o t h e l a b o r a t o r y under water and then
washing them a g a i n i n the p i l o t p l a n t . Deep bed and IQB-0 r e s u l t e d
i n n e a r l y t h e same e f f l u e n t g e n e r a t i o n . This w a s due t o t h e f a c t
t h a t pe rox idase i n a c t i v a t i o n i n t h e p o t a t o s l i ce r e q u i r e d a h e a t
time of 60 seconds r e s u l t i n g i n a m a s s ave rage t empera tu re n e a r 93 C
(200 F ) . Thus, compared t o deep bed steam b lanch ing where t h e mass
ave rage tempera ture w a s between 93-99 C (200-210 F ) , t h e r e would be
l i t t l e d i f f e r e n c e i n t h e t o t a l steam condensed. Consequent ly , t h e r e
w a s l i t t l e d i f f e r e n c e between deep bed and IQB. The h e a t o n l y sec-
t i o n of t h e IQB p rocess was n o t r u n w i t h p o t a t o e s o r any of t h e r o o t
c rops .
that IQB-0 and t h e hea t -on ly r u n s d i d n o t d i f f e r s i g n i f i c a n t l y i n
e f f l u e n t g e n e r a t i o n s i n c e l i t t l e e f f l u e n t w a s released i n t h e ho ld
s e c t i o n . A l s o , f o r t h e r o o t c r o p s b l anch ing is u s u a l l y r e q u i r e d
p r i o r t o f r e e z i n g t o p a r t i a l l y cook t h e product .
cumstances t h e hea t -on ly method would probably n o t b e adequa te as a
b l anch ing t echn ique .
This was n o t run s i n c e i t had been observed i n ea r l i e r t r i a l s
Under t h e s e c i r -
The BOD/N/P r a t i o f o r p o t a t o b l a n c h e r e f f l u e n t w a s 57/3.9/1 ( range
37-66/3.6-4.2/1) i n d i c a t i n g t h a t adeuqate n u t r i e n t s are available for
b i o l o g i c a l t r ea tmen t . The BOD/COD r a t i o averaged 0.90.
43
Objec t ive a n a l y s i s of t h e po ta to blanching t r ia l s i s summarized i n
Table 19 . The lower can vacuum f o r t h e steam blanched samples i s
a t t r i b u t e d t o o v e r f i l l r a t h e r than incomplete t i s s u e gas removal.
Table 19. SUMMARY OF OBJECTIVE EVALUATION OF POTATOESa
B 1 anc h ing t reatment
IQB-6.9
IQB Deep Bed
Control
(cm. Hg. vacuum) Months of S torage
1 3 6 9 Aver. Range Aver. Range Aver. Range Aver. Range
12.2 8.9-16.5 7.9 5.1-10.2 10.9 7.6-15.2 12.2 8.9-16.5
12.4 10.2-19.1 7.8 5.1-11.4 12.7 7.6-17.8 10.9 7.6-15.2 9.4 3.8-11.4 8.6 6.4-12.7 11.7 10.2-17.8 16.0 14.0-19.1
22.4 16.5-27.9 17.3 14.0-25.4 18.5 12.7-24.1 20.6 15.2-25.4
Table 20 presen t s a summary o f t h e s u b j e c t i v e eva lua t ions on pota toes .
The IQB predr ied b lanching technique w a s no t accep tab le due t o darkening
of t he po ta to s u r f a c e du r ing a i r d ry ing . This i s evidenced by the low
preference f o r t h e IQB-predried sample. With IQB and deep bed steam
IQB-6.9 334.6 332.2-335.0 330.6 326.1-333.8 338.2 331.4-342.9 343.6 335.0-352.9 330.9 320.7-335.7 336.3 328.8-340.4
Deep Bed 345.1 334.4-352.8 244.9 328.4-356.2 340.5 328.3-358.1 Control 312.4 285.7-335.4 286.6 274.2-301.3 311.3 292.6-350.8 A
44
333.1 328.6-336.8 336.0 325.3-343.9 337.4 330.4-343.7 308.4 283.1-357.1
Table 20. SUMMARY OF SUBJECTIVE EVALUATION OF POTATOES
B l a n c h i n g s t o r a g e t imeb
(months ) t r e a t m e n t a
IQB-6.9
1 3 6
5% 0.1% 1% 2-9-3 4-6-8 5-5-6
9
IQB-0
Deep bed
NS
NS NS NS
0.1% 4-9-3 NS NS
1% 4-8-5
1% 8-5-2
a IQB-6.9 means I Q B w i t h a 6.9% weight r e d u c t i o n p r i o r t o b l anch ing . IQB-0 means I Q B w i t h o u t p red ry ing . Deep bed means deep bed steam blanching .
Each sample was compared t o a c o n t r o l s ample . The c o n t r o l w a s canned t h e same day as t h e expe r imen ta l sample . The t o p number i s t h e l e v e l of s i g n i f i c a n c e and t h e bottom t h r e e numbers r e p r e s e n t number of judges p r e f e r r i n g expe r imen ta l sample, c o n t r o l and no p r e f e r e n c e , r e s p e c t i v e l y . NS means no s i g n i f i c a n t d i f f e r e n c e .
b
b l anch ing t h e r e w a s ve ry l i t t l e d i f f e r e n c e i n samples as evidenced
by t h e tas te pane l r e s u l t s .
pared i n l a r g e q u a n t i t y b a t c h e s ( f o r example, a can f u l l ) , t h e steam
blanched p roduc t appeared somewhat d a r k e r t han t h e p i p e b lanched .
This was b e l i e v e d due t o da rken ing of t h e p o t a t o e s i n t r a n s p o r t t o
t h e l a b o r a t o r y .
r e a d i l y a p p a r e n t s i n c e t h e taste pane l showed no p r e f e r e n c e .
However, when t h e p roduc t s were com-
The importance of t h i s s l i g h t da rken ing is n o t
I n c o n c l u s i o n , IQB wi thou t p red ry ing can be s u c c e s s f u l l y a p p l i e d t o
p o t a t o b l anch ing . A t t h e load ing rates used i n t h i s s t u d y , I Q B
o f f e r e d l i t t l e advantage ove r deep bed steam b lanch ing . However,
a t g r e a t e r l oad ing ra tes I Q B would be expected t o produce s i g -
n i f i c a n t l y less e f f l u e n t t h a n deep bed steam b lanch ing . The IQB
blanched product was e q u i v a l e n t t o c o n v e n t i o n a l l y canned product .
P red ry ing i s n o t recommended due t o s u r f a c e da rken ing d u r i n g a i r
d ehyd ra t ion. 45
BEET BLANCHING
The b e e t b l anch ing d a t a are summarized i n Table 21.
T o t a l E f f l u e n t o r g a n i c T o t a l Product
g e n e r a t i o n BOD5 n i t r o g e n phosphorus y i e l d (1. /kkg) (kg/kkg) ( kq /kkg ) (kg /kkg ) (%)
196 5.75 0.11 0.0285 86.3
229 4.95 0.085 0.022 89.4
225 4.8 0.11 0.0305 88.9
Table 21. SUMMARY OF BEET B U N C H I N G DATAa
S o l i d s l o s t as p roduc t
(%)
5.21
4.02
5.26
Blanching t r ea tmen tb
IQB-5.6
IQB-0
Deep bed
a Expressed complete d
1 l i
bIQB-5.6 means IQB w i t h a 5.6% weight r e d u c t i o n p r i o r t o b l anch ing . IQB-0 means I Q B w i t h o u t p red ry ing . Deep bed means deep bed steam b lanch ing .
A s w i t h p o t a t o e s s l i c e d b e e t s are n o t normal ly blanched p r i o r t o
canning and, t h e r e f o r e , t h e r e i s no c o n v e n t i o n a l b l anch ing o p e r a t i o n
f o r comparison. Gene ra l ly i t i s assumed t h a t b l anch ing w i l l be
accomplished i n t h e steam t r e a t m e n t a n d / o r h o t water p rocess j u s t
p r i o r t o p e e l i n g . F r e q u e n t l y , however, t h e c e n t e r t empera tu re of
t h e b e e t i s n o t i n t h e range t o i n a c t i v a t e enzymes. When t h i s i s
t h e c a s e , d e l a y i n g e t t i n g t h e s l i c e d o r d i ced b e e t s i n t h e can may
r e s u l t i n darkening of t h e b e e t , This i s u n d e s i r a b l e . The b e e t
s l ices t h a t were ob ta ined from t h e canning p l a n t f o r t h i s s t u d y had
p o s i t i v e pe rox idase a c t i v i t y p r i o r t o t h e steam b lanch ing r u n s .
The d a t a i n Table 21 reveal s e v e r a l impor tan t c h a r a c t e r i s t i c s of
b e e t b l anch ing . F i r s t , t h e e f f l u e n t g e n e r a t i o n v a l u e s are n e a r l y
t h e same as t h o s e r e p o r t e d f o r pea b l anch ing . The h i g h e f f l u e n t
g e n e r a t i o n v a l u e s , however, are t h e r e s u l t of c e l l u l a r l o s s e s r a t h e r
46
than i n a b i l i t y o f . t h e bee t su r f ace t o hold su r face moisture. The
BOD values a r e t h e h i g h e s t of those reported i n t h i s s tudy as are
the " so l id s l o s t as product" f i g u r e s . This i n d i c a t e s t h a t bee t
t i s sue i s very s u s c e p t i b l e t o h e a t damage.
of blanching w i l l r e s u l t i n high s o l i d s l o s s from the t i s s u e . For
comparison, Ralls e t a1.8 reported 317 l . / kg (76 g a l / t o n ) f o r steam
blanching of b e e t s and 5550 l . /kkg (1330 g a l / t o n ) f o r water blanch-
ing. Comparing IQB t o those r e s u l t s , IQB would reduce l i q u i d waste genera-
t i o n by about 28%. A s wi th green beans, t he 5550 l./kkg (1330 g a l /
ton) i s probably unduly l a rge s i n c e presumably more product could
have been run through the blancher , lowering t h e e f f l u e n t value.
Predrying t h e b e e t s u r f a c e p r i o r t o IQB r e s u l t e d i n a f u r t h e r d e -
c r ease i n e f f l u e n t generat ion; however, during a i r drying some
darkening d i d occur. This w a s undes i r ab le and r e s u l t e d i n a low
preference f o r t h a t t reatment .
Consequently, any method
The BOD/N/P r a t i o averaged 208/3.8/1 (range 158-292/3.6-4.0/1) i nd i -
c a t i n g t h a t bee t blancher water maybe low i n n i t rogen f o r b i o l o g i c a l
waste t reatment .
than t h e 0.87 reported by Soderquis t e t a l .
The BOD/COD r a t i o averaged 0.97 s l i g h t l y higher 10 .
Objective eva lua t ion of b e e t s r e s u l t e d i n t h e d a t a summarized i n
Table 22. The can vacuum was lower f o r a l l t h e steam blanched
samples compared t o c o n t r o l . Examination of the drained weight
d a t a shows t h a t t he experimental samples contained a t least 56 g.
(two ounces) more than t h e c o n t r o l and were o v e r f i l l e d . Instead of
using the 312 g. (11 ounce) f i l l weight, t h e f i l l weight could have
been 256 g. (9 ounces). The drained weight d a t a show t h a t i n t h e
can the bee t w i l l lose t i s s u e j u i c e s during t h e . r e t o r t i n g ope ra t ion
and consequently the drained weight i s less than t h e f i l l weight.
By blanching p r i o r t o canning t h e j u i c e is loSL before the bee t i s
p u t i n t h e can. From a canner 's point of view i t i s b e s t not t o
47
blanch p r i o r t o canning s i n c e then he has t o c l e a n up t h e b lancher
e f f l u e n t . Without b lanching , t h e e f f l u e n t ends up i n t h e can and
even tua l ly ends up i n t h e k i t c h e n where t h e housewife d i sposes of
i t . On the o t h e r hand, i f t h e canner has d i f f i c u l t y making dra ined
weight on canned b e e t s , then b lanching p r i o r t o canning w i l l a l low
him t o more n e a r l y match f i l l weight t o d r a i n weight.
Table 22. SUMMARY OF OBJECTIVE EVALUATION OF BEETSa
IQB-5.6
I Q B Deep Bed
Control
10.4 8.9-11.4 7.9 5.1-15.2 8.6 5.1-10.2 5.8 5.1-8.9 11.9 7.6-15.2 6.4 5.1-7.6 4.6 2.5-5.1 7.6 5.1-10.2 10.4 6.4-12.7 5.1 5.1-5.1 6.1 2.5-10.2 12.4 7.6-15.2 22.9 16.5-33.0 16.3 10.2-22.9 15.0 11.4-19.1 16.8 10.2-20.3
-~
Drained Weight (d
IQB-5.6
I Q B
Deep Bed
Control
330.3 327.2-331.4 329.7 326.6-330.8 329.2 327.6-330.8 332.8 329.8-334.9 327.5 323.4-332.3 325.7 320.3-328.2 332.3 328.3-338.0 329.4 323.1-337.8 326.3 323.8-327.0 329.2 320.8-332.7 336.3 328.3-340.0 332.8 325.1-339.1 265.5 249.7-281.0 262.1 240.5-279.0 250.2 218.0-266.5 259.6 244.1-288.5
48
Table 23. SUMMARY OF SUBJECTIVE EVALUATION OF BEETS
Blanching t rea tmenta
IQB-5.6
IQB
Deep bed
1 1%
4-7-4
NS
1% 6-6-4
S t o r a g e t i m e " (months )
NS
NS
NS
1% 3-7-4
NS
0.1% 2-15-1
0.1% 4-7-11
NS
NS
a IQB-5.6 means I Q B w i t h a 5.6% weight r e d u c t i o n p r i o r t o b l anch ing . IQB-0 means IQB wi thou t p red ry ing . Deep bed means deep bed steam b lanch ing .
Each sample w a s compared t o a c o n t r o l sample. The c o n t r o l w a s canned t h e same day as t h e expe r imen ta l sample. The t o p number i s t h e l e v e l of s i g n i f i c a n c e and t h e bot tom t h r e e numbers r e p r e s e n t number o f judges p r e f e r r i n g expe r imen ta l sample, c o n t r o l and no p r e f e r e n c e , r e s p e c t i v e l y . NS means no s i g n i f i c a n t d i f f e r e n c e .
b
I n c o n c l u s i o n , I Q B wi thou t p red ry ing i s a n e f f e c t i v e way of b lanch-
i n g b e e t s w i t h reduced e f f l u e n t g e n e r a t i o n . Beet t i s s u e i s ex t r eme ly
s e n s i t i v e t o h i g h t empera tu res r e s u l t i n g i n loss of t i s s u e j u i c e .
P red ry ing r educes e f f l u e n t f u r t h e r ; however, p roduct q u a l i t y i s ad-
v e r s e l y a f f e c t e d . Blanching p r i o r t o canning would b e an e f f e c t i v e
way t o i n s u r e meet ing d r a i n e d we igh t s f o r b e e t s .
CARROTS
C a r r o t b l anch ing d a t a are summarized i n Table 24. C a r r o t s , l i k e
o t h e r r o o t c r o p s , b e e t s and p o t a t o e s , are n o t normal ly blanched
a f t e r s l i c i n g o r d i c i n g u n l e s s t hey are t o b e f r o z e n o r dehydra ted .
The re fo re , t h e r e w a s no commercial b l anch ing o p e r a t i o n t o moni tor
i n t h i s s tudy . Even though t h e whole c a r r o t receives a h o t water
and steam t r e a t m e n t p r i o r t o p e e l i n g , pe rox idase a c t i v i t y w a s s t i l l
p r e s e n t i n t h e s l i c e d c a r r o t s . The v a l u e s i n Tab le 24 f o r e f f l u e n t
49
Table 24. SUMMARY OF CARROT B U N C H I N G DATAa
T o t a l E f f l u e n t o r g a n i c T o t a l
Blanching g e n e r a t i o n BOD5 n i t r o g e n phosphorus
IQB-0 192 2.0 0.10 0.016
Deep bed 225 2.6 0.14 0.023
t r ea tmen tb ( l . / kkg) (k- ( k g /kk g ) ( k g /kk g )
-
S o l i d s Product 10s t as y i e l d p roduc t
91.8 1.93
88.4 2.77
(%) (%)
gene ra t ed are similar t o t h e o t h e r s r e p o r t e d i n t h i s s tudy . Pre-
d r y i n g would be expec ted t o r educe b l a n c h e r e f f l u e n t even f u r t h e r .
I n t h e o r i g i n a l s t u d i e s by Lazar e t al .3 c a r r o t s p r e d r i e d t o a
5.8% weight r e d u c t i o n produced o n l y h a l f as much e f f l u e n t as IQB
w i t h o u t predry ing . The product y i e l d v a l u e s r e p o r t e d h e r e i n d i -
c a t e d t h a t t h e c a r r o t s u r f a c e l o s e s some of i t s moi s tu re -ho ld ing
c a p a c i t y a s t h e s u r f a c e t empera tu re i s i n c r e a s e d s i n c e t h e l o s s e s
are i n excess of t h o s e c a l c u l a t e d from s o l i d s l o s s . The BOD/N/P
r a t i o averaged 122/6 .3 /1 ( range 117-126/6.1-6.7/1) i n d i c a t i n g t h a t
c a r r o t b l a n c h e r e f f l u e n t h a s adequa te n u t r i e n t s f o r
b i o l o g i c a l waste t r ea tmen t . The BOD/COD r a t i o w a s 0.87.
Table 25 p r e s e n t s t h e r e s u l t s on t h e o b j e c t i v e e v a l u a t i o n of
c a r r o t s . There w a s no s i g n i f i c a n t d i f f e r e n c e i n e i t h e r t h e can
vacuum o r d r a i n e d we igh t s when steam blanched samples were compared
t o c o n t r o l samples.
S u b j e c t i v e e v a l u a t i o n r e s u l t s f o r c a r r o t s are shown i n Tab le 26.
The p r e f e r e n c e of t h e t as te pane l f o r t h e c o n t r o l sample i s markedly
e v i d e n t i n t h e s e d a t a . Th i s serves t o i l l u s t r a t e t h e importance of
50
Table 25 . SUMMARY OF OBJECTIVE EVALUATION OF CARROTS a
Blanching t rea tmentb
I Q B
Deep bed
Cont ro l
Months of S torage 1 3 6 9
Aver. Range Aver. Range Aver. Range Aver. Range
9 . 1 7.6-11.4 7.9 7.6-8.9 9 .9 5.1-16.5 1 3 . 7 12.7-15.2
11 .7 8.9-15.2 1 0 . 9 7.6-12.7 8 . 1 2.5-15.2 1 4 . 0 12.7-15.2
9 . 1 7.6-11.4 7 . 1 3.8-8.9 7.9 2.5-12.7 1 0 . 9 10.2-12.7
I Q B 284.0 280.1-285.5
293.9 291.1-295.4 Deep bed
286.6 284.0-288.8 284.3 281.4-287.9 283 .1 278.1-286.6
292.5 290.7-293.4 290.5 285.9-293.2 293.7 291.5-295.2
267.5 259.4-274.7 265.5 262.5-277.7 280.6 272.4-292.2 278 .3 273.0-284.8
a Each average cons i s t ed of t h r e e obse rva t ions .
Cont ro l samples were n o t blanched p r i o r t o canning. The whole c a r r o t was t r e a t e d i n h o t water and steam be fo re pee l ing .
IQ B
Deep bed
Table 2 6 . SUMMARY OF SUBJECTIVE EVALUATION OF CARROTS
0-11-5 6-13-7 , 5-12-3 1-9-10
0.1% 0.1% 0.1% 0.1% 2-11-7 5-10-6 4-11-5 2-8-10
Sto rage timeb Blanching I (months ) treatment" I 1 3 6 9
0.1% I 0.1% I 0.1% I 0.1%
51
c o l o r i n product e v a l u a t i o n . The steam blanched c a r r o t s were t r a n s -
po r t ed t o t h e l a b o r a t o r y and t h e r e w a s c o n s i d e r a b l e da rken ing of t h e
t i s s u e even though i t w a s h e l d under water. The taste pane l p r e f e r r e d
t h e b r i g h t e r orange c o l o r of t h e c o n t r o l . I n t h e s t u d y by Lazar e t
a l .3 IQB samples were judged t o be b e t t e r t h a n t h e c o n v e n t i o n a l l y
steam blanched p roduc t . I n t h e o p i n i o n of most of t h e judges t h e o n l y
d i f f e r e n c e between samples i n t h e p r e s e n t s t u d y w a s c o l o r .
I n c o n c l u s i o n , IQB can be used t o b l anch c a r r o t s p r i o r t o cann ing ,
f r e e z i n g o r dehydra t ion . There w a s no a d v e r s e e f f e c t s of t h e steam
b lanch ing t r e a t m e n t on c a r r o t s p r i o r t o canning . Blanching of c a r r o t s
p r i o r t o canning could be recommended i f t h e r e are unduly long d e l a y s
between c u t t i n g and can f i l l i n g . During t h i s d e l a y c o l o r changes
could occur .
LOADING RATE AND SIZE OF COMMERCIAL IQB UNITS
One of t h e b a s i c p r i n c i p l e s i n h e r e n t in . IQB i s t h a t each piece of
v e g e t a b l e r e c e i v e s t h e same thermal energy as eve ry o t h e r p i e c e . I f
t h e r e i s some c o n d i t i o n which a l t e r s exposure t ime o r ra te of h e a t
t r a n s f e r t o t h e s u r f a c e of t h e v e g e t a b l e , t h e n t h e r e i s t h e p o s s i -
b i l i t y of underb lanching . I n h e a t t r a n s f e r t h e t o t a l q u a n t i t y of
h e a t t r a n s f e r r e d i s d i r e c t l y p r o p o r t i o n a l t o t h e exposed s u r f a c e
area. Loading c o n d i t i o n s which w i l l d e c r e a s e t o t a l s u r f a c e exposed
may r e s u l t i n unde rp rocess ing and t h e r e f o r e b e l t l o a d i n g ra te i s an
ex t remely impor tan t v a r i a b l e i n t h e IQB p rocess .
The b e l t l oad ing rates f o r t h e h e a t b e l t , ho ld b e l t and deep bed
steam h e a t i n g b e l t were c a l c u l a t e d based on through-put , r e s i d e n c e
time and b e l t dimensions. The r e s u l t s f o r each run are g iven i n
t h e Appendix.
52
To summarize t h e d a t a , t h e f o l l o w i n g o b s e r v a t i o n s can be made: 1 )
Heat b e l t l oad ing- - fo r t h e I Q B p rocess t h e h e a t b e l t w a s loaded a t
approximate ly 4.9 kg/m
be op t ima l l oad ing f o r expos ing each p i e c e t o t h e steam c o n d i t i o n s
i n t h e h e a t s e c t i o n . This load ing w a s recommended i n p rev ious p u b l i -
c a t i o n s on IQB ,
what h i g h e r , g e n e r a l l y 6.3 t o 9.8 kg/m (1.3 t o 2.0 l b . / f t ). With
t h e s e two p roduc t s h i g h e r p roduc t l oad ing rates could be used s i n c e
medium s l i c e s (3.2-4.4 cm. d i ame te r by 0.64 cm. t h i c k ) d i d n o t pack
and reduce h e a t t r a n s f e r s u r f a c e area a s much as o t h e r product forms
(i.e. peas, c o r n , lima beans , o r g reen beans ) . With d e e p bed b lanch-
i n g , l oad ing ra te w a s l i m i t e d by c o n f i g u r a t i o n of t h e equipment. The
deep bed w a s 5.1 t o 6.4 cm. (2 t o 2.5 i n c h e s ) d e e p r e s u l t i n g i n d i f - 2 f e r e n t l oad ing ra tes depending on p roduc t geometry: peas--12.9 kg/m
2 2 1 (1 l b . / f t ). For t h e s e p roduc t s t h i s would
For b e e t s and c a r r o t s , b e l t l oad ings were some- 3 2 2
2 2 2 2
2 2 (2.65 l b / f t ) ; corn--14.5 kg/m
(3.04 l b / f t ); green beans--7.03 kg/m2 (1.44 l b / f t ) ; p o t a t o e s - - 2 2 2 2 11.8 kg/m (2.41 l b / f t ); beets--16.4 kg/m (3.36 l b / f t ) and c a r r o t s - - 2 2 16.0 kg/m
(2.98 l b / f t ) ; lima beans--14.8 kg/m
(3.28 l b / f t ). Green beans had t h e lowest product d e n s i t y
i n t h e deep bed. This would be expec ted s i n c e c y l i n d e r s w i t h a
l e n g t h t o d i ame te r r a t i o of 3 : l have a v e r y low packing d e n s i t y .
Hold b e l t l o a d i n g s - - i n t h e IQB p rocess hold b e l t l oad ings v a r i e d
2 )
2 2 2 - 2 from 17.6 kg/m (3.6 l b / f t ) f o r p o t a t o e s t o 69.3 kg/m (14.2 l b / f t )
f o r green beans. Hold s e c t i o n b e l t l oad ing r e f l e c t s t h e compounding
e f f e c t of many v a r i a b l e s i n c l u d i n g r a t i o of h e a t r e s i d e n c e time t o
hold r e s i d e n c e t i m e , r a t i o of h e a t b e l t wid th t o ho ld b e l t w i d t h ,
and r a t i o of h e a t s e c t i o n l e n g t h t o ho ld s e c t i o n l e n g t h . For ou r
system t h e h e a t and hold b e l t s were n e a r l y t h e same wid th [21.6 cm
(8.5 i n c h ) wide h e a t b e l t ; 20.3 cm (8.0 inch ) wide hold b e l t ] and
t h e l e n g t h r a t i o was 3/1 [ i .e . 91.4 cm ( 3 f t ) h e a t s e c t i o n / 3 0 . 5 cm
(1 f t ) ho ld s e c t i o n ] . The r a t i o of h e a t b e l t l oad ing t o hold b e l t
l oad ing shou ld , under t h e s e c o n d i t i o n s , be e q u a l t o t h e r a t i o of t h e
l i n e a l v e l o c i t y of t h e hold b e l t t o t h e l i n e a l v e l o c i t y of t h e h e a t
b e l t .
53
l i n e a l v e l o c i t y ho ld b e l t l i n e a l v e l o c i t y h e a t b e l t
l oad ing ra te h e a t b e l t l oad ing ra te ho ld b e l t
The l i n e a l v e l o c i t y i s t h e l e n g t h of t h e b e l t d i v i d e d by t h e resi-
dence time i n t h e s e c t i o n and s i n c e L(Heat)/L(Hold) = 3/1, t h e load-
i n g r a t e on t h e h e a t b e l t / l o a d i n g ra te on t h e hold b e l t i s :
r e s i d e n c e t i m e i n h e a t s e c t i o n r e s i d e n c e time i n ho ld s e c t i o n
(Loading r a t e )
(Loading rate)Hold
o r
where L.R. = l oad ing r a t e , kg/m 2
and 7. = r e s i d e n c e t i m e , seconds .
Using h e a t h o l d times r e p o r t e d i n t h i s s t u d y , t h e s ize of a comer-
c i a 1 b e l t - t y p e IQB u n i t was c a l c u l a t e d and is g iven i n Table 27. A 2 2
h e a t b e l t l oad ing ra te of 4.9 kg/m (1 l b / f t ) and a hold b e l t
l oad ing ra te of 49 kg/m
t h e same as t h o s e r e p o r t e d i n Table 3. For comnerc ia l u n i t s i t
would be expec ted t h a t c o s t s f o r a n IQB b l a n c h e r of t h i s c o n f i g u r a -
t i o n would n o t be more t h a n t h a t f o r r o t a r y - t y p e water b l a n c h e r s of
comparable p roduc t ion c a p a c i t y . Compared t o c o n v e n t i o n a l steam b l a n c h e r s , IQB would be less c o s t l y s i n c e t h e IQB u n i t is c o n s i d e r -
a b l y s h o r t e r f o r t h e same produc t ion c a p a c i t y .
2 2 (10 l b / f t ) was assumed. Blanch times are
Regarding developments of hardware f o r I Q B u n i t s , t h e e n g i n e e r i n g
r e s e a r c h team a t Western Regional Research Labora to ry , USDA,
Berke ley , r e c e n t l y r e p o r t e d ” on t h e development of a p r o t o t y p e
I Q B u n i t u s i n g s p i r a l v i b r a t i n g conveyors. High p roduc t ion rates,
compactness, s i m p l i c i t y and c o n t r o l of r e s i d e n c e t ime were claimed
54
f o r t h e u n i t . A l a r g e r p ro to type is planned f o r cons t ruc t ion .
Prodbc t
Peas
Corn
Lima beans
Green beans
Po t a t oes
Car ro t s
Beets
Table 27. ESTIMATED I Q B PRODUCTION UNITSa
(kkg product /hr )
9.1
13.6
13.6
13.6
4.5
5.7
5.7
I
Product ion r a t e
( tons p r o d u c t / h r l
10
15
15
15
5
6.3
6.3
a Heat 1.52m (5 f t ) wide x 9.14 m (30 f t ) long loaded a t 4.9 kg/m2 (1 l b / f t 2 ) .
Hold 1, 2 m (5 f t ) wide x 1.37 m (4.5 f t ) long loaded a t 49 kg/m 1 (10 l b / f t 2 ) .
55
SECTION V I 1
UNITS FOR INTERCONVERSION OF DATA
To a i d i n the i n t e r c o n v e r s i o n and i n c r e a s e d d i g e s t i b i l i t y of d a t a con-
t a i n e d i n this r e p o r t , several impor t an t conve r s ion f a c t o r s are p re -
s en ted i n t h e f o l l o w i n g t a b l e :
Tab le 28. FACTORS FOR INTERCONVERSION OF DATA
I To c o n v e r t from:
cm
g
kkg
kg /m2
cm
1. /kkg
kg/kkg
1. / h r
1. /case
To : I M u l t i p l y by:
f t .
ounces
t o n
l b / f t2
i n .
g a l / t o n
l b l t o n
ga 1 / h r
ga l /case
0.0328
0.0353
1.103
0.205
0.394
0.240
2.00
0.264
0.264
A l l of the v a l u e s con ta ined i n t h i s r e p o r t based on t h e amount o f
product were c a l c u l a t e d based on t h e amount of p roduc t (kkg o r t on )
processed. It i s f r e q u e n t l y d e s i r a b l e to know e f f l u e n t g e n e r a t i o n
based on p l a n t i n p u t rather t h a n p l a n t o u t p u t . T h e r e f o r e , t o f a c i l i -
t a t e these c a l c u l a t i o n s the f o l l o w i n g are g iven :
56
Table 29. CANNING YIELD FACTORS
Ton r a w product a b Pounds product Cases Product case t o n r a w product t on processed p roduc t
Peas 15.5 115 1.13
Corn 15.75 32 3.97
Lima beans 13.5 130 1.14
Green beans 13.5 125 1.19
Po ta toes 16.5 75 1.62
Beets 16.5 70 1.73
C a r r o t s 14.6 65 2.10
a
b Calcu la ted based on f i l l weight .
Reference 12.
57
SECTION V I 1 1
REFERENCES
1. Weckel, K. G . , R. S. Rambo, H. Veloso, and 3. H. von Elbe . Vegetab le
Canning Process Wastes. R e s . R p t . No. 38. Col lege of A g r i c u l t u r a l
and L i f e S c i e n c e s , Univ. Wisconsin-Madison, p. 1-20, 1968.
2. Na t iona l Canners A s s o c i a t i o n . R e s . I n fo rma t ion B u l l . No. 170 ,
January 1971.
3 . Lazar , M. E . , D. €3. Lund and W. C. D i e t r i c h . IQB: A New Concept i n
Blanching. Food Tech. 25:684-686, J u l y 1971.
4 . Lund, D. B . , S. L. Bru in , Jr . , and M. E. Lazar . I n t e r n a l Temperature
D i s t r i b u t i o n During I n d i v i d u a l Quick Blanch. J. Food S c i . 37:183,
January 1972.
5. Lund, D. B. A F i e l d Study on t h e A p p l i c a t i o n of I n d i v i d u a l Quick
Blanch. I n : Proceedings Thi rd Na t iona l Symposium on Food P rocess ing
Wastes. Washington, D. C . , U. S. Government P r i n t i n g Of f i ce . EPA-
R2-72-018, 1972.
6. S tandard Methods f o r t h e Examination of Water and Waste Water. 1 3 t h
ed. New York, A m e r . Publ. Hea l th ASSOC., I nc . , 1790 Broadway, 1971.
7. Van Buren, J. P., J. C. Moyer, D. E. Wilson, W. C. Robinson, and
D. B . Hand. I n f l u e n c e of Blanching Cond i t ions on S loughing , S p l i t t i n g
and Firmness of Canned Snap Beans. Food Tech. 14:233, 1960.
8. Ra l l s , J. W . , H. J. Maagdenberg, N. L. Yacoub, and W . A . Mercer.
Reduced Waste Genera t ion by A l t e r n a t e Vegetab le Blanching Systems.
I n : Proceedings Thi rd Na t iona l Symposium on Food P rocess ing Wastes.
Washington, D. C . , U. S. Government P r i n t i n g O f f i c e . EPA-R2-72-018,
1972. p. 25-70.
58
REFERENCES (cont inued)
9. Lee, F. A . The Blanching Process. I n : Advances i n Food Research.
Vol. 8. New York, Academic P res s . , 1958. p. 63.
10. Soderqu s t , M. R. , G. I. Blanton and D. W. Taylor . C h a r a c t e r i z a t i o n
of F r u i t and Vegetable Process ing Waste Waters. In : Proceedings
Third Na t iona l Symposium on Food Process ing Wastes.
D. C. , U. S. Government P r i n t i n g O f f i c e . EPA-R2-72-018, 1972.
Washington,
p. 409-436.
11. Brown, G. E. Pe r sona l Communication and paper p re sen ted a t the
Annual Meeting I n s t i t u t e of Food Techno log i s t s , M i a m i Beach,
June 1973.
12. . 1971-1972 Yearbook. Canner Packer. 140:9, 1971. p. 102.
59
SECTION IX
LIST OF PUBLICATIONS
1, Lund, D. B. The I n d i v i d u a l Quick Blanching Process . Michigan S ta t e
Un ive r s i ty . H i g h l i g h t s i n Food S c i e n c e , March 1973.
2 . Lund, D. B. Impact of t h e I n d i v i d u a l Quick Blanch (IQB) Process on
Cannery Waste Genera t ion . P resen ted a t t h e Four th Na t iona l Sym-
posium on Food P rocess ing Wastes, Syracuse , New York, A p r i l 1973.
3 . Lenz, M. K. and D. B. Lund. L e t h a l i t y C a l c u l a t i o n s f o r Heat/Cool
P rocesses by t h e L-Fo Method. Submit ted t o J. Food S c i e n c e , 1973.
60
A 1
A2
A 3
A4
A5
A6
A7
A8
A9
A10
A l l
A 1 2
A 1 3
A14
S e c t i o n X
Appendix - Raw Data
I n d i v i d u a l Blanching Trials f o r Peas
C h a r a c t e r i s t i c s of E f f l u e n t s Generated During Pea Blanching
I n d i v i d u a l Blanching Trials f o r Corn
C h a r a c t e r i s t i c s of E f f l u e n t s Generated During Corn Blanching
I n d i v i d u a l Blanching Tr ia l s f o r L ima Beans
C h a r a c t e r i s t i c s of E f f l u e n t s Generated During L i m a Bean Blanching
I n d i v i d u a l Blanching Trials f o r Green Beans
C h a r a c t e r i s t i c s of E f f l u e n t s Generated During Green Bean Blanching
I n d i v i d u a l Blanching Trials f o r P o t a t o e s
C h a r a c t e r i s t i c s of E f f l u e n t s Generated During P o t a t o Blanching
I n d i v i d u a l Blanching Trials f o r Beets
C h a r a c t e r i s t i c s of E f f l u e n t s Generated During Beet Blanching
I n d i v i d u a l Blanching Trials f o r C a r r o t s
C h a r a c t e r i s t i c s of E f f l u e n t s Generated During C a r r o t Blanching
Page
62
63
65
66
68
69
7 1
72
73
74
75
76
77
78
61
Table A l . INDIVIDUAL BLANCHING TRIALS FOR PEAS
R lanchinga t rea tment
IQB- 6 . 25-4-Als
IQB-0-4-Als
30 Sec-4-Als
Deep bed-4- A l s
IQB- 7.0- 3-Ala
IQB- 0- 3-Ala
30 Sec-3-Ala
Deep bed- 3- A l a
IQB- 7.5- Perf .
IQB-O- P e r f ,
30 Sec-Perf.
Deep bed- Perf . Averages
IQB-6.9
IQB- 0
30 Sec
Deep bed
- Treat- men t number
1 P
2P
3P
4P
5P
6 P
7P
8P
9 P
10P
11P
1 2 P
- Bel t Hea5
(kp;/m ; 5.08
5.42
5.42
13 . 13
4.49
4.39
4.20
13.52
5.42
5.86
5.22
12.20
-
5.00
5.22
4.93
12.93
- ,ad in8
Ho 11 (kg/m )
24.20
25.82 -- I-
21.52
20 . 94 -- --
25.91
28.01 -- --
23.86
24.94 -- --
- E f f l u e n t
gene ra t i o n ( l . / c a s e )
1.09
1.76
1.51
2.15
0.913
1.47
1.39
2.15
1.10
1.51
1.51
2.29
1.04
1.58
1.47
2.19
- 'roduc t y i e l d
(%)
88.8
87.5
90.0
83.8
90.0
90.5
91.3
83.8
87.5
90.0
90 .o 82.5
88.8
89.3
90.4
83.3
__ Solids l o s t as product
(%)
1.37
1.57
2.10
3.31
1.14
2.51
1.85
2.77
2.10
2.12
2.33
3.26
1.53
2.07
2.09
3.11
IQB-6.25 means IQB wi th a 6.25% weight r educ t ion p r i o r t o blanching. IQB-0 means IQB wi thout predrying. 30 s e c means h e a t on ly s t a g e of IQB. Deep bed means deep bed steam blanching. 4 o r 3 r e f e r s t o s i e v e s i z e ; p e r f e c t i o n w a s s i e v e s i z e 3 , 4 and 5. A l s means Alsweet; A l a means Alaskan; Perf . means P e r f e c t i o n .
a
62
Table A2. CHARACTERISTICS OF EFFLUENTS GENERATED DURING PEA BLANCHING
a Treatment number
1 P
2 P
3P
4P
5P
6P
7P
8 P
9P
10P
11P
12 P
Pipe
Pipe
Ave rag es
IQB-6 . 9
IQB- 0
30 Sec
Deep bed
Pipe
9 730
7260
11300
13200
10300
15800
10500
13400
15600
11400
13600
14200
8 300
7500
11900
11500
11800
13600
7900
T o t a l s o l i d s
(%)
1.99
1.43
2.16
2.58
1.94
2.66
2.04
2.16
3.06
2.18
2.40
2.44
1.54
1.42
2.33
2.09
2.20
2.39
1.48
T o t a l phosphorus
82
77
107
113
164
2 15
167
174
195
154
162
189
150
105
( P P 4
14 7
149
145
159
128
T o t a l o rgan ic n i t r o g e n
4 14
294
48 5
596
548
768
6 12
6 78
893
6 84
74 7
824
46 3
433
(PPm)
6 18
582
6 15
699
448
63
Treatment number
1 P
2P
3P
4P
5P
6P
7P
8P
9P
10P
11P
12P
Pipe
Pipe
Averages
IQB- 6 .9
IQB- 0
30 Sec
Deep bed
Pipe
Table A2 (cont inued) .
Jo la t i 1 e s o l i d s ( P P d 18000
13000
19600
23500
17300
23400
18200
19200
27100
19200
2 1200
2 1600
13400
12200
20800
18500
19 700
2 1400
12800
FLUENTS C juspendec vo l a t i 1c
s o l i d s ( P P d 644
476
595
58 1
329
547
473
389
2170
1120
1230
99 1
200
775
1050
7 13
765
654
488
JERATED C
Suspended s o l i d s
(%I .066
.055
.069
.070
034
.058
.052
.050
.224
.119
.132
. lo8
.025
.087
. lo8
.077
.084
.076
. 056
CHARACTERISTICS OF ZING PEA E
So lub l e phos pho rus
37
30
46
55
75
113
102
99
10 1
84
94
9 1
77
52
(ppm>
7 1
76
8 1
82
65
ANCHI N - - m3 - ( P P d
20
15
19
27
24
28
16
22
37
32
32
37
25
36
27
25
23
29
31 -
:rage
N03 NO2 : P P d _I
1.0
0.7
0.6
0.6
0.9
0.8
0.6
0.6
0.6
0.7
0.6
1 .o 0.6
0.9
0.8
0.7
0.6
0.7
0.8 -
See f o o t n o t e and t rea tment number on Table A l . b lanching.
P ipe means p ipe a
-
PH 7 .O
7 .O 7 .O 7.0
6.6
6.9
6.9
6.9
5.8
7 .O 5.9
5.9
7.7
7.3
6.8
7 .O 6.9
6.9
7.5 _I
No va lue i n d i c a t e s too s m a l l t o be measured.
64
Table A3. INDIVIDUAL BLAFCHING T R I A I S FOR CORN
Blanchinga t rea tment
IQB- 7.5
IQB- 0
20 Sec
Deep bed
IQB-7.5
IQB- 0
20 Sec
Deep bed
IQB-7.5
IQB- 0
20 Sec
Deep bed
Aver ag es
IQB- 7.5
IQB- 0
20 Sec
Deep bed
Trea tmen. number
1c 2c
3c
4 c
5c
6C
7c
8C
9c
1oc 11c
12c
- - B e l t Heat kg /m2
4.73
4.39
4.39
2.40
5.66
3.81
4.39
6.40
6.30
5.12
5.12
4.84
_I
5.56
4.44
4.64
4.54 -
)ad ing Ho 19
Lkg/m 1 22.59
20.94 -- --
27.08
18.30 -- --
30.11
24.40 -- --
26.60
21.23 -- --
E f f l u e n t :enera t ion
( l . / c a s e )
.489
.978
.822
1.17
.644
.921
1 .oo 1.20
.728
.819
.826
1.11
6.22
.906
.883
1.16
Product y i e l d
(%)
94.7
96.3
98.1
94.1
92.8
96.9
95.9
93.8
91.9
98.1
98.1
94.9
93.1
97.1
97.4
94.2
s o l i d s l o s t i s product
.50
1.43
1.00
1.90
1.14
1.75
1.87
3.19
.79
1.66
1.68
2.17
(%)
.81
1.61
1.52
2.42
a IQB-7.5 means I Q B with 7.5% weight r educ t ion p r i o r to blanching. IQB-0 means IQB wi thout predry ing . 20 s e c means h e a t on ly s t a g e o f IQB. Deep bed means deep bed steam blanching.
65
Table A4. CHARACTERISTICS OF EFFLUENTS GENERATED DURING CORN BLANCHING
a Treatment number
1c 2c
3c
4c
5c
6C
7c
8 C 9c
1oc 11c
12c
Pipe
Pipe
Pipe
Averages
IQB- 7.5
IQB- 0
20 See
Deep bed
Pipe
BOD5
10400
14000
12500
16600
24900
22700
28300
37800
13800
26500
3 1000
26800
3000
6500
11000
( P P d
16400
2 1000
23900
2 7000
6800
COD ( P P d
-- -- -- --
29900
32400
33400
51900
23300
34200
34500
30 700 -- -- --
26600
3 3 300
34000
4 1300 --
T o t a l s o l i d s
(% 1 1.94
2 .71
2.23
3.10
3.38
3.50
3.48
5.09
2.13
3.68
3.72
3.69
.455
.884
1.61
2.48
3.30
3.14
3.96
,983
To ta l phosphorus
104
159
135
170
105
132
14 2
189
87
172
16 9
154
30
40
72
(ppm)
99
154
149
1 7 1
47
T o t a l o rgan ic n i t rogen
(PPm) 177
296
231
260
211
255
2 56
322
196
368
398
3 18
68
100
208
195
306
295
300
125
66
E
V o l a t i l e Treatment s o l i d s
numb e r ( Ppm) 1c 2c
3c
4c
5c
6C
7c
8C
9c
1oc 11c 12c
Pipe
Pipe
Pipe
Averages
IQB- 7.5
IQB- 0
20 Sec
Deep bed
Pipe
18300
25600
20900
29 100
32400
33500
33300
48900
20500
35300
35900
34200
3970
8250
15200
23700
3 1500
30000
3 7400
9 140
Table A4 (cont inued) . FLUENTS C juspendec vo l a t i l c
s o l i d s ( P P d 1240
1700
3010
7 12
1780
6390
8660
246 0
1360
13400
4710
2060
2 15
46 0
1120
1460
7170
5460
1750
600
NERATED L
Suspended s o l i d s
f%)
.136
.179
.307
,076
.187
.639
.880
.247
.136
( 1.344)
.471
.206
.022
.047
.112
.153
.409'
.553
.176
.060
CHARACTERISTICS OF RING CORN
Soluble pho s pho rus
( P P d 50
89
86
98
101
106
114
151
17
38
37
24
15
30
18
56
78
79
91
2 1
LANCHING - 1 -
m3 ")
7
5
4
8
22
13
13
25
11
14
13
16
2
7
7
13
11
10
17
5 -
:rage -q N02 0
-
- c
NO2 0 --
-- -- --
.02
.03
.03
rrace
Inter
:nter
Inter
h t e r --
. l o :n t e r
.02
.03
.03
' race
.10 -
pH 6.5
6.4
6.8
6.8
7.0
7 .O
6.9
6.9
7.0
6.9
7.0
7.2 7.5
7.9
6.9
6.8
6.8
6.9
7.0
7.4 -
a See f o o t n o t e and t rea tment number on Table A3.
I n t e r f e r e n c e on a l l NO3-N de te rmina t ions .
The 1.344 v a l u e w a s n o t used i n t h e average s i n c e i t was h igher than corresponding va lues by f a c t o r of 10.
No va lue means too s m a l l t o be measured. I n t e r means i n t e r f e r e n c e .
C
67
Table AS. INDIVIDUAL BLANCHING TRIALS FOR LIMA BEANS
a B 1 an ch i ng t rea tment
IQB-5 .O
IQB- 0
20 Sec
Deep bed
IQB- 0
20 Sec
Deep bed
Averages
IQB- 5
IQB- 0
20 Sec
Deep bed
reatment number
1LJ3
2LB
3LB
4LB
5LB
6 LB
7 LB
Be l t '
Heat kg /m2)
4.83
5.76
6.10
15.32
4.39
5.12
14.35
4.83
5.08
5.61
14.84
)ad ing Ho I d
Ikg /m2 )
61.78
73.15 -- --
55.79 -- --
61.78
64.46 -- --
E f f l u e n t gene ra t ion
( 1 . / case)
.406
.879 . 750
1.00
1.22
.860
1.91
.406
1.05
.807
1.46
Product y i e l d
(%I 97.5
95.6
97.5
94.1
91.3
95.9
83.4
97.5
93.4
96.7
88.7
lo l id s l o s t is product
(%)
.24
.63
.34
.84
1.10
. 75
1.93
.24
.86
.54
1.38
a IQB-5.0 means IQB wi th a 5.0% weight r educ t ion p r i o r t o blanching. IQB-0 means IQB wi thout predrying. 20 s e c means h e a t only s t a g e of IQB. Deep bed means deep bed s t e a m blanching.
68
a Treatment number
1 LB
2 LB
3 LB
4 LB
5 LB
6LB
7 LB
P ipe
P ipe
P i p e
P ipe
Averages
IQB-5 .O
IQB- 0
20 Sec
Deep bed
Pipe
Table A6. CHARACTERISTICS OF EFFLUENTS GENERATED DURING LIMA BEAN BLANCHING
BOD ( P P d 5220
6170
5810
12800
13700
29900
16 300
1200
7 70
400
400
5220
9930
17800
14500
693
COD (PPm) 7790
11900
6750
13800
17600
12800
21200 -- -- -- --
7790
14800
9780
17500 --
T o t a l s o l i d s
(%)
1.20
1.48
0.91
1.77
1.96
1.80
2.42
.20
.13
.10
.10
1.20
1.72
1.36
2.10
.13
To ta l phosphorus
(PPm) 53
7 1
47
100
160
146
225
38
8
6
6
53
116
97
163
15
To ta l organic. n i t r o g e n
( P P d 34 1
557
3 18
495
864
560
8 79
42
26
27
28
34 1
711
439
687
31
69
Table A6 ( con t inued) . CHARACTERISTICS OF EFFLU
Vo l a t i l e Treatment solids
number ( P P 4
1LB
2LB
3L4B
4 LB
5 LB
6 LB
7 LB
P ipe
P i p e
P i p e
P ipe
Averages
IQB- 5 0
IQB-O
20 Sec
Deep bed
Pipe
9830
12300
74 70
14500
14100
15200
19600
1390
850
625
660
9830
13200
11400
17000
881
!ITS GENER jus pend ed vo la t i le
s o l i d s ( P P d
606
2320
1370
2250
2520
1660
2650
125
65
25
30
606
2420
1520
2450
61
PED DURIK
Suspended s o l i d s (70) .060
.240
.154
.228
.263
.182
.282
.014
.010
.004
.005
.060
.252 . 168
,255
.008
a See f o o t n o t e and treatment number on P i p e r e f e r s t o p i p e b l anch ing ,
I n t e r means i n t e r f e r e n c e .
LIMA BEAN
So lub le phosphorus
35
40
27
43
9
8
10
13
2
1
1
( P P 4
35
25
18
26
4
Ilable A5.
3LANCHING - NH3
( P P d
6
9
7
16
20
17
1 3
2
1
2
1
6
15
12
14
2 -
9 N03 N02
( P P 4
4.5
4.1
3.2
3.1
I n t e r
I n t e r
I n t e r
2.7
2.5
I n t e r
I n t e r
-
4.5
4.1
3.2
3.1
2.6 -
- b
NO2 Ppm)
. 07
. 05
.OS
.02
:n t er
:n t er
: n t e r
. 02
.02
Inter
: n t e r
-
. 07 . 05
.05 . 02
. 02 -
-
PH
6.8
6.7
6.8
6.4 6.5
6.6
6.5
8.5
8.6
7.9
7.6
-
6.8
6.6
6.7
6.5
8.2 -
70
Table A7. INDIVIDUAL BLANCHING TRIALS FOR GREEN BEANS
~~~ ~~
a Blanching t r e a t m e n t
IQB- 0
Deep bed
IQB-0,
IQB- C
h e a tment number
1GB
2GB
3GB
4GB
- Belt Heat, kg /m'
6.78
7.42
4.39
5.12
6.73
6.88
_I_
5.42
7.03
Averages
IQB- 0
Deep bed
oad i n g Ho Id
(kg /m2 > 86.72
-- 55.78
65.05
-- --
69.20 --
E f f l u e n t g e n e r a t i o n
(l./case>
1 mi30
1.10
.841
.883
.618
.603
1.01
. 773
a IQB-0 means IQB w i t h o u t p red ry ing . Deep bed means deep bed steam blanching .
'r odu c t y i e l d
(% > 90.0
92.8
96.3
95.6
99.4
99.7
94.0
97.3
S o l i d s l o s t as product
(%> --
2.09
1.88
.45
.34
.23
1.16
.89
71
Table A8. CHARACTERISTICS OF EFFLUENTS GENERATED DURING GREEN BEAN BLANCHING
~~ ~
a Treatment number
1GB
2GB
3GB
4GB
5GB
6GB
Ai erages
IQB- 0
Deep bed
a Trea t men t numb e r
1 G B
2GB
3GB
4GB
5GB
6GB
Averages
IQB- 0
Deep bed
BOD ( P P d
5890
9320
10100
2230
2560
1790
6070
4560
o l a t i l e s o l i d s
(PPm) --
10700
12000
2 700
2850
1980
7350
5190
COD (PPm) 29 10
6530 -- -- -- --
2910
6530
jus pend ed vo l a t i 1 e
so l i d s (PPm)
-- 19 1
1010
26 1
99
119
6 36
136
T o t a l s o l i d s
(a) --
1.26
1.43
.324
.341
.235
.877
.612
~ ~~
;us pended s o l i d s
(%) --
.026
.123
.036
.013
.016
.080
.018
To ta l phosphorus
53
72
8 2
2 1
24
17
(PPm)
52
38
So lub l e phosphorus
(PW) 36
42
4 11
1
1
17
15
N
ITH3 (PPm) 11
5
27
2
2
2
14
3
troge
No 3 N02 (PPm)
T o t a l o rgan ic n i t r o g e n
149
235
2 70
156
64
53
(PPm)
192
117
b
N02 (PPm) PH
7.9
6.5
5.3
5.2
5.1
5.5
-
6.1
5.7
a See foo tno te and t rea tment number on Table A7. NO /NO and NO were n o t determined. 3 2 2
72
Table A9. I N D I V I D U A L BLANCHING TRIALS FOR POTATOES
umber
lPOT
2POT
3POT
4POT
5POT
Blanchinga Treatment F= Heat,, (kg/m’j
3.56
5.76
11.76
5.76
5.08
3.56
5.51
11.76
t r ea tmen t
IQB-6.9
IQB- 0
Deep bed
IQB - 0
IQB- 0
Averages
IQB- 6 .9
IQB- 0
Deep bed
oad i n g Ho I d
(kg /m2
17.03
18.30 --
18.30
16.10
17.03
17.57
--
E f f l u e n t g en e r a t i o n (1. / case )
.754
1.31
1.25
1.40
.868
.754
1.20
1.25
Product y i e l d
(%>
93.1
93.1
93.8
92.2
95 .O
93.1
93.4
93.8
S o l i d s l o s t a s product
.43
.60
.78
.60
.61
(%)
.43
.60
.78
a IQB-6.9 means IQB w i t h a 6.9% weight r e d u c t i o n p r i o r t o b l anch ing , IQB-0 means IQB w i t h no predry ing . Deep bed means deep bed s team blanching .
73
Table A10. CHARACTERISTICS OF EFFLUENTS GENERATED DURING POTATO BLANCHING
cogen
%2 ( P P 4
12
11
16
10
1 3
1 2
11
16
a Trea t men t
number
lKIT
2 POT
3POT
4POT
5WT
Averages
IQB-6.9
IQB- 0
Deep bed
NO2
.29
.05
.09
.09
.05
( P P d
.29
.06
.09
Treatment number
lPOT
2WT
3POT
4POT
5WT
Ave rages
IQB-6.9
IQB- 0
Deep bed
BOD ( P P d 5000
4030
3780
4260
4720
5000
4340
3780
J o l a t i l e so l i d s ( P P d
7440
6010
8000
5 720
5550
7440
5760
8000
COD
(ppm> 6 340
4500
3640
4370
5790
6 340
4890
3640
T o t a l s o l i d s
C%) 0.930
0.746
1.01
0.707
0.856
0.930
0.770
1.01
7 75
1080
1490
1 7 1
1270
775
842
1490
.081
.114
,156
.020
.133
,081
.089
.156
T o t a l phosphorus
85
66
102
65
78
(PPm)
85
70
102
So lub l e phos phoixs
(PFd
48 46
57
4 1
52
48
47
57
T o t a l o rgan ic n i t r o g e n
(PPm)
302
264
39 7
249
329
302
281
39 7
Ni
NH3 (PPm)
24
20
36
23
25
-
24
23
36
-
PH
6.9
7.1 6.9
7 .O 6.9
-
6.9
7.0
6.9 -
a See foo tno te a n d ' t r e a t m e n t number on Table A9.
74
Blanchinga t r e a t m e n t
IQB- 5.6
IQB-0
Deep bed
IQB- 0
IQB- 0
Averages
IQB-5.6
IQB- 0
Deep bed
Table A l l , I N D I V I D U A L BLANCHING TRIALS FOR BEETS
Treatment number I
1 B
2B
3B
4B
5B
e l t : Hea3 :g /m
6.49
7.66
6.40
6.88
6.44
6.49
7.00
6.40
lading E f f l u e n t 1 Product '-1 g e n e r a t i o n y i e l d
27.62
32.55 --
29.28
27.47
27.62
29.77 --
1.48
1.84
1.68
1.61
1.74
1.48
1.73
1.68
I 86.3
87.8
~ 89.4
90.0
88.8
86.3
88.9
89.4
S o l i d s l o s t as product
5.21
4.01
5.26
3.76
4.29
(%>
5.21
4.02
5.26
a IQB-5.6 means I Q B w i t h a 5.6% weight r e d u c t i o n p r i o r t o b l anch ing . IQB-0 means IQB w i t h no p red ry ing . Deep bed means deep bed s t e a m b l anch ing .
75
Table A12. CHARACTERISTICS OF EFFLUENTS GENERATED DURING BEET BLANCHING
a Treatment number
1 B
2 B
3B
4B
5B
Averages
IQB-5.6
IQB- 0
Deep bed
Treatment number
1 B
2 B
3B
4B
5B
Averages
IQB- 5.6
IQB- 0
Deep bed
BOD ( P P d
29400
16700
21500
28600
19200
29400
2 1500
2 1500
V o l a t i l e s o l i d s (PPI 33600
20800
29000
21500
23100
33600
21800
29000
COD ( P P 4
29700
22600
25700
19200
25000
29700
22300
2 5 700
;uspended v o l a t i l e
so l i d s ( P P I
3 78
156
2 14
224
170
3 78
183
2 14
T o t a l s o l i d s
(%)
3.89
2.36
3.34
2.46
2.64
3.89
2.49
3.34
Suspended s o l i d s
( X I .056
,017
.022
.027
.021
.056
.022
.022
T o t a l phosphorus
( PPm)
145
9 1
136
98
95
145
95
136
~~~ ~
Soluble phosphorus E
(PPmI
- Nil
m 3 PPmI
105
60
108
61
64
105
62
108 -
Tota l o rgan ic n i t r o g e n
( P P d
556
349
492
378
379
5 56
369
492
PH
6.6
6.6
6.5
6.7
6.6
-
6.6
6.6
6.5 -
a b See foo tno te and t rea tment number on Table A l l .
I n t e r f e r e n c e i n tes ts f o r s o l u b l e phosphorus, N02-N and NO - N . 3 76
Table A13. INDIVIDUAL BLANCHING TRIALS FOR CARROTS
a Blanching T r ea tmenl t r ea tmen t number
IQB- 0 1 CAR
Deep bed 2CAR
IQB-0, 3CAR
IQB- 0 4CAR
Averages
IQB- 0
Deep bed
- - B e l t
.g /m
9.86
6.01
9.86
8.64
- Hea5. -
9.45
6.01 -
.oading Ho Id
(kg /m2 )
41.82 --
41.82
36.60
40.06 --
E f f l u e n t g e n e r a t i o n
(1. /case)
1.30
1.49
1.27
1.27
1.28
1.49
a IQB-0 means IQB wi thout predrying. Deep bed means deep bed steam blanching.
Product y i e l d
91.6
88.4
91.9
91.9
(% 1
91.8
88.4
S o l i d s l o s t as product
(%)
1.54
2.77
1.86
2.39
1.93
2.77
77
Table A14. CHARACTERISTICS OF EFFLUENTS GENERATED DURING CARROT BLANCHING
I BOD
a Treatment
numb e r ( P P J
1 CAR 8340
2 CAR 11700
3 CAR 10200
4 CAR 12500
Averages
IQB-0 10300
Deep bed 11 700
I I I I T o t a l T o t a l T o t a l o rgan ic
COD s o l i d s phosphorus n i t r o g e n ( P P d (%> (PPm) (PPm)
10600 1.02 66 439
12 100 1.56 1.00 623
10700 1.25 81 512
16400 1.61 106 649
12600 1.29 84 533
12100 1.56 100 623
phosphorus ( P P d
Trea t men t number
1 CAR
2 CAR
3CAR
&CAR
Averages
I Q R - 0
Deep bed
NH3 NO; NO2 (ppm) (PPm) (PPm)
Suspended V o l a t i l e vol-at i l e i s o l i d s s o l i d s
10600 j 283
59
100
80
97
79
100
39 30 25
56 44 36
40 38 33
48 49 29
42 39 29
56 44 36
12500
a See foo tno te and t rea tment
835
Suspended s o l i d s
(%>
.034
.044
.029
.097
.053
.044
10600
12 700
Soluble
429
436
number on Table A14.
pH 5.1
5.8
5.9
5.5
5.5
5.8
78 *U.S. GOVERNMENT PRINTING OFFICE: 1974 546-3181377 1-3