I 9 5 0 ] WERNER : PEELING ECONOMY 97

P E E L I N G E C O N O M Y AS A F F E C T E D OR I N F L U E N C E D BY SIZE A N D G R A D E O F T R I U M P H P O T A T O E S

H. O. WERNER 1,~

Unwersity of Nebraska Agricultural Experiment Station, Lincoln, Nebr.

(Accepted for publication, December 3 ° , 1949)

The Nebraska Agricultural Experiment Station, as part of its activity in the North Central Regional Potato Marketing Research Project, determined the peeling time and loss and the "ready to cook" cost of various sizes of U. S. No. I Triumph potatoes used in the marketing tests and also for potatoes of each of three lower grades.

E X P E R I M E N T A L P R O C E D U R E

Eighty tubers of each of nine sizes or grade classifications were selected from the stocks being sorted for the first car used in the North Central Regional Potato Research Project in January 1948. The designation, size range and average weight of the tubers of each size class or grade was as follows :

A. U.S. No. i, Sound Large 3 to 4 inches 311 grams* B. U.S. No. i, Sound Medium 2~ to 3 inches 16o grams C. U.S. No. I, Sound Small I ~ ,to 2tA inches 79 grams D. U.S. No. I, Slightly blemished Large 3 to 4 inches 274 grams E. U.S. No. I, Slightly blemished Medium 2~ to 3 inches 14o grams F. U.S. No. I, Slightly blemished Small 1% to 2~ inches 77 grams G. U.S. No. 2 grade i % to 4 inches 152 grams H. Culls, Salable but below U.S. No. 2 grade 1% to 4 inches 189 grams I. Very Small, Sound I~ to 1% inches 43 grams (*454 grams per pound).

Potatoes from these classes were assembled into 8o peeling lots by random selection of one tuber from each class for each lot. The class letter designation was written on each tuber with an indelible pencil as it was placed into a paper-bag containing one lot. To avoid errors that might result from the order of peeling if left to the choice by the peelers, the order in whi~ch the tubers in each bag were to be peeled was speci- fied on a sheet placed in the bag with the lot, and on the corresponding

1 Published with the approval of the Director as paper number 475, of the Journal Series, Nebraska Agricultural Experiment Station.

2 The author is indebted to Dr. Ruth M. Leverton of the Food and Nutrition Division of this Experiment Station for the services of the laboratory staff and for the cooperation of home economics students for quantitative peeling of the potatoes upon which this study is based. He also wishes to acknowledge the valu- able cooperation of Dr. F. A. Krantz of the University of Minnesota for con- structive criticism in revision of the manuscript.

9 8 THE AMERICAN POTATO 30URNAL [VoI. 27

record sheet. The peeling order was randomized, that is sequences were not systematic yet the same number of tubers of each class were peeled first, second etc.

A group of twelve women, on the staff of the Food and Nutrition Division peeled 48 lots, each woman peeling 4 lots. The other 3 2 lots of tubers were peeled by students in a home economics food class. The washed potatoes were weighed before and after peeling. Peeling time for each tuber was determined by each peeler by means of a stop watch.

For practical evaluation the percentage of usable and trimmed, (eyes and defects cut out) potatoes was calculated for each class of tu- bers from the total weight of all the tubers of each class before and after peeling. The time required for peeling potatoes of each class was deter- mined as minutes per pound of usable potatoes. Two over-aJl or eco- nomic criteria were computed : (a) the estimated :ost in Chicago of the usable potatoes when only peeling waste was considered and (b) peeling cost when time was charged for at a conservative rate (60 cents an hour) .

The retail cost of U. S. No. I that prevailed during the first week of the market i.e., 59 cents per Io lbs., was used for the U. S. No. I sound tubers. With the U. S. No. I slightIy blemished tubers the probable sell- ing cost was estimated at 54 cents per Io lbs. With the lower grades it was assumed that the price differentials at shipping points would still pre- vail in the retail stores. Hence U. S. No. 2 potatoes were figured at 48 cents per Io lbs., culls at 37 cents and the very small potato at 0. 7 cents. Throughout the ensuing report the discussion will be on the basis of Io pounds of potatoes, as that was the quantity pre-packaged for sale in most of the stores and was the prevailing quantity packed in consumer size bags at shipping point warehouses.

T A ~ L--Fariance anaylzed for usable potctoes and peeling time with 48 lots peeled by x2 Home Economics Women and all 8o lots.

Degrees i Usable Peeling Source of [ Potatoes, Time,

Freedom Variances Variances x2 Home Economics women (36 tubers, 4 each class or grade)

Class (Potatoes) 8 63I**** 94532**** Peelers 11 82o**** 36608**** Peelers X Class 88 22 iio6 Error 264 35 'a'2ia

All peelers (8o lots) Class (Potatoes) 8 z38z**** I39644"*** Peelers 79 236*** 9z2o*** Error 632 7I I952

*** Significant above the L0 per cent level. *-~--* Significant above the o.I per cent level.

I95O ] WERNER : PEELING ECONOMY 99

TABLE z- -Mean poumt usable (peeled) potatoes per each IO pounds from the eighty tubers of each size or grade class.*

Grade Quality

U. S. No. I Grade Sound Slightly blemished*

Lower Grades U. S. No. 2 Culls

Very Small

Tuber Size Class

Small Medium Large

Pounds Pounds Pounds

7.81 8.29 8.52 7.55 8.05 8.26

7.I4

Values significant at the o.I per cent level. Least significant difference o.18 lbs.

8.14"* 7.62**

* Values from slightly blemished tubers adjusted for tubers of same average weight as respective sizes of 15. S. No. I sound tubers.

** Included all sizes above I 7/8" but differing from U. S. No. x because of amount and extent of grade defects.

EXPERIMENTAL RESULTS

USABLE PEELED POTATOES FROM EACH SIZE

The differences in average weights of usable potatoes peeled out of size or grade class are significant at the o.I per cent level, as shown in table 2.* A similar significant difference was found in the efficiency of the peelers. No significant variance for the interaction of peelers' classes was obtained. These results indicate that irrespective of the peelers' efficiency the proportionate increase or decrease in usable pota- toes remained the same for the different sizes and grades of potatoes as you wilt also note in table I.

The quantity of usable potatoes peeled out of a given weight of po- tatoes increased as the size of the tubers increased. The relative rate of increase was greater f rom very small, to small and medium than f rom medium to large size (Table 2 and Figure I ) . The curve for U. S. No. I sound tubers shows that the increase in weight of usable potatoes peeled out of IO pounds of potatoes was greater as the average weight per tuber increased f rom 50 to IOO grams with an increase of four times that amoun t - - f rom IOO to 3'00 grams. The average amount usable per IO pounds was 7.3 pounds with the 5o-gram, 8.1 pounds, with the IOO gram, and 8. 5 pounds with the 2oo-gram tubers.

The usable potato weight peeled out of the slightly blemished tubers was less than that peeled from the sound tubers. From the curves in

*'Percen'cages of usable tuber "peeled out" of each of the 80 tubers of each of the 9 classes (sizes or grades) were used for variance analysis of weight of usable tubers.

I00 T H E A M E R I C A N P O T A T O J O U R N A L [Vol. 2 7

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MEAN WEIGHT-- GRAMS PER TUBER BEFORE P E E L I N G

Fig. 2--Pounds usable potatoes peeled from xo pounds of various sizes and grades of Triumph potatoes.

195o ] W E R N E R : P E E L I N G E C O N O M Y 1 O I

figure I it is seen for example that 8 pounds of usable potatoes were netted from IO pounds of sound potatoes averaging I IO grams, but that to net the sarde weight of usable stock from slightly blemished potatoes it was necessary to use tubers averaging i5 ° grams. I t is also seen that as the size of the tubers increased the detrimental effect of the blemishes increased because sound tubers averaging only 13o grams netted the same weight of usable potatoes per IO lbs. peeled--i.e. 8.2 pounds---as did slightly blemished tubers averaging 230 grams each.

P E E L I N G T I M E

The differences between both sizes and peelers in time required to peel ten pounds of usable potatoes was significant above the o.I per cent level. The variance due to interaction of peelers with classes was no greater than the variance for error. Hence the difference between in- dividual peelers did not change significantly from one size class to the other as shown in table I.

The average time, reported as minutes for peeling IO pounds of usa- ble potatoes decreased as the size of the tubers increased (table 3). The greatest differences in time required were found between sizes in the lower size range (Fig. 2). As the average weight of the sound tubers in- creased from 5 ° to IOO grams the time used in peeling io pounds of usable potatoes decreased from 127 to 75 minutes. With a further increase in average weight from IOO grams to 2o0 grams per tuber, the peeling time for IO lbs usable potatoes dropped to 57 minutes and finally to 42 minutes with the 3o0 gram tubers.

T A ~ 3.--Average time used in peeling 80 potatoes o[ each size or grade class-- reported as minutes per IO pounds*

Grade Quality

U. S. No. 1 Sound Slightly blemished

Lower Grades U. S. No. 2 Culls Very Small

Tuber Size Class

Small Medium Large

Minutes Minutes Minutes 91.3 61.1 4o.9

11o.8 65.1 4o.4

I53.7 Values significant at the o.I per cent level. I.,east significant difference lO.6 minutes.

71.6 75.9

Values from slightly blemished cubers adjusted for tubers of same average weight of respective sizes of U. S. No. x sound tubers. When peeling time is figured at 60 cents per hour the values in this table may be considered as ceres of cost for peeling to pounds of potatoes.

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195 o] WERNER: PEELING ECONOMY xo 3

Slightly blemished tubers required more pealing time than sound tu- bers. The differences were slightly greater with small than with large tubers. For example figure 2 shows that the minutes required for peeling out Io pounds of usable tubers were as follows: For tubers averaging IOO grams, 75 minutes with sound, 88 minutes with blemished, for tubers averaging 2oo grams, 53 minutes with sound, 58 minutes with blemished, and for tubers averaging 3oo grams, 42 minutes with sound, and 45 minutes with blemished.

RELATION BETWEEN PEELING TIME AND POUNDS USABLE

Generally the rapid peelers wasted most potato and conversely slow- er peelers generally turned out a greater quantity of usable potatoes from a given weight that was peeled. However, the performance of peelers varied greatly, some rapid peelers wasting relatively little and some slow peelers wasting a great deal. The extent of the inter relationship of peeling time and waste with three sizes of 13'. S. I potatoes is shown by the positive correlation coefficients presented in table 4. The degree of correlation apparently was not associated with size of tubers. The coefficients of variability, with time of peeling and the smaller coefficients for usable potatoes indicate that, on the whole, peelers differed more in the speed than in the care with which they peeled,

TAIlLE 4.---Comparison of mean zveight peeled out of IO pounds and time required to ~eel xo pounds usable potatoes and correlation coefficients for three

Tuber Sizes

groups of U. S. No. I tubers.

No. of Tubers

Pounds Usable per io Pounds

Peeled

Peeling Time Minutes

per IO Pounds Usable potatoes

s/a,

A&DB&E Large /

Medium C&F Small

x6o

x6o x~

Mean Coefficient Mean Coefficient Variability Variability

Lbs. Per cent 8.38 6.6 8.o4 7.6 7.78 8.6

Min. Per cent 43.8 49.5 66.2 39.5

IOL4 15.I

Correlation Coefficient,

Pounds usable and

Peeling time

I r .28I .129 .319

(Mean values differ slightly from average of means shown in tables 3 and 4 because these are based on actual not adjusted values for blemished tubers of each size.)

COST OF USABLE POTATOES

lJnder the conditions of the experiment when the retail prices were the same for all sizes of sound U. S. I potatoes - - 59 cents per IO pounds the largest tubers were the cheapest. When no charge is made for peeling time ten pounds of usable potatoes peeled from the large size cost 69. 3 cents. Those from the medium size cost I. 7 cents more and from the small an additional 4.6 cents (Table 6, Fig. 3)-

1 0 4 T H E A M E R I C A N POTATO .] 'OURNAL [ V o l . 2 7

TAat.E 5.--Weight of usable potato (pounds) lrom IO pounds and peeling time (minutes) for xo pounds usable potatoes with each of 16o large U. S. No. I grade tubers.

Minutes per lO Pounds Usable Potatoes

Pounds Usable Potatoes Peeled from Each io Pounds

6.0 6.5 7.0 I 7.5 I • 8.5 9.0

Number Each Time Division

105-120 90-lO5 75-90 60-75 45-60 30-45 15-30

Number each usable amount

I I

I I I

2 4 4 4

i 3 9 18 4 7 28 16 I 13 1 5 IO

I I 6 27 57 47

I 2 4 3 5 3 17 lO 36 3 58

39

21 160

Means : Weight usable per lO pounds - - 8.38 pounds. Time to peel IO pounds usable - - 43.8 minutes

r (correlation coefficient) ~ .281

TA~I~ 6.--Calculated cost of Io pounds of usable (peeled) potatoes of each size class, rolth retail price as reported for each grade without and with peeling time charges. (Values ]tom slightly blemished tubers adjusted

for tubers of same average weight as respective sizes of U. S. No. 1 sound tubers.)

Grade Quality

Without charge for peeling time U. S. No. I

Sound (59 cents) Slightly blemished (54 cents)

Lower Grades U. S. No. 2 (48 cents) Culls (37 cents) Very small (27 cents)

Charge for Peeling Time U. S. No. I

Sound Slightly blemished

Lower G r a d e s U. S. No. 2 Culls Very small

Tuber Size Class

Large Medium Small

Cents Cents Cents 69.3 71.o 75.6 65.4 67.1 71.5

59-5 47.8

37-7 at 6o cents per hour) Added

Dollars Dollars Dollars 1.1o 1.31 1.67 I.O9 1.34 1.82

1.29 1.21

1.82

i95o ] W E R N E R : PEELING E C O N O M Y I O 5

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MEAN WEIGHT-- GRAMS PER TUBER BEFORE PEELING

Figure 3- Cost per Io pounds of usable potatoes (peeled) from various grades and sizes with and without allowing for cost of time in peeling. Prices used were those prevailing in January I948.

From the chart in figure 4 (lower group of lines for cost of potatoes without peeling time figured in ) it is possible to calculate the retail price at which the different sizes would need to be bought to net Io pounds of usable potatoes at the same cost. For example, with the medium size (B) selling at 60 cents per Io pounds and Io pounds usable costing 72 cents, the customer could afford to pay 6I. 5 cents for large (A) but would have to buy the small for 56.5 cents. When peeling time is not considered, these large sound potatoes were actually worth about 2. 5 per cent more than the medium and the small were worth about 5.8 per cent less.

Although the slightly blemished U. S. I potatoes were priced at 5 cents less per io pounds, the cost of IO pounds of usable potatoes was only 3.9 to 4.1 cents less, indicating that these slight blemishes did not warrant a 5 cent per IO pound price differential.

3 ~

1 0 6 T I I E A M E R I C A N p O T A T O J O U R N A L [Vol. 27

When 6o cents an hour was paid for peeling, xo pounds of usable potatoes costs Sr.Io when derived from large potatoes in contrast with $I.3I from medium and $I.67 from small (Table 6, Fig. 4). When sound medium potatoes retailed at 60 cents per lO pounds the total cost of ro pounds of usable potatoes was $L32 (Figure 4). In order to get io pounds of usable potatoes at the same cost it would have been necessary

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Figure 4- Chart for calculating comparative cost per IO pounds of potatoes (with and without considering cost of peeling time) of each size and grade. The retail values of the potatoes from the various grades that would provide usable potatoes at any given cost occur at the point of intersection of a line projected at right angles from any point on the scale at the left.

195o ] WERNER : PEELING ECONOMY 10 7

to buy the small potatoes (C) at the rate of 32 cents per IO pounds whereas IO pounds of the large potatoes would have been worth 8o cents retail.

The total cost of usable potatoes from U. S. No. I blemished tubers was slightly greater than that of U. S. No I sound potatoes of the same size class. With U. S. No I sound of the medium size costing 6o cents per pound retail netting IO pounds usable at a total of $1.32 the total cost from slightly blemished medium tubers (E) would have been $1.55. In order to get the IO pounds usable tubers from blemished stock at this total of $1.32, it would have been necessary to buy them for 45 cents per IO pounds retail.

LOWER GRADES

U. S. No. 2 Grade. The mean weight per tuber of the 80 U. S.No. 2 grade tubers was 152 g r a m s - - a trifle greater than the mean of the 16o tubers of both U. S. No I groups of medium potatoes. The culls were about 20 per cent larger than the IT. S. No 2. The very small tubers (Class I) averaged slightly more than half as heavy as the U. S. No. I small.

With U. S. No. 2 tubers the size was a greater factor than the grade defects in determining waste and peeling time. The quantity of usable potatoes peeled out of IO pounds U. S. No. 2 (8.1 pounds) was midway between the quantities peeled out of U. S. No. I small and medium but greater than with slightly blemished U. S. No. I of these sizes (Table 2, Figure I). The peeling time was comparable to that of U. S. No. 1 medium (Table 3, Fig. 2). Because of this good peeling status plus the II cents price advantage this was a more economical grade for customers who were not concerned with peeling cost than were those of the six U. S. No. I classes, the cost of IO pounds usable having been only 59.5 cents per IO pounds. With sound U. S. No I medium selling at 60 cents per IO pounds, these U. S. No. 2 grade tubers were worth about 56 cents (without peeling time charge) instead of the price of 48 cents warranted by shipping point differential (Fig. 4). However when peel- ing time was included in figuring, the cost of usable U. S. No. 2 potatoes was 16 to 19 cents per IO poundg more expensive than U. S. No. I large but slightly cheaper than medium and much cheaper than small. Then when medium U. S. No. I sound tubers cost 60 cents per IO pounds the U.S. No. 2 potatoes were worth 51 cents which was a trifle higher than the retail price if adjusted to the differential at shipping point. Thus--on either basis of figuring cost, with the prevailing ship- ping point price differentials the U. S, No. 2 potatoes were a "better buy" than all except the large U. S. No. I potatoes.

IO8 THE AMERICAN POTATO JOURNAL [Vol . 2 7

Cull potatoes that are free from serious cuts or decay find a ready market at a greatly reduced price. Cracks and bruises were the chief defects causing these potatoes to be culls. About one-seventh were scabby and a few had large green portions. These cull potatoes suffered a heavy peeling loss but because of their relatively large size these losses were not any greater than with U. S. No. I small. Slightly more time was required to peel out Io pounds usable than with 15. S. I medium but not nearly as much as with U. S. No. I small. With the price differential of 22 cents per IO pounds these potatoes cost 47.8 cents per IO pounds usable without peeling cost. Thus for customers who did not need to figure cost of labor for peeling they were much more economical than either U. S. No. I or U. S. No. 2. When charges were made for peeling the cost of IO pounds usable potatoes, $1.21 was less than when they were obtained from U. S. No. 2 or any other grade or size except the U. S. No. I large potatoes. Of course it must be realized that because of the nature of some of these defects culls may not hold up so well in stores and kitchens as sounder tubers and they create a greater garbage disposal problem.

Very small tubers--between I ~ and i7/~ inches in diameter have been discussed casually in considering size of U. S. No. I potatoes. All these data indicate that if time is considered valuable the cost of peeling this size becomes too excessive to permit paying anything for them.

The comparative peeling efficiency of the 12 home economics wo- men is shown in figure 5 where the means for pounds usable peeled out of IO pounds are plotted against means for peeling time with the 36 potatoes peeled by each woman. Peeler :~3 was very slow but netted most potatoes per original IO pounds whereas peeler 12 was very fast but wasteful. The mean values fall along a fairly definite curve the up- turn of which indicates acceleration in use of time as the maximum quantity of usable potato was peeled out. In comparison with the others, the peeling efficiency of peeler I I was not commensurate with her lack of speed. In contrast the work of peelers I, 2 and 5 was distinctly su- perior because of relatively high speed combined with little waste.

I95o]

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T H E A M E R I C A N P O T A T O ~ O U R N A L [Vol. 2 7 IIO

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I 9 5 0 ] W E R N E R : P E E L I N G ]ECONOMY I l l

The relative efficiency of any peeler can best be estimated by the total cost of the peeled potatoes as it gives due consideration to care in peeling as contrasted with speed of peeling. The variation between peel- ers, the relative consistency of each peeler and the relative significance of care in peeling as contrasted with speed of peeling are shown graph- ically in the chart in figure 6. In this chart the mean cost for labor for peeling is plotted against the mean cost of the usable potatoes (potatoes only, no charge for peeling time) for each of the sound U. S. No. I sizes and the U. S. No. 2. and culls peeled by each of the Iz laboratory workers. The total cost per IO pounds usable is readily obtained by calculating the sum of the values at the point of intersection of lines projected from the bottom and side of the chart. All values falling along a diagonal line projected at an angle of 45 ° to the left from the lower base line represent equal total costs.

On the basis of the data depicted in figure 6, the following conclusions may be deduced:

A. When a financial value was placed on ti~e, the time of peeling was several times more important as a factor in final cost of usable pota- toes than was care in peeling.

B. There was a greater range in peeling time with culls than with the other grades.

C. The women who peeled any grade most rapidly were generally among the most rapid peelers with all other sizes and grades and vice versa.

D. Some peelers (for example 6 and I2) were able to turn out usable potatoes from U. S. No. I small for several cents per pound less than others (I, 3 and 4) could turn them out from U. S. No. I medium. It is of interest to note that the fast peelers (6 and I2) were able to peel out IO pounds usable potatoes from culls for less than others could from U. S. No. I medium.

D~SCUSSION

On the basis of these data it is evident that when potatoes are peeled by hand, the larger the potatoes, the less expensive they will be when ready for cooking. When peeled by machine, the percentage of waste on small potatoes is likely to, be proportionately greater. One disadvantage in using large potatoes is the length of cooking time, which is proportional to the least diameter of the tuber at the approximate rate

I I 2 T H E A M E R I C A N POTATO J O U R N A L [Vol. 2 7

of I minute per millimeter, or 26 minutes per inch of least diameter. Much or all of this difference can be eliminated by cutting the potatoes into halves or quarters. That, however, may be undesirable if the pota- toes are very mealy and hence likely to fall to pieces during boiling.

The use of low grades of potatoes is economically advantageous at the customary retail price differentials, especially when time of peeling is not considered. The disposal of waste is another factor mitigating against small potatoes and slightly less so against No. 2 and cull grades. The amount of waste to be handled with small or low-grade potatoes is 5 ° to 90 per cent greater than with U'. S. No. I large sound potatoes.

The relative prices at which potatoes of each size or grade need to be bought to provide usable potatoes at uniform cost can be calculated quite readily in figure 4 by projecting a horizontal line at right angles to a line arising vertically from any retail price. In table 7 there is a list of such prices based on usable potatoes at $1.32 per IO pounds from U. S. No. I sound or medium size selling retail at 6o cents per IO pounds and with peeling time figured at 6o cents per hour.

On this basis it appears that if potatoes are to be peeled, customers could afford to pay a premium of 2o cents per IO pounds for U. S. No. large sound potatoes but they would have to buy the U. S. No. I sound small for 32 cents--/.e, at a discount of 28 cents per IO pounds. These small tubers were worth considerably less than the culls. When consider- ing the charges normally incurred after a car is billed out at the shipping point until they are offered for sale in the retail store as the $2.20 per cwt. it will be seen that when selling at $3.8o per cwt. F. O. B. shipping point the large sizes sold for less than they were worth but the small U .S. No. I sound potatoes figured as being worth $2.80 per cwt. at shipping point, were selling for much more than they were worth when they were included in a U. S. No. I assorted grade. The slightly blemish- ed U'. S. No. I small tubers peeled by hand were not worth enough in Chicago to pay the merchandising and transportation charges. In con- trast to the unfavorable status of the small potatoes the U. S. No. 2 potatoes warranted a shipping price of $2.8o per cwt. which was prevail- ing at that time. However, the culls selling at $1.5o per cwt. were bringing less than their food value warranted--which was estimated to be $2.3o per cwt. F. O. B. shipping point. Of course, in that connection the greater risk of shrinkage due to decay and discarded stock must be considered by the retailer. No effort was made to determine the extent to which these advantages in buying lower grade potatoes at a reduced price are passed on to customers by merchandisers.

I 9 5 0 ] WERNER." PEELING ECONOMY I 1 3

S U M MARY

I. Records of peeling waste and time were obtained individually for a total of 720 Triumph tubers consisting of 80 tubers of each of nine sizes or grades.

2. Peeling waste and time was much less for large than for small potatoes. The rates of both decreased more rapidly as the size increased from small to medium than from medium to large U. S. No. I potatoes.

3. Blemished to U. S. No. i potatoes that were so slight as generally not to be considered as "damage" in establishing grades increased both peeling waste and time. In grades below U. S. No. I quality waste and peeling time were less than in If. S. No. I small and were similar to U. S. No. I medium.

4. There was a positive correlation between peeling speed and peel- ing waste, but when both potatoes and time are calculated at current rates the most rapid peelers prepared the potatoes most cheaply.

5. Among the U. S. No. I potatoes the large size was the cheapest and the small the most expensive source of usable potatoes when com- puted at prevailing shipping point price differentials for these classes. With all sizes the usable potatoes from the slightly blemished (rated at a reduction of 5 cents per IO lbs. retail) continued to be cheaper than the sound tubers. At still lower retail prices those from the U. S. No. 2 tubers were cheaper, and from the culls were cheapest of all classes of tubers over 17/8 inches.

6. When the charge for peeling was I cent a minute, the usable potatoes from large 13. S. No. I grade were the cheapest, followed by the culls, which were a cheaper source than U. S. No. 2 These, in turn, were cheaper than medium and small U. S. No. I potatoes.

7. The waste requiring disposition was the greatest with the culls and small If. S. No. I sizes and least with the large U. S. No. i class.

8. There was a great deal of difference between peelers in speed and competence in peeling. The differences carried through on a relative basis with all classes of potatoes.

9. When peeling time was considered the fast but frequently some- what wasteful peelers turned out usable potatoes at a considerably lower cost than painstaking but slow peelers. Some fast peelers turned out usable potatoes at lower cost from U. S. No. I small tubers than some others did from large U. S. No. I.

I I4 THE AMERICAN POTATO JOURNAL [Vol. 27

SUMMARY OF PAPERS P R E S E N T E D AT T H E POTATO CONFERENCE HELD AT T H E W E S T E R N REGIONAL RESEARCH LABORATORY, OCTOBER I7 and I8, I949

ESTIMATE OF TRENDS IN POTATO UTILIZATION

(Continued from Vol. 27, No. 2, February, I95o )

At the present time there are annually more than 30o million pounds of potato solids going into sewers from potato chip plants, with another I2 to 15 million pounds of solids going into sewers from potato flour plants. This wasteage contains not only starch, but is rich in enzymes and proteins. If these by-products could be captured by some method, the cost of which would not exceed their value, a very great step forward would have been taken in proper utilization. The by- products of the meat industry represent a greater profit dement to the packers than do their basic commodities. It is reasonable to assume that with the genius now being turned to the study of this problem, that the day is not far hence when the water soluble proteins from potato pro- cessing plants will be salvaged, and that enzymes, extremely valuable medicinally, will be developed from this present waste.

Few people probably think of potatoes in the form of starch or flour going into the manufacture of textiles or paper and paper boxes. These industries, however, offer outlets of a greater potential than has yet been developed.

All in all, the non-food utilization of potatoes offers the greatest challenge and quite possibly, the greatest opportunity for increased potato utilization.

In summing up, it appears that the trend in human consumption of potatoes is presently downward, but that it can be turned in an upward direction; that the potatoes manufactured into other foods are increasing materially; that potatoes used for seed would keep in line; and that potatoes used industrially might have a most interesting future.

- - W . A. Scott, E. Grand Forks, Minn.