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UNITED STATES DEPARTMENT OF AGRICULTUREAgricultural Research Administration

Bureau of Agricultural and Industrial Chemistry

PRODUCTION OF LEAF MEALS ¥MM VEGETABLE

WASTES IN ROTARY ALFALFA DRIERS

Eastern Regional Research Labora -

Philadelphia 18, Pennsylvania.

December 1950

L ! B R '

cuF.r.E .T :r; r :i

MAi i 1351

u.s. depart:.?.;.. :

ACKNOWLEDGMENT

The authors wish to acknowledge the valuableassistance of C. 0. Willi ts and co-workers in

establishing sampling techniques and analyzingthe products. They are also indebted toE. G. Kelley for technical advice and ar-ranging for supply of raw material and toMiles Willard for assisting in the dryingstudies.

PRODUCTION OF LEAF MEALS FROM VEGETABLE WASTES IN ROTARY ALFALFA DRIER

CONTENTS

Page

INTRODUCTION. .•.....„ u ....... . 1

GENERAL DESCRIPTION OF PROCESS . 1

DETAILS OF THE PROCESS. ..„'..„. „ . . „ n » „ 2

Chopping ........ o .. . 2

Drying . » . o . 2

EQUIPMENT o it a o o a o o o o o e a o a a * a o o a o d

TECHN \ QU E . . . . . . . . . . . . = . . . . . . . . .'. 3

EFFECT OF TEMPERATURE . , , . . . . . . . . i . . . . . 3

Pea vines. „ „}* ° . . . » o . » . . . . . » 4

BrOCCOll a a a a a o a . o a • a a a a a a a 4

Lima bean vines. . . . „ = o . . . a . a . . 4

Spinach waste. » * : .„: . '«. • a..« » o a . « • «. a a 5

Beet topS oooaaoe.aoofleaaaiBea 5

SEPARATION a o a o a . . a . . a a a a a a a a a a a a 5

S TEM RY I N G,' o • a o. a ) o a a o a a o a a o ' »• o • o • a Q o o O

STORAGE i) . o .' e. a . s a o ,»' o p •

.a p rr a • .

o. • * o' a a a 6

COST ESTIMATES. . n . » = . „ . . » = . - . . . .

'. • . 6

Fixed U Flit n * a * o m a o o o o ". • • ' o • p o o • a

P0rt3.bl6 Unitn po.can.ocaooooacocncioaBc /

COMMERCIAL USE - aaoiJeccGOSr,BO«cjeaa»asn.oe /

SUMMARY

A process has been developed whereby leaf meals of goodquality can be prepared from- vegetable wastes such as peavines, lima bean vines, broccoli, spinach, and beet tops by

fractional drying in high temperature, direct heat rotarydriers of the alfalfa type,

. Since the process provedfeasible for wastes of widely different characteris. bios-,

presumably wastes other +han those tested could be simi. larlyprocessed to produce good-quality leaf meals.

The total cost of making a ton of leaf meal from pea vines,lima bean vines, broccoli, spinach, and beet tops is est-3

mated to be $51, 45, 108, 68 and 114', respectively; for an.

individual enter-prise. For an operation auxiliary to anexisting business-, the cost, of making a ton of leaf mealfrom these wastes is estimated to be $43, 38, 90, 58, and95, respectively.- - To arrive at the seT ! 4r\g p^ ,r n "> + i'e

necessary to add only the cosi:of selling and a margin of

pro fit.

The leaf meals are in most cases richer than alfalfa meal,which is sold on a guaranteed basis of 100,000 I.. U, perpound 133 -p. p.m.; of carotene and 17 percent p'ret eirWith alfalfa meal of this guaranteed composition selling intha Philadelphia market a+. from f>53 to $86 "per ton, the production of certain vegetable leaf meals by the methodsdescribed herein can be a profitable enterprise in such anarea

.

PRODUCTION OF LEAF MEALS FROM VEGETABLE WASTES IN ROTARY ALFALFA DRIER

By Nicholas C, Aceto\ Paul W. Edwards 2, Roderick K, Eskew 3

,

Clifford S, Redfield 4, Rita F. Hurley 5 and Albert Hoerseh, Jr. 1

INTRODUCTION

A process for preparing high-grade vegetable leaf meals from field wastes inmoderate-temperature, through-circulation belt driers has been published bythe Eastern Regional Research Laboratory6,7 ,, This process, which conbistsin fractional drying at 240 F, , did not find wide industrial adoptionprincipally because moderate-temperature belt driers are costly and are lesswidely used in farm operations than rotary types. Direct-heat, rotaryalfalfa-type driers are cheaper per unit of evaporating capacity, are simpleto operate, and are widely used for processing farm crops,. Therefore thesuitability of this type of drier for the preparation of high-carotene,high-protein leaf meals from vegetable wastes has been investigated,,

GENERAL DESCRIPTION OF PROCESS

The process (for all wastes) consists essentially of the following steps*

(1) Chop in a rotary forage cutter<>

(2) Dry "fractionally," that is, until the leaves become dry and brittlebut the stems remain moist and tough,

(3) Detach the dry leaves from the moist stems. This is done by the fansthrough which the material passes,

(4) Separate the leaf fraction from the stem fraction by means of a vibra=ting screen equipped with suitable sieves,

(5) Collect partially dried stems for further drying or disposal, dependingon their value,

A few minor adjustments have to be made, depending on the waste to be dried.

These adjustments, which involve size of cut in rotary forage cutter andnumber and mesh of sieves for the vibrating screen, are discussed underDETAILS OF THE PROCESS.

' Chemical Engineers, Chemical Engineering and Development Division

" In Charge, Potato Products Development Section, Chemi cal Engineering and DevelopmentD) VS Si ON

.

3 Head, Chemical Engineering and Development Division

1Cost Analyst,. Chemical Engineering and Development Division.'

3 Engineering aide. Chemical Engineering and Development Division.

1 Process:ng Vegetable Wastes for H i gh° Protei n., H 1 gh = V i tam I n Leaf Meals, by David A.

Colkek and Roderick K, Eskew, U S Dept. Agr,. Bur Agr, and Indus Chem. A!C=76

(Eastern Regional Research Laboratory). March 1945. (Processed)

Preparation and Use of Leaf Mea; s from Vegetable Wastes, by J, J ; Will am an and RoderickK. Eskew, U. S Dept. Agr. Tech Bull. 9 58 October 1948.

-• 2 -

Figure 1 is a schematic representation of a commercial installation for theforegoing steps,

DETAILS OF THE PROCESS

Chopping

In order that the wastes may be easily conveyed and properly dried, theyshould be chopped into small pieces c The chopping should be done with aminimum of bruising because bruised leaves tend to lose carotene on standingand during drying; for this reason cutter knives should be kept sharp,, Tominimize bruising, the fan is removed from the forage cutter, and thechopped waste is delivered directly from the knives to the conveyor of thedrier, No screen is used beneath the knives. The chopped plant should befed directly to the drier to keep loss of carotene at a minimum.

Suitable chopping can be done with a forage cutter having "lawn mower" typeknives,. For pea and lima bean vines, the knives should be set for a cut ofone-fourth inch. For broccoli, spinach, and beet tops, they should be setfor a cut of 1 inch. The actual average size of the cut waste, however, issomewhat larger than the setting on the cutter.

Drying

EQUIPMENT

The drier used in our investigations (Fig. 2) was a small, commercial-si ze,

multiple-pass, oil-fired rotary drier. The rotating body, which is 16. feet

long, is made up of three concentric cylinders, 2-1/2, 5, and 7 feet indiameter, respectively. The inner cylinder is the combustion chamber. Theoil burner is mounted at one end of this cylinder, and protrudes from themain body, as shown at the right side of Figure 2„ The drying air, drawn in

by an exhaust fan through openings adjacent to the burner, is heated bymixing with the products of combustion,

The material to be dried falls from the chopper on the elevator, from which

a screw feeder forces it into the left end of the drier. Here it meets the

heated air and products of combustion and is carried by them, in the annular

space between the inner cylinder and the 5-foot cylinder, to the right end

of the body, then back between the 5- foot cylinder and the outer one to the

left end. Here the gases and the dried material enter the exhaust fan,

which delivers them to the cyclone separator adjacent to the drier. The hot

gases escape through the top of the separator, and the dried material falls

through the bottom. Here a stream of cold air from another fan picks up the

dried material and sends it to a cooling cyclone separator. The velocity of

this air is insufficient to pick up stones or gravel; any such material that

has entered the drier falls out through a tee in the duct at this point.

From the bottom of the second cyclone, the dried material falls to the

screen.

Presumably other properly designed driers of the rotary type, single or

multiple-pass, could be employed.

3 -

TECHNIQUE

The method of fractional drying, which consists of drying until the leavesare just dried, but the stems remain moist and tough, was developed firstwith ,& b ">.tt drier 6, 7

• It has been found in this work to be applicablealso to direct-heat rotary driers for four of the five wastes used. Thissystem of drying has advantages over total- 'drying, that is, drying the stemsas well as the leaves, both from the point of view of economy and quality ofthe products Although the stem portion contains some of the valuable con-stituents, the leaves contain by far the bulk of the carotene and protein.Also, the stem portion dries much more slowly than the leaf portion,, There-fore, if the stems were dried completely, the more valuable leaves would besubject to over-drying. Crushing or splitting the stems to increase theirdrying rate would injure the leaves and would also result in an inferiorproduct. From an economic point of view, fractional drying increases thehourly leaf meal output of the drier and decreases the fuel consumed per tonof meal produced. It minimizes unnecessarv evaporation of water from thestems, which are screened out in preparing leaf meal. Even though the stemsare to be used, it is preferable to dry them after separation from theleaves.

EFFECT OF TEMPERATURE

When availability of the waste permitted, high temperature studies were madein the rotary drier at inlet temperatures of about 850°, 1000°, and 1200° F,

The exhaust temperature was automatically set by adjusting the feed rate so

that the leaf portion of the fractionally dried product had the desiredmoisture content, for example, 10 percent. The maximum inlet temperaturestudied was determined by the maximum temperature possible in the drier,that is, 1250° F,

To evaluate the effect of high temperature drying on the valuable con-stituents of the vegetable wastes studied, simultaneous tests were made in

the through-circulation belt drier at 240° F, Because of the difficulty ofobtaining representative samples of the fresh waste, an absolute evaluationbased on the fresh waste could not be obtained,. For this reason, the belt-drier process was used as the standard by which the rotary drier was ap-

praised.

Table I shows a comparison of the results with the high-temperature and the

moderate-temperature driers on the basis of over-all carotene retention and

carotene content in the leaf meal per ton of fresh waste. The carotenevalues rather than the protein values (N x 6, 25) were used -as a basis of

evaluation, because protein is not affected bv drying temperatures in the

range studied.

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Table II gives the composition of the leaf meal and the stem fraction,moisture contents, and yields at drying conditions considered optimum on the

basis of drier capacity and retention of the valuable constituents*.. Thecarotene values are probably conservative, since an unavoidable delay of 5

to 6 hours occurred from the time of harvesting until the wastes were proc-

essed. Delay results in a loss in carotene, especially in pea vines and

lima bean vines, which are bruised in the vining operations.

Pea Vines: Drying of pea vines was studied at two inlet temperatures,

namely, 840° and 1030° F.. The average exhaust: temperatures which gave a

fractionally dried product were 281° and 293° F., respectively. As shown in

Table I, retention of carotene in the rotary drier at both drying tempera-

tures was about equal to that in the belt drier. However, on the basis of

pounds of carotene in leaf meal per ton of fresh waste, the rotary drier

method was superior. This was true because it was possible to dry frac-

tionally in the rotary drier?but not in the belt drier, thus permitting

better separation in the former. Therefore, pea vines can be dried satis-

factorily at about 1050° F. inlet temperature or perhaps at, somewhat higher

temperatures. Sufficient material was not available to make drying tests at

1200° F.

Broccoli: Three drying conditions for broccoli were studied-inlet tempera-

tures of 915°, 1090° and 1220° F. , and exit temperatures of 322°, 336° and

334° F.,respectively. As compared with that in the belt drier process,

retention of carotene in the rotary drier decreased as the inlet temperature

increased (Table l) . Loss of carotene at inlet temperatures of 915°,

1090° and 1220° F. was 2,0, 9.3, and 22.3 percent, respectively. Since

loss at the highest temperature was excessive, such an inlet temperature is

not recommended. Despite the slightly greater destruction of carotene at

the intermediate temperature, this temperature is preferable to the low

temperature because it;

increases drier capacity 30 percent,. Although the

exhaust, temperatures at the intermediate and high inlet, temperatures were

about the same, loss of carotene was much greater at. the high temperature^

22.3 and 9.3 percent, respectively. Yields of carotene per ton of fresh

waste at the intermediate and low temperatures were about the same as those

obtained with the belt drier.

Lima Bean Vines: The whole viner waste was used in making these tests,

instead of the "apron" fraction as described in AIC-76 6 and Technical

Bulletin 958 7. The "apron" 1 fraction from the viners consists mainly of

leaves and a small amount of stems. This fraction, however, was not avail-

able in the large quantities necessary for our studies, and it may not be

available for large-scale production.

The inlet and outlet temperatures at which the vines were dried were 863°

and 280°, 1040° and 290°, 1245° and 294° F., respectively. Again the re-

tention of carotene decreased with • increase of inlet temperature, despite

the fact that the outlet temperatures at' the intermediate and high inlet

temperatures were practically the same. On the basis of carotene retention

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per se, the lowest temperature investigated was the best. The loss at theintermediate temperature was only slightly greater (9. 4' p ercent

) ,however,

and this temperature is recommended, since it increased the drier capacityby about one-third. The highest inlet temperature is not recommended be-cause of the excessive loss of carotene ( 36. p ercent ) . Again, as in dryingbroccoli, at the low and intermediate inlet temperatures yields of < caroteneper ton of waste were as good as those obtained with the belt drier.

Spinach Wastes The spinach waste studied consisted mainly of leaf, withlittle stem material. Since the small amount of stem material dried toabout the same extent as the leaf, a whole meal was prepared. Three inlettemperatures were investigated, namely, 900°, 1035° and 1225° F. The outlettemperatures were 324°, 340° and 331° F.

,respectively. Loss of carotene

was the same at all three temperatures-~about 15 percent (Table I). Inall cases, the yields of carotene per ton of waste were lower than in thebelt drier. The highest inlet temperature is recommended, since it in-creased production of meal almost 80 percent over that at the low tempera-ture and about 45 percent over that at the intermediate temperature.

Beet Tops: The optimum temperature for drying beet tops was not determined,because enough waste to complete the studies was not available. Only oneinlet temperature--1035° F. - was tested with reasonably fresh material.Table I shows that loss of carotene at this temperature was about 16. per-cent. Although this loss was moderately high, a good quality leaf meal wasproduced. Therefore, drying beet tops in a rotary drier may be consideredfeasible, at least as far as quality of product is concerned.

A test was made at 860° F. with beet tops stored overnight. Although thewaste showed no deterioration, as determined by the belt-drier test, theresults were contrary to those obtained with all other wastes studied, inthat the apparent loss of carotene was greater at the lower inlet tempera-ture—approximately 28 percent. Under these circumstances, no definiteconclusion can be drawn.

SEP ARATI ON

When the fractionally dried material passes through the drier and the fans,

the fan blades detach the friable leaves from the moist tough stems. Themixture is passed over a vibrating screen equipped with sieves havingopenings that allow the- fragmented leaf to pass through, thereby separatingit from the stems.- For lima bean and pea vines, a 5-mesh sieve having0. 16'- inch square openings is suitable; an 8-mesh sieve having 0.097-inchsquare openings is suitable for broccoli, beet tops, and spinach. It wasfound that the screened spinach stems, which represented 7 percent of thetotal, could be added to the leaf meal, since they were dry and were high in

protein and carotene. No screening is necessary for spinach waste.

In drying lima bean vines, a 60-mesh sieve should also be provided forremoval ,of the soil. This procedure is not altogether effective, as indi-

cated by the ash content of the leaf meal retained on a 60-mesh screen(Table II). Removal of soil is complicated by the fact that the leaf fines

pass through with the soil and hence are lost. Therefore, 60-mesh is recom-

mended as a compromise between complete soil removal and retention of leafconstituents.

- 6 -

A method of harvesting lima bean vines in which the plant is cut aboveground instead of being pulled up with the root attached is under investiga-tion at certain farms. If the cutting method can be used successfully, thesoil problem will be minimized.

For spinach and beet tops, however, removal of soil with a 60-mesh sieve wasfound inadvisable because so much leaf meal was removed with the soil.

STEM DRYING

A question is posed as to the utilization, if any, of the partly dried stemsobtained in the separation step. Their value as a source of carotene ispractically negligible. ' Stems from some of the wastes, however, are rich inprotein (Table III). Therefore, when justified by their protein content,the stems should be accumulated and dried at the end of the operating day.To expose more surface and thereby increase their drying rate, they shouldbe split or crushed before drying. Since preservation of carotene is not a

factor, inlet temperatures as high as 1250° F. or higher can probably beused. Screened broccoli stems, for example, represent about 33 percent ofthe total solids in the waste. Since the drier has an average evaporatingcapacity of 2350 pounds of water per hour at an inlet air temperature of1250° F. , it should be capable of drying the crushed, partly dried stemsaccumulated in 23 hours' operation in less than 1 hour. This would produce1550 pounds of stem meal in a portable drier of the type used in our work.

As shown in Table II, broccoli leaf meal should contain about 518 p. p.m. of

carotene and 39.5 percent protein. The dried <= + ems (assuming all thecarotene were lost at the high temperature employed in drying them) would

contain no carotene but about 25 percent protein. A whole broccoli mealconsisting of two-thirds leaf meal and one-third separately dried stems

would have approximately the following analysis: carotene, 346 p. p.m.-;

protein, 34' percent; fiber, 11.3 percent. Guaranteed alfalfa meal is

largely sold on the basis of 133- p. p.m. of carotene, 17 percent protein and

about 27 percent fiber.

STORAGE

No work was done on the storage of leaf meals produced in the rotary direct-

fired drier. It is expected, however, that storage conditions that have been

found suitable for alfalfa meals will also be suitable for vegetable leaf

meal s.

COST ESTIMATES

Fixed Unit

Estimates of the cost of making vegetable leaf meals, by the process recom-

mended here have been made on two bases-- (a) as an individual business

enterprise and (b) as an operation auxiliary to an existing business, for

example, vegetable processing. The cost for Case (b) is less because certain

expenses are shared with the existing business. For example, items such as

TABLE ill

YIELDS AND ANALYSES OF PARTIALLY DRIED STEMS FROM VEGETABLE WASTES

Yield-'

of original Mo is- CrudeStems waste tore Protein 1 Fiber y

"

01 of 01 aljo jo to jo

Spinach 7 10 27.6, 15.3

Broccoli 33 53 24.0 16,7

Beet tops 22 38 16, 2 12.

9

Kal'e 43 62 16,1 9.9

Pea vines 47 38 10.6, 25.3

Carrot tops 42 46, 10.0 18.0

Lima bean vines 46, 34 7.7 51.8

Moisture -free basis.

- 7 -

land and site preparation, roads and parking areas, erection of manufac-turing equipment, power, engineering fees, indirect labor, and indirectexpenses, would be lower than for Case (a). The costs given are for a plantlocated in the Middle Atlantic States. These estimates assume an instal-lation of two rotary alfalfa-type driers, each having a rated evaporativecapacity of 6000 pounds of water per hour for the drying of alfalfa* Theyinclude the costs of all the auxiliary equipment, a building for housing thescreening and bagging facilities, and warehouse space for one week's pro-duction. The driers are not housed* Table IV shows capital costs.

The costs assume that the plant will operate 24 hours a day for at least150 working days per year* A period significantly less than this might wellresult in an unprofitable enterprise*

The figu res for "Costs to Make" given in Table V for Case (a) and in TableVI for Case (b) , include not only the actual production costs but all otheritems, such as administration, general expenses, research, interest oninvestment, and working capital* Thus, to arrive at a selling price it isnecessary to add only the cost of selling and a margin of profit*

Table VII gives the engineering data on which the cost estimates are based*

Portable Unit

Consideration was given to the feasibility of operating an itinerant port-able unit employing a drier of the type used in our work. It was found that

under such conditions the cost to make leaf meal would be from 30 to 45 per=cent higher than the figures shown for Case (a) *

COMMERCIAL USES

Although no feeding tests have been made on vegetable leaf meals preparedin a direct-heat drier, there is no reason to expect that they will bedifferent from leaf meals of comparable composition prepared in a belt

drier. Data have been published on feeding tests with leaf meals prepared

at the Eastern Regional Research Laboratory in a low-temperature beltdrier* 7 - 8 - 9

-

10 n ' 12 ' 13

8A Preliminary Investigation on the Use of Certain Dried Vegetable Wastes as PoultryFeeds, by A, E Tomhave. Edmund Hoffmann, E. g Kelley. M E. Wall and D. A. Colker,Delaware Agr- Expt St Bull 247 Apr,l 1944.

9 Broccoli Leaf Meal for Alfalfa Meal in Broiler Rations by Edmund Hoffmann.. A. E, Tom =

have, Edward G. Kelley an o Monroe E, Wall. Feedstuffs 17 (8): 25- 27 1945.

10 Carotene from Vegetable Leaf Wastes Compared with Vitamin A in Chick Rations, by W C.

Skoglund. A. E. Tomhave, and A F K.sh. Delaware Agr. Expt Sta. Bull. 268 July 1947-

11Carotene from Vegetable Leaf Wastes Compared with Vitamin A ,n Laying Rations. By W. CSkoglund A, E. Tomhave and C W. Mumford. Poultry Sci. vol. xxvill, no, 2, p. 298=

300, March 19 49.

12 Composition and Apparent Digestibility of the Carbohydrate and Other Constituents of Pea

and Lima Bean Vines When Fed to Sheep, by Max Phillips, C, 0. Miller, and R. E. Davis.J. Agr. Research vol. 73 p 177.187 1946

13 apparent Digestibility by Sheep of L i gn i n in Pea and Lima Bean V.nes, by R E Dav.s.C, 0. Miller and I. L Lindahl. J. Agr. Research vol. 74. p. 285=288. 1947.

TABLE IV

CAPITAL COSTS OF PROCESSING VEGETABLE WASTES IN ROTARY DRIER

I tern

Land and site preparationRoads and parking areasBuildingsEquipment, manufacturing

CuttersDriersVibrating screenBlowerConveyor, screwConveyor, beltBagging headsPiping, cyclonesScales, hand tools, and small too

StackerErection of equipment, manufacturing

Piping and ductworkLighting, installedPower, installedTransportation facilitiesFreight on equipmertOffice furniture and fixtures

Contingenci es

Engineering fees

Total fixed capital

Working capital

Case a Case b

oOU <fr- /2~i C\oil)

o, pUU oUUV) "IOC.r j.lr.5 7, 175

2, 340 2, 340Go, DID 38, DID

o, tou370 370

745 7451:,550 1, 550

30 30170 170

125 125

580 580

11, 965 9, 570

240 240

1, 215 1,075

5.,000 4 , 225

2, 600 2,600960 960

740 215

8, 530 7, 480

15, 990 11, 225

106,620 93,530

15,000 15,000 12,000 12,000

Total capital 121, 620 105, 530

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Vegetable waste

Drier, type

Inlet air temperature, °F ;

Exit air temperature, °f.

Drier, size external drum, feet

Drier, total capacity, lbs. water evap. per nr.

Drier, total capacity, tons as is meal per 24 hours

Drier, total capacity, tons waste per 24 hours

Powe r fo r d ry i ng

Power for cutter, screen, conveyor, and fan

Moisture in waste to drier, %

Moisture in whole dried waste, %

Moi stu re in meal , %

or \ 3

Lbs. meal (m.f.b.) per lbs, waste im.f.bj

Lbs. as is meal per lbs. fresh waste

Lbs. water evap, per gal. oil

Gals, oil per ton as is meal

Gals, gasoline per ton as is meal

TABLE VN

ENGINEERING DATA FOR COST ESTIMATES 2

Pea Vines

I Portable 2 Fixed

1030

293

7 x 16

1854

3-84

31.60

Gasol i ne

Gascl i ne

78.8

25. 5

9.0

53

.122

80.0

145

10.95

1030

8 X 24

59 40

12.3

99 . 5

Elec.

El ec.

78,8

25. 5

9.0

Lima bean vines

I Portable 2 Fixed

1040 1040

53

122

95.8

121

290

7 x 16

2166

4, 37

37. 44

Gasol i ne

Gasol i ne

76.

21.6

6 . 1

, 46

, 117

93. 4

127

9.6

8 x 24

6960

14. 1

120

El ec,

Elec.

76 .

21.6

6 , 1

. 46

. 117

112.

105. 5

1 Total days' operation for all wastes combined - Portable drier, 1U0 days; fixed drier 150 days.

2 For maximum capacity of screen, assume 60 bounds her hour ber smare foot.

Moisture-free basts.

Broccol

i

Portable 2 Fixed

Spinach

I Portable 2 Fixed

Beet tops

I Portable 2 Fixed

Broccol i stems

Portable 2 Fixed

1090

336

7 x 16

1657

1.64

23- 16

Gasol i ne

Gasol i ne

90 .

28.9

5.8

.67

.071

71.4'

340

25. 6

1090

8 X 24

5320

5.3

74. 5

El ec.

El ec.

90 .0

28.9

5.8

.67

.071

85.8

281

1225

331

7 x 16

2167

2.80

28 . 80

Gasol i ne

Gasol i ne

90 . 7

4.3

4.

1

1,00

.097

78.2

238

15.0

1225

8 X 24

6960

9.0

92. 5

El ec.

El ec.

90. 7

4.3

4. 1

1.00

= 097

87.0

213

1035

330

7 x 16

1466

1. 53

19. 80

Gasol i ne

Gasol i ne

90. 4

13.9

3-4

.78

.0 77

63. 2

36 4

27. 5

1035

8 X 24

47 40

5.0

64

Elec.

El ec,

90 . 4

13.9

3- 4

. 78

.077

76.4

296

1200

7 x 16

2375

31. 4

60

Gasol i ne

Gasol i ne

52. 9

10.0

1.00

. 524

85,8

21= 2

1.3

1200

8 X 24

7580

100. 5

19 2

El ec.

El ec.

52.9

10.

1.00

. 524

94.8

19. 1

- 8 -

As previously pointed out, the carotene contents of the leaf meals givenhere are somewhat lower than would be expected in commercial processing offreshly harvested waste. Nevertheless, most of the meals are richer thanalfalfa meal, which is sold on a guaranteed basis of 133 p o p o m of caroteneand 17 percent protein (Table II) , With alfalfa meal of the guaranteedcomposition mentioned above selling in the Philadelphia market at from $53to $86. per ton, it is apparent that the production of certain vegetable leafmeals by the methods described here can be a profitable enterprise in suchan area.

Leaf meals, such as broccoli, spinach and beet tops are so rich in carotene,

xanthophyll, chlorophyll and other chemical constituents7it is probable

that they may be used to greater advantage as an industrial source of these

chemicals or as a source of one or more ingredients in special feeds*