Parenthesis refers to equipment used (see Table

cook Drain and cbol t o 3 8 C

M i x

w i t h mold inqculum

t

(E-6) Spread on d r y e r t r a y s (E-3)

t

Cover w i t h a s h e e t of waxed paper

t

Incubate a t 38 C (75-85% R H ) f o r 1 8 hours

t

Tempe

Dehydrate (E-3)

Package i n p l a s t i c bags

781 g dry tempe

(78.1% recovery o f s t a r t i n g so1 i d s )

21 .9% t o t a l sol i d s l o s s

T a b l e 1 . Equipment l i s t f o r s m a l l f a c t o r y p r o d u c t i o n o f tempe (20

F e r r e l , A. T .

,

Co.. Saginaw, Michigan. Model 297-AS C l i p p e r pea s i z e g r a d e r . S c r e e n s w i t h oblong c r o s s s l o t s 4 . 8 , 5 . 2 , 5 . 6 and 6 . 0 by 19 mm (12164, 13/64, 14/64, 15/64 by 314 i n c h )

( c a p a c i t y a b o u t 110 k g l h o u r ) .

Bauer Bros. Co., S p r i n g f i e l d , Ohio. No. 148-2-E. Twenty-one cm ( 8 i n c h ) 1 a b o r a t o r y m i l l .

C u s t o m - b u i l t c i r c u l a t i n g h o t - a i r c a b i n e t d r y e r d e s i g n e d and b u i l t by Dept. o f Food S c i e n c e and Technology, New York S t a t e A g r i c u l t u r a l Experiment S t a t i o n , Geneva, New York, w i t h con-

t r o l l e d wet-bul b t e m p e r a t u r e , a i r v e l o c i t y , and r e c i r c u l a t i o n . The d r y e r a c c e p t s t r a y s o f 35 x 81 x 1 . 3 cm ( 1 4 x 32 x 112 i n c h ) . The t r a y s a r e s t a i n l e s s s t e e l w i t h woven 3 mm (118 i n c h ) mesh bottoms.

O l i v e r Mfg. Co., Rocky Ford, Colorado. Model 5A g r a v i t y s e p a r a t o r ( c a p a c i t y 90 kglhour )

.

Lee Metal P r o d u c t s Co., I n c . , P h i l i p s b u r g , Pa. S e r i a l No.

5598. S e v e n t y - s i x l i t e r ( 2 0 g a l l o n ) s t a i n l e s s - s t e e l steam k e t t l e ( c a p a c i t y 2 8 kg h y d r a t e d b e a n s ) .

Hobart Mfg. Co., Troy Ohio. Mixer Model H-600T ( c a p a c i t y 14 kg h y d r a t e d b e a n s ) .

F i t z p a t r i c k , W . J . Co., Chicago 7, 111. Model D comninuting machine.

American S t e r i l i z e r Co., E r i e , Pa. Autoclave, t y p e LS 2138.

F. J . Stokes Machine Co., P h i l a d e l p h i a 20, Pa. F r e e z e - d r y e r , model 2004L3.

Quaker C i t y Mill Co., P h i l a d e l p h i a , Pa. Burr mill F No. 4 .

F a s t - C o o k i n g Foods

F i g u r e 4 . FLOW SHEET: I n d o n e s i a n p r o c e s s f o r oncom p r o d u c t i o n

These i n d i g e n o u s f e r m e n t e d food p r o c e s s e s o f f e r a u n i q u e o p p o r t u n i t y f o r i n c r e a s i n g t h e q u a n t i t y and q u a l i t y o f p r o t e i n i n a r e a s o f t h e w o r l d where t h e s t a p l e food i s c o m p r i s e d l a r g e l y o f s t a r c h .

SUMMARY

The A s i a n s have p r o v i d e d t h e r e s t o f t h e w o r l d p a t t e r n s by which l i g n o - c e l l u l o s i c and food p r o c e s s i n g w a s t e s c a n be c o n v e r t e d t o human food e i t h e r t h r o u g h t h e p r o d u c t i o n o f mushrooms o r

t h r o u g h f e r m e n t a t i o n by s e l e c t e d e d i b l e molds. A s t h e w o r l d

p o p u l a t i o n i n c r e a s e s t o 6 b i l l i o n o r more o v e r t h e n e x t 50 y e a r s , t h e s e p r o c e s s e s and t h o s e t h a t c a n b e d e r i v e d from them w i l l become i n c r e a s i n g l y i m p o r t a n t i n f e e d i n g t h e human r a c e .

REFERENCES

Brown, L.R., and E.P. Eckholm. The Changing Face of Global Food Scarcity. Social Ed.

-

38: 640, 1974.

Chang, S.T. The Chinese Mushroom (Volvariella vo1vacea)- Morphology, Cytology, Genetics, Nutrition and

Cultivation. The Chinese University of Hong Kong Press, 1972.

Chang, S. T. Cultivation of the straw mushroom (Volvariella volvacea). UNESCO/UNEP/ICRO/CSCHK/CUHK Regional

Training Course on Cultivation of Edible Fungi (Mushrooms) Laboratory Manual. The Chinese University of Hong Kong Press, 1977.

Cronk, T.C., K.H. Steinkraus, L.R. Hackler and L.R. Mattick.

Indonesian tap& ketan fermentation. Appl. Environ.

Microbial. -

33: 1067, 1977.

Eger, G., G. Eden, and E. Wissig. Pleurotus ostreatus

-

Breeding potential of a new cultivated mushroom. Theoret.

Appl. Genet.

-

47: 155, 1976.

Hayes, W.A. Edible Mushrooms. In: Food and Beverage Mycology.

L.R. Beuchat (ed.) Avi Publishing Co., Westport, CT. 1978, pp. 301-333.

Hesseltine, C.W., M. Smith, D. Bradle, and K.H. Djien,

Investigations of tempeh, an Indonesian soybean food. Dev.

Ind. Microbiol.

-

4: 275, 1963.

Iljas,

N.,

and A.C. Peng. Tempe kedele, an Indonesian fermented soybean food. Symposium on Indigenous Fermented Foods

(SIFF) Bangkok, Thailand, Nov. 21-27. 1977.

Jones, R.R. Editorial: 1,000 Million Dollars Every Day.

van Veen, A.G. and G. Schaefer. The influence of the tempeh fungus on the Soya bean. Doc. Neer. Indones.

Morbis Trop. - 2: 270, 1950.

van Veen, A.G., D.C.W. Graham and K.H. Steinkraus.

Fermented' peanut press cake. Cereal Sci. Today - 13 _: 96, 1968.

van Veen, A.G. and K.H. Steinkraus. Nutritive value and wholesomeness of fermented foods. Agric. Food Chem.

18: 576, 1970.

-

Wang, H.L., and C.W. Hesseltine. Wheat tempeh. Cereal Chem. 43: 563, 1966.

-

Wells, J. Analysis of potential markets for single-cell proteins. Paper presented at the Symposium on Single- cell protein, ArnericanChemical Society Annual Meeting, Philadelphia, Pa. April 9 , 1975.

Yokotsuka, T. Aroma and flavor of Japanese soy sauce.

In: Advances in Food Research, Vol. 20, Academic Press, New York, 1960, pp. 75-134.

GREEN CROP FRACTIONATION

-

AN ECONOE'IIC ANALYSIS S.B. Heath, R.J. Wilkins, A. Windram, and P.R. Foxell

IWTRODUCT ION

The reported economic analyses for the process of green crop fractionation have been for systems where all the products were intended for inclusion in animal feeds. Vosloh et a1 (1976) in the United States of America (USA) made a theoretical economic evaluation of a factory operation and that study has been updated by Enochian et a1 (1977). Bray (1977) has also evaluated this process for the USA.

In a previous study, Wilkins et a1 (1977a:131-142, 1977b:109) evaluated a number of possible systems for green crop fractionation under the economic conditions pertaining to the United Kingdom (UK).

Unlike the USA studies, no economic value was attributed to the xanthophyll in the leaf protein concentrate (LPC). This paper

extends that analysis to take account of our improved understanding of the input output relationships in the light of new research

results, the possibility of making substantial reductions in fuel usage by recycling the exhaust gases of the crop drier and, thirdly, the financial value of the xanthophyll contained in the LPC.

As in our previous study, a factory operation was modeled in which the crop was purchased at the factory gate and the products were sold to the animal feed trade. In this analysis the income, costs and returns on capital for various feasible green crop

fractionation systems are examined in relation to conventional green crop dehydration and a system of green crop dehydration

involving substantial fuel economy. The economic variables relate to those ruling in the UK in April, 1978. The sensitivity of the results is examined in relation to variation in costs and

efficiency of the process. The prospects for the commercial adoption of green crop fractionation are discussed.

DEFINITION OF TERMS

An o u t l i n e o f t h e p r o c e s s o f g r e e n c r o p f r a c t i o n a t i o n i s shown i n F i g u r e 1 . The j u i c e i s t h e c e l l s a p e x t r a c t e d f r o m t h e c r o p w i t h o u t f u r t h e r s e p a r a t i o n . The p r e s s e d c r o p i s t h e r e s i d u e

r e m a i n i n g a f t e r t h e j u i c e f r a c t i o n h a s b e e n m e c h a n i c a l l y e x t r a c t e d from t h e whole c r o p . The l e a f p r o t e i n c o n c e n t r a t e (LPC) i s t h e p r o t e i n - r i c h f r a c t i o n r e c o v e r e d from t h e j u i c e . The j u i c e f r a c t i o n r e m a i n i n g i s t e r m e d t h e d e p r o t e i n i z e d j u i c e ( D P J ) . The e x t r a c t i o n r a t i o (ExR) d e f i n e d t h e p r o p o r t i o n o f t h e c r o p d r y m a t t e r (DM) which i s e x t r a c t e d i n t h e j u i c e . L i k e w i s e t h e s e p a r a t i o n r a t i o

(SpR) i s t h e p r o p o r t i o n o f t h e j u i c e DM r e c o v e r e d a s LPC.

CROP

P R E ~ S E D

CROP

+ESH

JUICE

COAGULATED

I

JUICE

JUICE PROTEIN

(DPJ CONCENTRATE

1, 1:

~ ; P + R A T ~ FR(SH DPJ

O R E D DRIED

PRESSED P R W E D CROP

+

CRdP EVAPORATED DPJ

F i g u r e 1 . The f l o w d i a g r a m f o r t h e g r e e n c r o p f r a c t i o n a t i o n s y s t e m s .

A i n d i c a t e s p r o p o r t i o n a l f l o w ; ExR, i n d i c a t e s e x t r a c t i o n r a t i o ; SpR, i n d i c a t e s s e p a r a t i o n r a t i o .

SYSTEXS EXAMINED

The f o l l o w i n g s y s t e m s , d e f i n e d by t h e p r o d u c t s o f t h e p r o c e s s , have been compared i n t h e p r e s e n t economic e v a l u a t i o n . I n a l l c a s e s 1 0 k t a l f a l f a DM were p r o c e s s e d p e r . annum.

System 1 : D r i e d c r o p o b t a i n e d from c o n v e n t i o n a l g r e e n c r o p d e h y d r a t i o n i n which t h e e x h a u s t g a s e s from t h e d r i e r w e r e r e c y c l e d a s an a i d t o f u e l economy.

System 2 : D r i e d c r o p o b t a i n e d from a s y s t e m i n which t h e incoming c r o p was h e a t t r e a t e d and p r o c e s s e d p r i o r t o d e h y d r a t i o n

( F i g u r e 2 ) . T h i s s y s t e m w i l l be r e f e r r e d t o a s g r e e n c r o p d e h y d r a t i o n w i t h s t e e p i n g . The r e c y c l e d DPJ was h e a t e d and

r e t u r n e d t o t h e incoming c r o p s o a s t o c o a g u l a t e t h e p r o t e i n w i t h i n t h e c r o p i t s e l f . Some DPJ was removed from t h e s t e e p e d c r o p by a f i l t e r p r i o r t o f u r t h e r s e p a r a t i o n of t h e DPJ i n a s c r e w p r e s s . The DPJ i n e x c e s s o f t h a t which was r e q u i r e d f o r r e c y c l i n g was e v a p o r a t e d t o 5 0 % DM and r e t u r n e d t o t h e p r e s s e d c r o p p r i o r t o d e h y d r a t i o n . F u e l economy was a c h i e v e d by r e c y c l i n g t h e e x h a u s t g a s e s o f t h e d r i e r t h r o u g h t h e d r i e r i t s e l f and t h r o u g h t h e

e v a p o r a t o r . N e a r l y a l l t h e e n e r g y f o r t h e DPJ e v a p o r a t o r was p r o v i d e d by t h e e x h a u s t g a s e s .

CROP

HEATED RECICLZD

0 PJ STtrTED

C i i O P

I

-

7 I

PRESSED OPJ

C30P

EVAPGRATCR I I

EVAPORATE^ ^3PJ DRIED CqOP

C

F i g u r e 2 . The f l o w d i a g r a m f o r g r e e n c r o p d e h y d r a t i o n w i t h s t e e p i n g , System 2 .

Three g r e e n c r o p f r a c t i o n a t i o n s y s t e m s were e v a l u a t e d : System 3 : D r i e d p r e s s e d c r o p and c o a g u l a t e d j u i c e .

System 4 : D r i e d p r e s s e d c r o p w i t h e v a p o r a t e d DPJ r e t u r n e d

t o t h e p r e s s e d c r o p a n d d r i e d LPC.

System 5 : D r i e d p r e s s e d c r o p , d r i e d LPC a n d f r e s h DPJ r e t u r n e d t o t h e l a n d a s f e r t i l i z e r .

F o r t h e s e s y s t e m s t h e c r o p was p u l p e d p r i o r t o p r e s s i n g w i t h a screw p r e s s . The j u i c e was c o a g u l a t e d w i t h s t e a m , a n d , when s o l d a s c o a g u l a t e d j u i c e , h y d r o c h l o r i c a c i d and sodium m e t a b i - s u l p h i t e w e r e a d d e d a s p r e s e r v a t i v e s . The LPC was r e c o v e r e d u s i n g a d e c a n t e r c e n t r i f u g e and d r i e d i n a f l u i d i z e d - b e d d r i e r . Where t h e D P J was r e t u r n e d t o t h e p r e s s e d c r o p i t was f i r s t e v a p o r a t e d t o 50% DM i n a m u l t i p l e - e f f e c t e v a p o r a t o r u s i n g t h e e n e r g y d e r i v e d f r o m t h e e x h a u s t g a s e s o f t h e c r o p d r i e r . Where t h e DPJ was r e t u r n e d t o t h e l a n d t h e h e a t c o n t a i n e d i n t h e DPJ was r e c o v e r e d t o p r e h e a t t h e w a t e r u s e d t o p r o d u c e s t e a m . The d r i e d p r e s s e d c r o p was g r o u n d and p e l l e t e d b e f o r e s a l e .

THE PRINCIPAL ASSUMPTIONS I N THE MODEL

The f u l l l i s t i n g o f t h e a s s u m p t i o n s and t h e d a t a u s e d c a n b e o b t a i n e d from t h e f i r s t a u t h o r . O u t l i n e d below a r e t h e most

i m p o r t a n t f e a t u r e s o f t h e model; t h e d e t e r m i n a t i o n o f ExR, t h e s a l e p r i c e o f t h e p r o d u c t s , t h e p u r c h a s e p r i c e o f t h e c r o p a n d t h e m a c h i n e r y c o s t s

..

The more e f f i c i e n t t h e p r o c e s s o f p u l p i n g p r i o r t o p r e s s i n g t h e g r e a t e r w i l l b e E x R . T h e r e i s a l s o a n e g a t i v e r e l a t i o n s h i p between ExR a n d t h e c r o p DM p e r c e n t . I n t h e a n a l y s i s o f t h e g r e e n c r o p f r a c t i o n a t i o n s y s t e m s i t was assumed t h a t a n 18% DM c r o p

was p r o c e s s e d t o g i v e a n ExR o f 0.36 f o r c r o p s p u l p e d p r i o r t o p r e s s i n g , a n d 0.22 f o r u n p u l p e d c r o p s . The r e l a t i v e d r y m a t t e r y i e l d s o f t h e p r o d u c t s o b t a i n e d w i t h t h e s e E x R s a r e shown i n T a b l e 1 .

T a b l e 1 . The r e l a t i v e d r y m a t t e r y i e l d s o f t h e p r o d u c t s from t h e p r o c e s s o f g r e e n c r o p f r a c t i o n a t i o n .

E x t r a c t i o n r a t i o

c r o p 1 100 100

J u i c e : 36 2 2

LPC 16 8

D P J 20 14

P r e s s e d Crop 64 78

'

18 percent DM crop processed.

The basis for the calculation of the sale price of the products was their calculated content of metabolizable energy

(ME)

and digestible crude protein (DCP). It was assumed that the total production of ME and DCP was the same for all systems. The composition of the various products is shown in Table 2 and their economic values are shown in Table 3. The values of IdE and DCP per unit were derived from the UK market prices of barley and

soybean meal and their content of ME and DCP. In addition, the content of xanthophyll in the LPC increased this product's value.

The value of a unit of xanthophyll was related to the cost of synthetic xanthophyll. The market price of coagulated juice was

1 0 % lower than the price related directly to its nutritional value

to allow for the greater difficulty in storing, transporting and utilizing such a product. The fresh DPJ was valued on the basis of its fertilizer value reduced by the cost of returning it to the land.

Table 2. The composition of the products from the process of green crop fractionation

Ektraction ratio 0.36 Extraction ratio 0.22

b P 180 195 9.6 144

-

^{180 195 9.6 144}

-

Juice 92 350 11.6 287

-

^{76 320 11.6 259}

-

LPC

-

613 12.4 531 1.30

-

^{617 12.4 534 1.31}

DPJ 57 150 11.0 102

-

51 142 11.2 95

-

Pressed

CJlOp 322 107 8.4 62

-

266 159 9.0 110

-

~ r y

matter.

'

Crude protein.

Metabolisable energy.

Digestible crude protein.

Xanthophyll.

The purchase price of the fresh alfalfa was calculated to qive the farmer a qross marqin (income minus the direct costs of production) simila; to that-obtained from the production of barley grain. The calculation involved the yields and direct production costs for alfalfa and barley, and the- sale price of barley.

Harvesting and transport of the crop to the factory gate were considered as separate contract operations. In costing these operations allowance was made for the contractor's own return on capital.

T a b l e 3. The s a l e v a l u e ( e x f a c t o r y ) o f t h e p r o d u c t s f r o m t h e

No a l l o w a n c e was made f o r t h e i n t e r e s t on t h e s e t - u p c a p i t a l

T a b l e 4. C a l c u l a t e d income a n d c o s t s (Ek) a n d p e r c e n t a g e r e t u r n

T h i s r e s u l t e d i n a s m a l l i n c r e a s e i n r e t u r n o n c a p i t a l ( T a b l e 5 )

S e n s i t i v i t y o f t h e R e t u r n t o V a r i a t i o n i n Income

The v a l u e o f t h e x a n t h o p h y l l c o n t a i n e d i n t h e LPC i s a l s o o f

I

^{1 I 1}

220

240

2 60

PERCENT CHANGE IN FACTOR

F i g u r e 3A. The e f f e c t o f a p e r c e n t a g e change i n t h e v a l u e o f c e r t a i n f a c t o r s which r e s u l t s i n a p o s i t i v e change i n t h e p e r c e n t a g e r e t u r n on c a p i t a l f o r g r e e n c r o p f r a c t i o n a t i o n , System 4 , p r o d u c i n g d r i e d p r e s s e d c r o p w i t h r e t u r n e d e v a p o r a t e d DPJ and d r i e d LPC.

The f a c t o r s a r e a l f a l f a DM y i e l d p e r h e c t a r e (DMY), f a r m e r ' s g r o s s margin p e r h e c t a r e ( F G r l ) , p o t e n t i a l number o f o p e r a t i o n a l weeks p e r annum (WEEKS) and s e t - u p c a p i t a l (CAP). P o i n t A r e p r e s e n t s z e r o c o s t o f t h e p u l p e r and p r e s s , p o i n t B p a r t i a l s h a r i n g o f t h e s e t - u p c a p i t a l w i t h a n o t h e r p r o c e s s and p o i n t C a c a p i t a l g r a n t o f 33%.

System 4 System 5

syst em 1

I ^{1 I 1}

4 8 12

COST OF N E L p/ l i t i a

F i g u r e 3 B . The e f f e c t o f t h e c o s t o f f u e l on t h e p r o f i t a c h i e v e d by v a r i o u s g r e e n c r o p d e h y d r a t i o n and g r e e n c r o p

f r a c t i o n a t i o n s y s t e m s . System 1 i s c o n v e n t i o n a l g r e e n c r o p d e h y d r a t i o n w i t h g a s r e c y c l i n g . System 2 i s

g r e e n c r o p d e h y d r a t i o n w i t h s t e e p i n g (see t e x t f o r d e t a i l s ) . S y s t e m 4 g r e e n c r o p f r a c t i o n a t i o n p r o d u c i n g d r i e d p r e s s e d c r o p w i t h r e t u r n e d e v a p o r a t e d DPJ and d r i e d LPC. S y s t e m 4 G , a s System 4 b u t w i t h no e x h a u s t g a s e s r e c y c l e d f r o m t h e d r i e r t o t h e e v a p o r a t o r .

System 5 g r e e n c r o p f r a c t i o n a t i o n p r o d u c i n g d r i e d p r e s s e d c r o p d r i e d LPC and f r e s h DPJ. C o s t o f f u e l f o r s t a n d a r d r u n s 8 p / l i t r e .

s i m i l a r t o a l f a l f a would b e a v a i l a b l e .

T a b l e 7. The p e r c e n t a g e r e t u r n on c a p i t a l f o r t h e s y s t e m s u n d e r s e l e c t e d p r i c i n g s i t u a t i o n s .

No subsidv Pfus subsidv

System 1 Conventional green crop dehydration m g 26

System 2 Green crop dehydration w i t h steeping 7 2 9

System 3 Dried pressed crop and coagulated juice

System 4 Dried pressed crop with returned evaporated DPJ, and dried LPC Xanthophyll E O / t

LeC

Xanthophyll E45/t LeC

Xanthophyll E193/t LPC

System 5 Dried pressed crop, dried LPC and fresh DPJ (ExR = 0.36)

Xanthophyll E O / t

LeC

Xanthophyll E193/t

LeC

NEG NEG

3 2 35

~ ~ ~~

l ExR

-

Extraction r a t i o .

i n s e t - u p c a p i t a l t o a l a r g e e x t e n t n e g a t e t h e a d v a n t a g e s i n f u e l economy e s p e c i a l l y when no v a l u e i s a t t r i b u t e d t o t h e x a n t h o p h y l l c o n t e n t o f t h e LPC.

With no s u b s i d y payment and t h e h i g h e s t v a l u e p l a c e d on x a n t h o p h y l l t h e r e was c o n s i d e r a b l e a d v a n t a g e t o b e g a i n e d from System 4 r a t h e r t h a n from e i t h e r o f t h e c r o p d e h y d r a t i o n s y s t e m s . A s E n o c h i a n e t a 1 ( 1 9 7 7 ) a l s o c a l c u l a t e d , t h e r e t u r n on c a p i t a l u n d e r t h e s e p r i c e c i r c u m s t a n c e s i n c r e a s e d w i t h i n c r e a s i n g E x R b e c a u s e o f t h e v a l u e added by t h e x a n t h o p h y l l c o n t e n t o f t h e LPC.

The h i g h e s t v a l u e t h a t c o u l d b e a t t r i b u t e d t o t h e x a n t h o p h y l l i n t h e LPC i n t h e UK i n A p r i l 1978 was E193/tonne LPC DPI b u t a s a l r e a d y a r g u e d , t h e v a l u e i n t h e UK i s l i k e l y t o b e o n l y a r o u n d E45/tonne LPC DM. A s a r e s u l t t h e a d v a n t a g e o f System 4 was removed a n d c r o p d e h y d r a t i o n w i t h s t e e p i n g , System 2 , was m a r g i n a l l y more a t t r a c t i v e .

W i t h a s u b s i d y e q u i v a l e n t t o t h a t r e c e i v e d b y p r o d u c e r s i n t h e

SUMMARY

A t h e o r e t i c a l model h a s been c o n s t r u c t e d i n which income,

c o s t s and r e t u r n on s e t - u p c a p i t a l have been c a l c u l a t e d f o r f a c t o r y s c a l e s y s t e m s o f g r e e n c r o p d e h y d r a t i o n and g r e e n c r o p f r a c t i o n a t i o n . The r e t u r n s from t h e s e s y s t e m s a r e compared and t h e s e n s i t i v i t y

o f t h e r e s u l t s t o v a r i a t i o n i n p r o d u c t income, p r o d u c t y i e l d and c e r t a i n c o s t i t e m s i s a n a l y z e d . S u b s t a n t i a l f u e l economy c a n be a c h i e v e d by a d o p t i n g a m o d i f i e d g r e e n c r o p d e h y d r a t i o n s y s t e m i n v o l v i n g p r e t r e a t m e n t o f t h e c r o p p r i o r t o d r y i n g and by s y s t e m s o f g r e e n c r o p f r a c t i o n a t i o n . The r e t u r n on s e t - u p c a p i t a l a c h i e v e d by s y s t e m s o f g r e e n c r o p f r a c t i o n a t i o n p r o d u c i n g l e a f p r o t e i n

c o n c e n t r a t e i s p a r t i c u l a r l y s e n s i t i v e t o t h e v a l u e o f t h e pigment x a n t h o p h y l l . I t i s c o n c l u d e d t h a t w i t h o u t a h i g h v a l u e b e i n g a t t r i b u t e d t o t h e x a n t h o p h y l l t h e p r o s p e c t s f o r t h e commercial e x p l o i t a t i o n o f g r e e n c r o p f r a c t i o n a t i o n t o p r o d u c e a n i m a l f e e d s i n t h e U n i t e d Kingdom a r e n o t e n c o u r a g i n g a t p r e s e n t .

Un modsle th6orique a 6t6 construit, consistant

2

calculer le revenu, les cocts et les profits d'un capital pour un grand nombre de systsmes de fractionement de plantes fourragsres placgs dans des situations 6conomiques trss diverses. Les systsmes

varient des productions simples de jus coagul6 pour l'alimentation des porcs et de fourrages fraechement press6s pour l'alimentation des ruminants, aux proc6d6s de fabrication sophistiqu6s produisant des concentr6s de prot6ines de feuilles sgch6es et des plantes

fourragsres s6ch6es auxquelles sont ajoutges du jus d6prot6inis6.

Ce travail examine en dgtail le rgsultats consid6r6s comrne gtant possibles de certains de ces systsmes ngcessitant des proc6d6s de fabrication annuels de l'ordre d'au moins 10 kt de matisre s6ch6e.

Ces rgsultats sont compargs avec ceux calcul6s pour le sgchage conventionnel de plantes fourrag&res utilisant divers proc6d6s de rgutilisation de la chaleur.

REFERENCES

B r a u d e , R . , A.S. J o n e s , a n d R.A. Houseman. 1977. I n Green Crop F r a c t i o n a t i o n , e d i t e d .by-R.J. Wilkins. P a g e s 47-55. O c c . Symp.No. 9 , B r i t . G r a s s l a n d S o c i e t y .

B r a y , W . J . 1977. A C o n s i d e r a t i o n o f t h e Economics o f Green Crop F r a c t i o n a t i o n and Leaf P r o t e i n P r o d u c t i o n . P a p e r p r e s e n t e d i n B r a z i l t o t h e workshop " U t i l i z a t i o n o f A g r i c u l t u r a l W a s t e s " . Page 9.

E n o c h i a n , R . V . , R.H. Edwards, D.D. Kuzmicky, a n d G . O . K o h l e r .

1977. P r o t e i n C o n c e n t r a t e (Pro-Xan) from A l f a l f a : a n Updated Economic E v a l u a t i o n . American S o c i e t y o f A g r i c u l t u r a l

E n g i n e e r s . P a p e r no. 77-6538. Page 23. W i n t e r F l e e t i n g . K o e g e l , R . G . , and H . D . Bruhn. 1977. I n Green Crop F r a c t i o n a t i o n ,

e d i t e d by R . J . W i l k i n s . O c c . Sump. N o . 9 , B r i t . G r a s s l a n d S o c i e t y . P a g e s 23-28.

V o s l o h , C . J . , R.H. Edwards, R.V. E n o c h i a n , D.D. Kuzmicky, a n d G . O . K o h l e r . 1976. Leaf P r o t e i n C o n c e n t r a t e (Pro-Xan) f r o m A l f a l f a : a n Economic E v a l u a t i o n . N a t i o n a l Economic A n a l y s i s D i v i s i o n , Economic R e s e a r c h S e r v i c e , U.S. D e p a r t m e n t o f

A g r i c u l t u r e , A g r i c u l t u r a l Economic R e p o r t No. 346.

W i l k i n s , R . J . , S.B. H e a t h , W.P. R o b e r t s , and P.R. F o x e l l . 1977a..

Green Crop F r a c t i o n a t i o n , e d i t e d by R . J . W i l k i n s . P a g e s 131-142. O c c . Symp. No. 9 , B r i t . G r a s s l a n d S o c i e t y . W i l k i n s , R . J . , S.B. H e a t h , W.P. R o b e r t s , P . R . F o x e l l , and A.

Windram. 1977b. G r e e n Crop F r a c t i o n a t i o n : An Economic A n a l y s i s . Page 109. T e c h n i c a l R e p o r t No. 19. G r a s s l a n d R e s e a r c h I n s t i t u t e , England.

ACKNOWLEDGEMENTS

W e g r a t e f u l l y acknowledge t h e h e l p g i v e n t o u s by many p e o p l e i n p r o v i d i n g d a t a f o r t h i s model. I n p a r t i c u l a r w e t h a n k D r . T.R.

M o r r i s ( U n i v e r s i t y o f R e a d i n g ) f o r h i s c o l l a b o r a t i o n w i t h t h e l e a s t c o s t r a t i o n f o r m u l a t i o n a n a l y s i s o f t h e v a l u e of LPC i n p o u l t r y r a t i o n s . One o f t h e a u t h o r s (S.B. H e a t h ) g r a t e f u l l y acknowledges t h e s u p p o r t o f t h e Wolfson F o u n d a t i o n .

PROTEIN AND FAT RECOVERY FROM

FOOD PROCESS EFFLUENTS

R.A. G r a n t

Waste e f f l u e n t s from meat, p o u l t r y and f i s h p r o c e s s i n g p l a n t s c o n t a i n l a r g e amounts o f p r o t e i n and f a t and u s u a l l y have much h i g h e r v a l u e s o f b i o c h e m i c a l oxygen demand ( B . O . D . ) t h a n town sewage. Such e f f l u e n t s a r e h i g h l y p o l l u t i n g and c a n impose heavy l o a d s on p u b l i c sewage t r e a t m e n t works.

I t h a s been e s t i m a t e d t h a t between 2 and 5% o f t h e t o t a l c a r c a s e p r 0 t e i n . i ~ l o s t i n t h e e f f l u e n t s from a b a t t o i r s and p o u l t r y p r o c e s s i n g p l a n t s . I n t h e U . K . t h i s amounts t o t e n s o f t h o u s a n d s o f t o n n e s p e r annum w i t h a p o t e n t i a l v a l u e a t p r e s e n t i n t h e r e g i o n o f £ 2 0 0 p e r t o n n e , f o r t h e world a s a whole, t h i s l o s s n e e d s t o b e m u l t i p l i e d by a f a c t o r o f a b o u t 100. A t t h e p r e s e n t t i m e when w o r l d p o p u l a t i o n i s i n c r e a s i n g r a p i d l y and

o u t s t r i p p i n g f o o d p r o d u c t i o n i n many a r e a s s u c h a w a s t a g e i s h a r d t o j u s t i f y i f t h e means of p r e v e n t i n g it a r e a v a i l a b l e .

C o n v e n t i o n a l b i o l o g i c a l e f f l u e n t t r e a t m e n t p l a n t s s u f f e r

from t h e i n h e r e n t d i s a d v a n t a g e t h a t p o t e n t i a l l y v a l u a b l e m a t e r i a l s s u c h a s p r o t e i n and f a t a r e d e g r a d e d t o u s e l e s s s l u d g e which i n i t s e l f p r e s e n t s a d i s p o s a l problem. On t h e o t h e r hand, i n t h e case o f p h y s i c o - c h e m i c a l t r e a t m e n t p l a n t s d e s i g n e d t o r e c o v e r f a t and p r o t e i n t h e r e v e n u e from t h e s a l e o r r e c y c l i n g o f b y - p r o d u c t s c a n b e u s e d t o d e f r a y e i t h e r i n whole o r p a r t , t h e c a p i t a l and r u n n i n g c o s t s o f t h e p l a n t .

I n t h e p a s t , v a r i o u s p r o c e s s e s h a v e been p r o p o s e d i n v o l v i n g t h e u s e o f c h e m i c a l p r e c i p i t a n t s t o remove p r o t e i n from s o l u t i o n . These have u s u a l l y employed t o x i c compounds s u c h a s i r o n s a l t s which r e s u l t s i n t h e p r e c i p i t a t e d p r o t e i n b e i n g u s e l e s s f o r n u t r i t i o n a l p u r p o s e s . The Aquapure p r o c e s s a l l c w s t h e r e c o v e r y o f p r o t e i n i n a c o m p l e t e l y n o n - t o x i c form s u i t a b l e f o r f e e d i n g t o b o t h d o m e s t i c and f a r m a n i m a l s .

E f f l u e n t T r e a t m e n t

Table 1. Cbmposition of by-products recovered from slaughterhouse

-

^{7 9}

-

T a b l e 3 . E s s e n t i a l amino a c i d s ( g amino a c i d / l 6 g n i t r o g e n ) .

Amino Acid FAO* Egg Fraction Casein

Isoleucine 4.2 6.8 5.5 4 . 1 7.5

Leucine 4.8 9.0 17.1 15 .O 10.0

Lysine 4.2 6.3 8.8 8.5 8.5

Phenylalanine 2.8 6.0 9.9 7.9 6.3

Tyrosine 2.8 4.4 5.5 3.2 6.4

Threonine 2.8 5.0 7.9 4.5 4.5

Tryptophan 1.4 1.7

- - -

Valine 4.2 7.4 11.0 8.2 7.7

Sulphur containing:

Total 4.2 5.4 2.8 3.2 4.3

Methionine 2.2 3.1 2.8 3.2 3.5

*Food and Agricultural Organization 'provisional pattern' of e s ~ e n t i a l amino a c i d s f o r human nutrition; R o m e , 1 9 5 7 .

T a b l e 4 . Amino a c i d a n a l y s i s o f p r o t e i n r e c o v e r e d f r o m p o u l t r y p r o c e s s i n g p l a n t e f f l u e n t (umoles/100 u r n o l e s ) .

Aspartic acid Serine

Proline Alanine Val ine Isoleucine Tyrosine Lysine Arginine

Threonine 5.1 Glutamic acid 11.5

Glycine 6.9

Cystine (half) 1.2 Methionine 1.5

Leucine 9.1

Phenylalanine 3.8 Histidine 2.3

Tryptophan not estimated.

T a b l e 5. C h i c k g r o w t h , f o o d c o n s u m p t i o n a n d f e e d e f f i c i e n c y o f

s l i g h t l y i n f e r i o r t o f i s h m e a l b u t s u p e r i o r t o t h e meat a n d bone

Table 7, Residual BOD

( X )

in treated slaughterhouse effluent.

Sample

Treatment 1 2 5 Means

Flocculation 38 41 31 2 3 27 32 Ion exchange 1 0 13 2 3 19 18 17 Flocculation+

ion exchange

-*

^{5 12 7}

-*

⁵

-*

Value too low for measurement by standard method.

Table 8. Residual COD ( X ) in slaughterhouse effluent after treatment.

-

Sample Treatment 1 2

-

3 4 5 6 7 Means

Flocculation 19 40 31 37 35 31 31 Ion exchange 18 31 31 28 25 27 15 Flocculation+

ion exchange

-*

^{14 9 22}

-*

¹¹

-*

-*

value too low for estimation by standard method

Table 9. Reduction of chemical oxygen demand and by-product yields for poultry processing effluents.

Specimen No. 1 2 3

Chemical Oxygen demand 1; 6050 2 1150 X reduction in COD

By-product yield g/L

1 and 2l 1

-

before and after treatment

a u t h o r i t i e s f o r d i s c h a r g e t o s e w e r s , s o t h a t , d e p e n d i n g on

Im Dokument New Technologies for the Utilization of Agricultural By-Products and Waste Materials. Proceedings of a Task Force Meeting (Seite 55-92)