6 Incorporation of Cottonseed into Foods for Humans Elwood F. Reber
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Department of Nutrition and Food Sciences, Texas Woman's University, Denton, TX 76204
The Food and Drug Administration approved the use of cottonseed containing not more than 450 ppm gossypol for human use. Glandless whole kernel cottonseed flakes and cot-n-nuts are commercially available. Studies incorporating cottonseed into many different foods have yielded acceptable products with improved protein quantity and quality. The presence of free gossypol and cyclopropenoid fatty acids (CPFA) potentially limits the use of cottonseed in human foods. The levels of free gossypol and CPFA are reduced in processing the seed and preparation of food. The amount of free gossypol and CPFA in the food as eaten should be determined. The American Oil Chemists' Society method for free and total gossypol is not specific for gossypol and gave false positive readings for several food ingredients. Glandless cottonseed i s a valuable addition to the food supply in the United States. The development and utilization of glandless cottonseed in the rest of the world would be a major contribution to the alleviation of severe hunger in some areas. Glanded c o t t o n s e e d i s t h e c o t t o n c r o p grown around t h e w o r l d . The c o t t o n p l a n t and t h e c o t t o n s e e d have pigment g l a n d s which c o n t a i n s e v e r a l pigments t h a t c a n make t h e seed appear dark green t o b l a c k . One o f t h e pigments i s g o s s y p o l . C o t t o n s e e d was f i r s t s u g g e s t e d as a f o o d s o u r c e f o r human consumption i n 1876 (1). When g l a n d e d c o t tonseed i s f e d t o monogastric animals, t h e oxygen-carrying c a p a c i t y of t h e b l o o d i s reduced and s h o r t n e s s o f b r e a t h , edema o f t h e l u n g s and p a r a l y s i s may o c c u r . Rats u s u a l l y show s i g n s o f l o s s o f a p p e t i t e , d e c r e a s e d growth, rough h a i r c o a t and l i s t l e s s n e s s (2). However, t h e t o x i c e f f e c t s o f g o s s y p o l a f f e c t s v a r i o u s a n i m a l s t o d i f f e r e n t degrees o f s e v e r i t y . The C h i n e s e (3) found t h e consumption of u n r e f i n e d c o t t o n o i l by humans caused a r e v e r s i b l e i n f e r t i l i t y i n males. C o t t o n s e e d f l o u r h a s been i n c l u d e d i n INCAPARINA baby f o o d f o r m u l a s i n Guatemala (4).
0097-6156/86/0312-0061 $06.00/0 © 1986 American Chemical Society
Ory; Plant Proteins: Applications, Biological Effects, and Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1986.
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PLANT PROTEINS
Glanded c o t t o n s e e d has been used t o produce a d e f a t t e d c o t t o n seed f l o u r w i t h r e d u c e d g o s s y p o l c o n t e n t by a p r o c e d u r e known as t h e l i q u i d c y c l o n e p r o c e s s (LCP). LCP c o t t o n s e e d f l o u r has been used i n the p r e p a r a t i o n o f many foods t h a t have been t e s t e d i n s e v e r a l a n i m a l and human n u t r i t i o n s t u d i e s . The commercial p r o d u c t i o n o f LCP c o t t o n s e e d f l o u r has n o t been s u c c e s s f u l (.5) .
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S t u d i e s w i t h Raw, Cooked and Roasted
Cottonseed
G l a n d l e s s c o t t o n s e e d i s o b t a i n e d from a c o t t o n v a r i e t y t h a t has reduced amounts o f pigment and g o s s y p o l i n t h e seed k e r n e l . The f i r s t r e p o r t o f a sub-acute t o x i c i t y i n v e s t i g a t i o n o f g l a n d l e s s c o t tonseed f e d t o r a t s was made by Reber and Pyke ( 6 ) . The i n v e s t i g a t i o n was d e s i g n e d t o s a t i s f y t h e r e q u i r e m e n t s o f t h e Food and Drug A d m i n i s t r a t i o n (FDA). The r e s u l t s were s u b m i t t e d t o t h e FDA, who o b j e c t e d t o t h e v a l i d i t y o f t h e s t u d y on t h e b a s i s t h a t c o t t o n s e e d o i l was a d e r i v e d component o f c o t t o n s e e d k e r n e l s ; so t h e c o n t r o l d i e t d i d not serve i t s purpose. The FDA s u g g e s t e d t h a t a n o t h e r s t u d y be conducted where t h e r a t s would be f e d a c o n t r o l d i e t c o n t a i n i n g 6% c o r n o i l t o be a b l e t o c o n c l u d e w i t h o u t r e s e r v a t i o n t h a t g l a n d l e s s c o t t o n s e e d k e r n e l s a r e s a f e f o r human consumption, based on r a t studies. A p r o t o c o l approved by t h e FDA t o d e t e r m i n e t h e s a f e t y o f low g o s s y p o l c o t t o n s e e d k e r n e l s f o r human consumption was t h e b a s i s f o r the second s t u d y by Reber C7 ) . To p r e p a r e raw c o t t o n s e e d f l o u r , raw k e r n e l s were ground t o meet Ro-tap s i e v e s p e c i f i c a t i o n s o f l a b chow. To p r e p a r e r o a s t e d c o t t o n s e e d f l o u r , raw k e r n e l s were d r y r o a s t e d a t not l e s s than 121°C f o r n o t l e s s t h a n 5 min. To p r e p a r e cooked c o t t o n s e e d f l o u r , raw k e r n e l s were cooked i n steam u n t i l b a t c h temperat u r e had been a t o r above 121°C f o r 5 min. A l l c o t t o n s e e d k e r n e l s were ground i n t h e manner d e s c r i b e d above. The k e r n e l s c o n t a i n e d n o t more than O.037% (370 ppm) o f f r e e g o s s y p o l . They were f r e e o f S a l m o n e l l a and d i d n o t c o n t a i n d e t e c t a b l e amounts o f a f l a t o x i n . The proximate a n a l y s e s o f t h e c o t t o n s e e d f l o u r s a r e shown i n T a b l e I . The g l a n d l e s s c o t t o n s e e d was o b t a i n e d from Rogers C o t t o n s e e d Co., Waco, Texas, t h e n p r o c e s s e d and a n a l y z e d by t h e Food P r o t e i n R e s e a r c h and Development C e n t e r , Texas A&M U n i v e r s i t y , C o l l e g e S t a t i o n , Texas. Table I.
Moisture, % Protein, % Oil, % Ash, % Crude F i b e r , % Gossypol (free) % Gossypol ( t o t a l ) % Lead, ppm A r s e n i c , ppm Heavy m e t a l s , ppm
A n a l y s i s of Cottonseed Raw 6.20 39.13 35.45 4.30 1.48 O.037 O.042 1.5 O.1 10.0
Flours
Roasted 2.27 40.56 37.34 4.44 1.42 O.03 1.5 O.1 10.0
R e p r i n t e d from J . Food S c i . 1981. 46(2):593-596. I n s t i t u t e o f Food T e c h n o l o g i s t s .
C o p y r i g h t by
Ory; Plant Proteins: Applications, Biological Effects, and Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1986.
Cooked 4.23 39.81 36.94 4.39 1.37 O.034 O.034 1.5 O.1 10.0
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6.
REBER
Incorporation of Cottonseed into Foods
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Growing female r a t s u t i l i z e d cooked o r r o a s t e d c o t t o n s e e d more e f f i c i e n t l y than raw c o t t o n s e e d o r c o n t r o l d i e t . The p e r c e n t a g e s of pups a l i v e a t b i r t h s u r v i v i n g t o 4 days were s i g n i f i c a n t l y h i g h e r f o r r a t s f e d raw o r cooked c o t t o n s e e d than r o a s t e d c o t t o n s e e d . There were no s i g n i f i c a n t d i f f e r e n c e s due t o d i e t o b s e r v e d i n average body w e i g h t s of dams a t p a r t u r i t i o n and a t weaning time o r i n weight o f offspring. There were no d e t r i m e n t a l e f f e c t s due t o f e e d i n g low g o s s y p o l (370 mg/kg) c o t t o n s e e d k e r n e l s a t a l e v e l of 20% o f the d i e t e q u i v a l e n t t o 74 mg o f f r e e g o s s y p o l per kg o f d i e t as e a t e n . Rats f e d c o t t o n s e e d grew as w e l l as o r b e t t e r t h a n c o n t r o l a n i m a l s . Heat treatment o f c o t t o n s e e d a p p a r e n t l y made one o r more n u t r i e n t s more a v a i l a b l e on a n u t r i t i o n a l b a s i s t o female r a t s . O v e r a l l the d i e t c o n t a i n i n g cooked c o t t o n s e e d appeared t o be a b e t t e r d i e t than the d i e t containing roasted cottonseed. These o b s e r v a t i o n s l e d t o an i n v e s t i g a t i o n of the p r o t e i n q u a l i t y o f the c o t t o n s e e d as a f f e c t e d by the p r o c e s s i n g . The same shipment of raw, cooked and r o a s t e d g l a n d l e s s whole k e r n e l c o t t o n s e e d f l o u r s used i n t h e FDA study was used t o determine the p r o t e i n e f f i c i e n c y r a t i o (PER) of each f l o u r ( 8 ) . The a d j u s t e d PER ( T a b l e I I ) o f cooked (2.10) c o t t o n s e e d was s i g n i f i c a n t l y h i g h e r than r o a s t e d (1.77) c o t t o n s e e d . Protein retention efficiency (PRE) f o r r o a s t e d c o t t o n s e e d (58.08) was lower than v a l u e s f o r raw (60.54) and cooked (62.95) c o t t o n s e e d . R e l a t i v e p r o t e i n v a l u e s (RPV) i n d i c a t e d a u t i l i z a t i o n of 91, 91 and 96% o f the p r o t e i n i n raw, r o a s t e d and cooked c o t t o n s e e d , r e s p e c t i v e l y . The m u l t i p l i c a t i o n o f the (RPV) p e r c e n t a g e u t i l i z a t i o n and the p r o t e i n c o n t e n t o f the c o t t o n seed ( T a b l e I) r e s u l t s i n t h e r e l a t i v e u t i l i z a b l e p r o t e i n v a l u e s (Table I I ) . T a b l e I I . Average P r o t e i n E f f i c i e n c y R a t i o (PER), R e l a t i v e P r o t e i n V a l u e (RPV) and R e l a t i v e U t i l i z a b l e P r o t e i n f o r Raw, Roasted and Cooked Whole K e r n e l C o t t o n s e e d 3
Parameter (adjusted)
PER RPV Relative Utilizable Protein^ a
Casein 2.50b
R e p r i n t e d from J . Food Q u a l i t y 1983.
Raw 1.93 O.91 35.61
c
Cottonseed Roasted 1.77ce O.91 36.90
Cooked 2.10CÛ O.96 38.21
6:65-71.
^Was s i g n i f i c a n t l y (P
