Applications of Vegetable Food Proteins in Traditional Foods

sesame, and glandless cottonseed) were first accepted by man for ... (6). Heat treatment deactivates lipases and lipoxygenases ... than defatted flour...
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4 Applications of Vegetable Food Proteins in Traditional Foods

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E. W. Lusas and K. C. Rhee Food Protein Research and Development Center, Texas A & M University, College Station, TX 77843

On a world wide basis, man obtains approximately 70% of his daily protein intake from plant sources and 30% from animal and fish sources. These figures are 50 and 50%, respectively, for the developed nations, and 83 and 17% for the developing countries. Oilseeds and pulses (dry beans, lentils and peas) are concentrated sources of proteins, and are expected to play increasingly important roles in human nutrition as world population grows. Whole oilseeds and legumes and their derivatives (defatted flours, and protein concentrates and isolates) are used in traditional foods as sources of protein and for their texture-modifying functions. This article reviews, on a comparative basis, processes for preparation of vegetable food proteins, compositions and characteristics of the resulting food ingredients, and their functionalities and uses in traditional foods. The pulses and c e r t a i n oilseeds (soy, peanuts, sunflower seed, sesame, and glandless cottonseed) were f i r s t accepted by man f o r t h e i r storage s t a b i l i t y , high nutrition-to-weight r a t i o , and a t t r a c tiveness of the foods that can be made from them. Much of the current i n t e r e s t i n uses of derived o i l s e e d proteins i n compounded foods stems from projects i n the mid-1960 s t o a l l e v i a t e massive world hunger. Perhaps the best known of these was the development of Incaparina at the I n s t i t u t e f o r N u t r i t i o n o f Central America and Panama, i n Guatemala by Bressani and coworkers (1). However, many other vegetable protein-enriched mass feeding foods also have been developed, and have been reviewed {2, 3). In developing low cost mass feeding foods, attempts were made t o use l o c a l l y available o i l s e e d cakes and meals whenever possible. In time, i n t e r e s t turned t o the extraction o f high protein content ,

0097-6156/ 86/ 0312-0032$06.00/ 0 © 1986 American Chemical Society

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

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4. LUS AS A N D RHEE

Vegetable Food Proteins in Traditional Foods

33

ingredients from other processing residues and n o n t r a d i t i o n a l crops. Prejudices once existed against pulses and c e r t a i n oilseeds as foods of the poorest of the poor. However, with world-wide i n t e r e s t i n physical f i t n e s s and dietary f i b e r , and concerns about possible r e l a t i o n s between animal p r o t e i n comsumption and atherosclerosis (£, _5), i n t e r e s t i n food uses of vegetable food proteins i s increasing. Each ingredient i n a compounded food i s selected for a s p e c i f i c purpose. Even the l e s s c o s t l y , low p r o t e i n , ingredients play important roles as sources of t o t a l s o l i d s . For example, the Recommended Daily Allowance (RDA) of 65 g protein i s the equivalent of 260 calor i e s . In a 2600 c a l o r i e d i e t , t h i s amount of p r o t e i n can be d i l u t e d among a t o t a l c a l o r i c intake ten times greater. In addition t o serving the function f o r which i t was selected, each ingredient must not i n t e r f e r e undesireably with the functions of other ingredients also present. PROCESSING In i t s common use, the term "vegetable food p r o t e i n " usually means a processed or derived o i l s e e d ingredient, l i k e defatted f l o u r and the higher protein content concentrate and i s o l a t e forms. Almost every defatted, dehulled o i l s e e d f l o u r contains over 50% protein (dry weight b a s i s ) . The terminology of soybean food proteins has essent i a l l y been adopted for other o i l s e e d s : "protein concentrate" t y p i c a l l y means a product containing over 70% protein (dry weight b a s i s ) , and a "protein i s o l a t e " contains over 90% p r o t e i n . For a i r - c l a s s i f i e d ingredients, "concentrate" refers t o f r a c t i o n s that contain more protein than the o r i g i n a l seed. Since f u l l - f a t or defatted f l o u r s , l i k e those of soy, can impart undesireable f l a v o r s , the more p u r i f i e d food proteins ingredients l i k e concentrates and i s o l a t e s are p r e f e r red f o r c e r t a i n a p p l i c a t i o n s . F u l l - f a t Products A flowsheet f o r preparation of glandless cottonseed f u l l - f a t kernels and subsequent processing of defatted f l o u r s and concentrates and i s o l a t e s i s shown i n Figure 1. This scheme, with s p e c i a l i z e d adaptations depending upon o i l s e e d species, i s t y p i c a l f o r processing of a l l oilseeds. F u l l - f a t g r i t s simply consist of whole and broken kernels that have been size-reduced by passing through c u t t i n g r o l l s or a hammer m i l l , and c l a s s i f i e d by s i e v i n g . Flakes are made by conditioning whole kernels or g r i t s with moisture and heat to a s s i s t t h e i r p l a s t i c i z a t i o n , and then passing through narrowly-set smooth r o l l s t o achieve the desired thickness. The advantage o f g r i t s and flakes i s that flowable ingredients can s t i l l be had, even from high o i l content seeds. T y p i c a l l y , f u l l - f a t f l o u r s are made by hammer m i l l i n g the seed to pass through 80-mesh or smaller s i z e screens. However, grinding of oilseeds containing over 25% o i l r e s u l t s i n s t i c k y f l o u r s . Thus, p a r t i a l l y - d e f a t t e d peanut and sunflower seed f l o u r s are made by f i r s t screw pressing the seed t o reduce the o i l t o 6-18% f a t content. I t i s common p r a c t i c e t o s t a b i l i z e f u l l - f a t products by preheating the seed, or by extrusion as i n the case of f u l l - f a t soybean f l o u r (6). Heat treatment deactivates l i p a s e s and lipoxygenases

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

34

PLANT PROTEINS

Ginned Glandle^ss Cottonseed

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Cleaning Conditioning of Fuzzy Seed Denuding - Separation Kernels

Hulls

Sizing Kernels

1

Middles

Fines

~

Roasting (Optional)

r

Conditioning Color Sorting (Optional) Accepted Kernels

Flaking Solvent Extraction

ι—

Rejected Kernels

Marc

Desolventizing

r Concentrate, Isolate Preparation Raw or Roasted Kernels

Animal Feed

Figure 1.

J Grinding Τ

Mlscella Solvent Recovery

Extracted Flakes

Defatted Flour

Crude Oil

General flow chart f o r production of glandless cottonseed food i n g r e d i e n t s .

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

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4. LUSAS AND RHEE

Vegetable Food Proteins in Traditional Foods

35

which catalyze development of free f a t t y acids and o f f f l a v o r s , r e s p e c t i v e l y , i n addition t o deactivating a n t i n u t r i t i o n a l factors such as t r y p s i n i n h i b i t o r s , hemagglutinins and other l e c t i n s . A l i m i t e d amount of enzyme-active f u l l - f a t soybean f l o u r i s sold f o r bleaching and conditioning of wheat f l o u r and bakery products (7). High o i l content seeds form pastes upon grinding, the best known example being peanut butter, which accounts f o r approximately 55% of domestic uses o f peanuts. By law, peanut butter consists of a minimum of 90% peanuts, with the remainder being e m u l s i f i e r s and/or hydrogenated f a t s t o prevent o i l i n g - o f f during storage, and s a l t , sweeteners and f l a v o r i n g s . I t i s t y p i c a l t o blanch (remove the pink/red s k i n or "testa") , roast, s p l i t , and remove the germ t o reduce b i t t e r f l a v o r from peanut kernels before grinding i n t o peanut butter. Defatted Flours Defatted f l o u r s are made by e x t r a c t i n g cleaned, dehulled o i l s e e d kernels i n o i l m i l l s that are sanitary i n design and operation f o r production of food-quality ingredients. When kernels contain less than 35% o i l ( l i k e soybeans and glandless cottonseed) , the seed may be conditioned, flaked and extracted d i r e c t l y with food grade commerc i a l hexane. Flakes of high o i l content kernels (peanuts and sunflower seed) w i l l not remain i n t a c t during solvent e x t r a c t i o n . I t i s t y p i c a l to prepress these seeds to an o i l content of approximately 16% and then solvent extract the broken or reflaked press cake. A f t e r countercurrent e x t r a c t i o n , the hexane i s drained and the meal desolventized and toasted by heat. The extent of toasting greatly a f f e c t s protein s o l u b i l i t y of the meal, and a range of soy f l o u r s with p r o t e i n d i s p e r s i b i l i t y indexes (PDI's) from 90 t o 20% i s a v a i l able. Defatted dehulled meals are converted into f l o u r s by ginding to pass though a 100 mesh screen. In producing sunflower f l o u r , 95% removal of h u l l s (grey and white striped) from confectionery v a r i e t i e s , and 97% removal of h u l l s from o i l - t y p e (black h u l l ) v a r i e t i e s i s necessary t o avoid noticeable grayness i n the f l o u r . Extraction also has the e f f e c t of concentrating the r e l a t i v e percentages of components remaining i n the meal. Upon e x t r a c t i o n , gossypol content i n glandless cottonseed f l o u r and chlorogenic acid content i n sunflower seed f l o u r can be increased by nearly 50 and 100%, respect i v e l y , from the o r i g i n a l contents i n kernels because these compounds are not soluble i n hexane and stay with the meal. Concentrates Concentrates are made by extracting water-soluble sugars and other compounds from defatted meals or f l o u r s . This i s t y p i c a l l y a secondary e x t r a c t i o n , using a c i d i c ethanol-water i n a chain-type or basket-type continuous extractor f o r processing f l a k e s , or a c i d i c water e x t r a c t i o n of f l o u r i n vats, followed by spray-drying (8). A c i d i c polar solvents are used at or near the i s o e l e c t r i c point of the p r o t e i n t o minimize i t s s o l u b i l i t y and l o s s . The reextracted flakes may then be ground i n t o a f l o u r . Concentrates are more bland than defatted f l o u r s , but s t i l l contain the f i b e r components of the kernel. A f t e r e x t r a c t i o n with a c i d i c ethanol or water, concentrates

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

PLANT PROTEINS

36

may be neutralized to pH 6-7 to improve t h e i r s o l u b i l i t y and functionality.

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Isolates Isolates t y p i c a l l y are made by s o l u b l i z i n g protein from defatted flakes with a l k a l i , removing the insoluble components by decanter or desludging centrifuge, p r e c i p i t a t i n g the protein at i t s i s o e l e c t r i c pH, concentrating the p r e c i p i t a t e by c e n t r i f u g a t i o n , and spray-drying the p r e c i p i t a t e f r a c t i o n . In some instances, pH of the acid p r e c i p i tate i s adjusted to near n e u t r a l i t y with sodium hydroxide to produce a "proteinate". Cottonseed protein i s unique i n having two f r a c t i o n s , "storage p r o t e i n " and "nonstorage p r o t e i n " , that can be r e a d i l y fractionated by p r e c i p i t a t i o n at selected pH's (9) Aqueous Extraction One of the e a r l i e s t methods of o i l extraction practiced by man was to mix f i n e l y ground dehulled seed i n hot water and skim o f f the layer of o i l which separated and rose to the surface of the vat. This process has been modernized by using mechanical grinders, s t a i n l e s s s t e e l extraction tanks, 3-phase centrifuges and spray dryers, and i s c a l l e d "aqueous extraction processing" (AEP). In t h i s procedure, the o i l i s removed as an emulsion which i s l a t e r broken by various means. The p r o t e i n remaining i n the l i q u i d may then be recovered and spray dried as protein concentrates or i s o l a t e s . To date, the following oilseeds have been extracted experimentally by AEP: soybeans (10) , glandless cottonseed (11), peanuts (12), sunflower seed (13), sesame (14), lupine (15), and coconuts U 6 ) . At the current state of the a r t , minimum achievable r e s i d u a l o i l contents i n AEP concentrates are: soybeans, 4-6%; glandless cottonseed, 6-8%; sunflower seed, 4-6%; peanuts 1-2%; and sesame 2-3%. However, the r e s i d u a l o i l s i n AEP f l o u r s , concentrates and i s o l a t e s are remarkably stable. I n d u s t r i a l Membrane Processing A v a r i e t y of processing options i s p o s s i b l e through i n d u s t r i a l membrane processing (IMP). U l t r a f i l t r a t i o n (UF) membranes of 20,000 molecular weight (MW) cutoff allow holding back of proteins (as retentate), while the sugars and water-soluble compounds pass through (as permeate). The permeate can then be processed by reverse osmosis (RO) to obtain e s s e n t i a l l y pure water as RO permeate, and the soluble compounds concentrated to about 20% s o l i d s as RO retentate. Experimental processes f o r producing soy concentrates and i s o l a t e s (17) , glandless cottonseed concentrates and i s o l a t e s (18), and peanut protein concentrates and i s o l a t e s (19) have been described. Various combinations of t r a d i t i o n a l IMP and AEP/IMP techniques also have been t r i e d i n preparation of vegetable protein concentrates and i s o l a t e s . COMPOSITION Protein contents of selected oilseeds and legume seeds, and food protein ingredients prepared by various procedures, are shown i n Table I. Amino acid contents and protein e f f i c i e n c y r a t i o s (PER's)

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986. 90

90

91

92

93

Protein Isolate

a

Protein Isolate

b

92

87 80°



Storage protein; Nonstorage protein; °Air-classified high-protein fraction.

71

68

Protein Concentrate

71



87

89

91

92

86

Protein Isolate

Membrane Process

71

68

67

70

68

Protein Concentrate

— —

52

77

70

71

71

72

Protein Concentrate

Aqueous Extraction Process

43

50

48

63

52

55

Defatted Flour

Classical Process

C



— —



53

43 C

29

30

26

24

43

30

43

Dehulled Seed (Kernel)

26

26

18

20

39

27

34

Whole Seed

Pinto Beans

Navy Beans

Sesame

Glandless Cottonseed

Peanuts

Soybeans

Fractions

Sunflower Seed

Table I. Percent Protein Content of Various Fractions of Several Oilseeds and Legumes

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PLANT PROTEINS

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38

of selected food protein ingredients are presented i n Table I I . Typical h u l l contents of seeds are: soybeans, 8-10%; peanuts (shells and t e s t a s ) , 20-30%; fuzzy cottonseed ( l i n t e r s and h u l l s ) , 40-50%; sunflower seed, 20-25%; sesame, 15-20%; and dry f i e l d beans, 8-10%. Typical o i l contents of dehulled kernels (and f u l l - f a t flours) are: soybeans, 20-23%; peanuts, 50-55%; glandless cottonseed 35-38%; sunflower, 50-55%; peeled sesame, 45-63%; and beans, 1-3%. Total carbohydrate contents of defatted f l o u r s are: soybeans, 26-30%; peanuts, 25-30%; glandless cottonseed, 23-27%; sunflower, 25-29%; sesame, 26-30%; and beans, 60-65%. Phytate contents of defatted f l o u r s are: soybeans 1.4-1.6%; peanuts, 1.7%; glandless cottonseed, 2.3-4.8%; sunflower, 1.5-1.9%; sesame, 3.6-5.2%; and beans, 1.4-1.8%. Trypsin i n h i b i t o r contents of dehulled kernels are: soybeans, 4-6%; peanuts, 0.8-1.5%; glandless cottonseed, 0.5-1.5%; sunflower, 0.71.8%; sesame, 0.5-0.8%; and beans, 2-3%. The U. S. Food and Drug Administration has set a l i m i t of 450 ppm free gossypol i n glandless cottonseed kernels and f l o u r , and the United Nations FAO/WHO has set l i m i t s of 600 ppm free gossypol and 1.2% t o t a l gossypol i n cottonseed products used f o r human feeding. FUNCTIONALITY Food protein ingredients are sometimes evaluated by comparative empirical t e s t s , including: nitrogen s o l u b i l i t y index (NSI) and protein d i s p e r s i b i l i t y index (PDI) p r o f i l e s over a range of pH's, water absorption, v i s c o s i t y , g e l l i n g strength, whipping and foaming c a p a b i l i t y (including volume and s t a b i l i t y of foam); f a t absorption, and o i l e m u l s i f i c a t i o n . Performance (including f l a v o r , texture and v i s u a l appeal) i s often evaluated p h y s i c a l l y using standardized food formulations, including bread (loaf volume, crumb and crust color and texture); sugar cookies (sheet spread, surface cracking), frankfurters (fat e m u l s i f i c a t i o n s t a b i l i t y , swelling and d r i p loss i n cooking, firmness and p e e l a b i l i t y ) ; meat loaves (moisture and f a t retent i o n during cooking); and frozen desserts (overrun and texture). However, the most meaningful evaluations are d i r e c t in-product trials. Proteins h i s t o r i c a l l y have been c l a s s i f i e d on the basis of t h e i r s o l u b i l i t y i n water (albumins); s a l t s o l u t i o n (globulins); alcohol (prolamines) and a l k a l i (glutelins) (20). Texture f u n c t i o n a l i t y of food proteins i s affected by many f a c t o r s , including r e l a t i v e proportions of the subfractions recovered by e x t r a c t i o n , and by s o l u b i l i t y as affected by heating or toasting. Also, i t should be remembered that most food products are complex systems with i n t r i n s i c pH and s a l t s o l u b i l i z a t i o n e f f e c t s , and that heat during product processing may coagulate and/or reduce s o l u b i l i t y of a l l proteins present, regardless of source. S o l u b i l i t y curves of proteins from s i x raw f l o u r sources are shown i n Figure 2. UTILIZATION F u l l - F a t Products Nut uses of roasted peanuts and sunflower kernels and deep f a t f r i e d soybean "nuts" are w e l l known. A s u b s t a n t i a l amount of vegetable protein i s consumed i n the

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986. 1.9 1.9 1.8 1.0 0.9

5.6 4.9 3.7 1.9 1.8

10.6 8.4 7.9 7.7 6.7

3.9 3.6 3.3 4.0 3.8

4.7 4.2 3.6 4.2 5.0

4.6 4.5 4.6 4.6 5.4

7.4 7.1 6.6 7.6 7.5

4.2 4.2 4.1 3.5 3.0 2.1 7.2 6.5

Sesame Defatted Flour Concentrate Isolate

Whole Navy Bean Flour

Whole Pinto Bean Flour

7.2 6.9 6.4

5.7 5.7 5.5

4.5 4.9 4.7 4.6 4.6 4.5 4.6 4.3

3.1 3.2 3.2 3.4 3.0 3.9 3.7 3.7

3.2 3.1 3.2 3.4 2.6

2.6 2.5 2.5

8.7 8.7 8.6

8.5 8.8 8.7 7.4 9.2

8.4 10.0 9.9

3.6 3.6 3.4

3.8 3.5 3.7 5.0 2.4

1.9 2.4 2.4

3.2 3.0 2.1

Sunflower Seed Defatted Flour Concentrate Isolate

6.0 6.2 6.1 6.4 5.6

3.2 4.3 3.6

8.9 9.1 9.1

4.0 4.0 4.0 6.2 2.9

5.3 4.5 4.4

4.3 4.2 3.7

Glandless Cottonseed Defatted Flour Concentrate Isolate, Classical Nonstorage Protein Storage Protein

6.4 6.7 6.6

5.1 4.8 4.9

3.0 3.0 3.0

5.4 4.9 4.8

Peanut Defatted Flour Concentrate Isolate

7.7 7.8 7.7

6.9 6.3 6.1

Soybean Defatted Flour Concentrate Isolate

1.1 1.0 1.0

1.5 1.5 1.5 1.6 1.0

1.0 1.1 1.0

1.3 1.5 1.4

1.0

3.5

6.0

4.0

4.0

5.0

7.0

5.5

FAO/WHO Reference Protein

Try

Met+Cys

Phe+Tyr

Thr

lieu

Val

Leu

Essential Amino Acid

Essential Amino Acid Profilée (g/16g N) and Protein Efficiency Ratios of Various Protein Food Ingredients

Lye

Table II.

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1.7 1.6 1.4

2.1 2.0 1.9

2.2 2.0 1.8 2.4 1.6

1.8 1.6 1.4

2.2 1.8 1.6



PER

PLANT PROTEINS

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40

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

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4.

LUSASANDRHEE

Vegetable Food Proteins in Traditional Foods

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form of whole seeds and f u l l - f a t products. Examples of whole seed uses include peanuts i n nut-form or i n confections, sunflower seed of the loose-shelled "confectionery" type (21); sesame seed used as bread and bun toppings and f o r breads and buns (22); roasted soybean nuts (7); and the more recently introduced glandless cottonseed kernels used i n confections, toppings f o r i c e cream novelties and salad bars, and i n s p e c i a l t y breads l i k e Proteina bread. The Food Protein Research and Development Center at Texas A&M University has developed a cookbook of glandless cottonseed kernel uses i n a v a r i e t y of appetizer, salad, main course, side d i s h , and dessert products (23). The only f u l l - f a t o i l s e e d f l o u r with s i g n i f i c a n t domestic sales i s soy. I t has been used i n bakery products, breakfast cereals, canned baby foods, canned i n f a n t formulas f o r l a c t o s e - i n t o l e r a n t babies, and adult dietary beverages Ç24). Bakery Products Baked goods are the oldest known compounded foods made by mankind. Each ingredient i s selected f o r one or more s p e c i f i c purposes based on contribution to f u n c t i o n a l i t y and c o m p a t i b i l i t y , and on r e l a t i v e cost. Bakery products formulators are receptive to new ideas, and vegetable proteins (primarily f l o u r s and concentrates) have been well-accepted when they show a cost advantage, f o r example, soy f l o u r s as replacements f o r dried nonfat milk s o l i d s and d r i e d eggs. Defatted f l o u r s are e s p e c i a l l y a t t r a c t i v e as protein sources , since 10-12% s u b s t i t u t i o n of wheat f l o u r with 50% protein f l o u r w i l l r a i s e t o t a l p r o t e i n content of t y p i c a l wheat breads by approximately 50%, and 25% s u b s t i t u t i o n w i l l almost double the protein content of cookies. Preparation of protein-enriched breads has been reported i n the l i t e r a t u r e using soy f l o u r s and p r o t e i n concentrates (25), peanut f l o u r s and peanut protein concentrates (2£, 27), glandless cottonseed f l o u r s , concentrates and i s o l a t e s (28) , sunflower seed f l o u r s and seed p r o t e i n concentrates (27) and sesame f l o u r s and p r o t e i n concent r a t e s (26) . Generally, vegetable food p r o t e i n ingredients are more absorbant than other dough components, with the r e s u l t that mixing time and l o a f volume i s decreased. In a d d i t i o n , pan bread crumb becomes coarser and occasionally darker i n color. Negative e f f e c t s on loaf volume appear to be inversely r e l a t e d to p h y t i c a c i d content. The maximum amounts of vegetable food p r o t e i n f l o u r s that can be substituted i n bread without a f f e c t i n g loaf volume and texture are 5-10% (depending upon the source) , and 18-20% can be substituted i n cookies without a f f e c t i n g spread and surface c h a r a c t e r i s t i c s (26). The quantity of vegetable p r o t e i n f l o u r that can be accommodated i n bread can be increased s u b s t a n t i a l l y by pre-toasting and by the use of approximately 1.5% sodium stearoyl 2 - l a c t y l a t e (28) and other emulsifiers. Breakfast Cereals Soy f l o u r s and concentrates are used i n compounded breakfast cereals, p r i m a r i l y f o r improving t o t a l p r o t e i n content and PER. In the absence of dry nonfat milk s o l i d s , glucose i s often included i n bakery products formulations to impart a toasted brown c o l o r . Most

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

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ready-to-eat breakfast cereals are e i t h e r extruded d i r e c t l y from doughs, or are f i r s t p e l l e t i z e d by extrusion, then flaked by r o l l s before toasting i n continuous ovens. Thus, i t i s r e l a t i v e l y simple to incorporate vegetable protein ingredients i n these products.

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Extruded Products Soy proteins are commonly extruded as intermediate forms f o r l a t e r use i n processed foods. Flours and concentrates are t e x t u r i z e d to resemble meat chunks and are sold under the names of Texturized Vegetable Protein (TVP), or texturized soy p r o t e i n (TSP). After rehydration with water (to approximately 18% p r o t e i n and 60-65% moisture content), up to 30% reconstituted soy protein can be used i n ground meat blends i n the school lunch program, and i n m i l i t a r y and other federal-sponsored feeding programs. These products are also used as meat enhancers i n standard of i d e n t i t y canned stews and c h i l i , and as meat extenders and replacers i n nonstandardized products such as p i z z a toppings and sauces, and i n "meatless" products l i k e taco f i l l i n g and "Sloppy Joes". Textured peanut (29), sunflower seed, and glandless cottonseed (30) f l o u r products have been prepared experimentally, demonstrating the v e r s a t i l i t y of extrusion t e x t u r i z a tion. Processed Meat Products The U. S. Department of Agriculture permits up to 3.5% soy f l o u r or soy concentrate i n standard of i d e n t i t y f r a n k f u r t e r s , up to 8% soy f l o u r i n scrapple and c h i l i con came, and up to 2% soy protein i s o l a t e (containing titanium dioxide-TiO as a tracer material) i n standard of i d e n t i t y frankfurters. Soy f l o u r s and concentrates can bind up to 3 times t h e i r weight of water, compared to nonfat dry milk s o l i d s which t y p i c a l l y bind only equal weights of water. A general p r a c t i c e i n evaluating new vegetable food protein sources i s to compare t h e i r performance to soy f l o u r i n frankfurters Ç31). An extruded soy protein i s o l a t e f i b e r product i s also used f o r s t r u c t u r ing mechanically deboned meats, p o u l t r y , f i s h and seafoods i n t o r o l l s , s t i c k s or f i l l e t s , or i n t o extruded shrimp shapes. USDA regulations also allow use of non-meat proteins i n products such as pumped ham and corned beef, provided the f i n i s h e d product contains a minimum protein content of 17%. Pumping to achieve a cooked y i e l d of 130% i s permitted (32). Dairy Products Cow's milk, extended with f u l l - f a t soy f l o u r , i s produced by CIATECH i n Chihuahua, Mexico, and a peanut isolate-extended water b u f f a l o milk ("Miltone") has been produced i n India f o r approximately 20 years Ç33). Establishment of soymilk plants i n Southeast A s i a and L a t i n America i s a growth industry and soy milks also are sold i n the United States. Various beverages, flavored to mask the taste of soybeans, have been introduced world-wide during the l a s t two decades. A major problem of vegetable proteins i s that, being globul i n s , they are r e a d i l y p r e c i p i t a t e d by calcium f o r t i f i c a t i o n , r e q u i r ed under domestic law f o r milk replacement products. Whereas consumers i n other countries r e a d i l y accept shaking of beverage containers

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

4. LUSAS AND RHEE

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before drinking, the domestic market prefers products which do not s e t t l e . Research progress has been made on succinylation and maleyl a t i o n o f soy, peanut and glandless cottonseed proteins t o prevent t h e i r p r e c i p i t a t i o n i n the presence of calcium f o r t i f i c a t i o n (34). Considerable i n t e r e s t has been shown i n uses o f vegetable food proteins i n cheese-type products. Attempts have been made to coprec i p i t a t e casein and vegetable protein i n the t y p i c a l vat process f o r making cheeses (_35). Rhee (36) has found that up t o 50% peanut protein i s o l a t e and 25% soybean i s o l a t e can be e f f e c t i v e l y s u b s t i tuted f o r sodium caseinate i n the preparation of i m i t a t i o n cheeses. Summary The invention o f new food forms i s not required to increase uses of vegetable food proteins i n the American d i e t . Uses o f f l o u r s , contrâtes and i s o l a t e s continue t o grow as increasingly more convenience foods are formulated and produced i n f a c t o r i e s , e i t h e r f o r grocery or i n s t i t u t i o n a l sales. REFERENCES 1. 2.

3. 4. 5. 6. 7. 8.

9.

10. 11. 12.

Bressani, R.; Elias, L. G.; Aguirre, Α.; Scrimshaw, N. S., J. Nutr. 1961, 74, 201-208. Orr, Ε., "The Use of Protein-rich Foods for the Relief of Malnutrition in Developing Countries: An Analysis of Experience"; Tropical Products Insti­ tute Monograph G 73, 1972; Aug. Aguilera, J. M.; Lusas, E. W., J. Am. Oil Chem. Soc. 1981, 58(3), 514-520. Carroll, Κ. K., J. Am. Oil Chem. Soc. 1981, 58(3), 416-419. Kritchevsky, D., J. Am. Oil Chem. Soc. 1979, 56(3), 135-140. Mustakas, G. C.; Albrecht, W. J.; Bookwalter, G. N.; McGee, J. E.; Kwolek, W. F.; Griffin, E. L., Jr. Food Technol. 1970, 24, 1290-1296. Circle, S. J.; Smith, Α. Κ., In "Soybeans: Chem­ istry and Technology"; Smith, A. K.; Circle, S. J., Eds; AVI Publ. Co., Westport, 1978. Campbell, M. F.; Kraut, C. W.; Yackel, W. C.; Yang, H. S. In "New Protein Foods"; Altschul, A. M.; Wilcke, H. L., Eds.; Academic Press, New York, 1985; Chap. IX. Martinez, W. H.; Hopkins, D. T. In "14th Nutri­ tional Quality of Foods and Feed. Part II. Ouality Factors: Plant Breeding, Composition, Processing, and Anti-Nutrients."; Friedman, M., Ed.; Marcel Dekker, New York, 1975; pp. 355-374. Rhee, K. C.; Cater, C. M.; Mattil, K. F. U. S. Patent 4 151 310, 1979. Cater, C. M.; Rhee, K. C.; Hagenmaier, R. D.; Mattil, K. F., J. Am. Oil Chem. Soc. 1974, 51(4), 137-141. Rhee, K. C.; Mattil, K. F.; Cater, C. Μ., Food Eng. 1973, 45(5), 82-86. In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.

P L A N T PROTEINS

44

13. 14. 15.

Downloaded by UNIV OF MICHIGAN ANN ARBOR on February 18, 2015 | http://pubs.acs.org Publication Date: June 18, 1986 | doi: 10.1021/bk-1986-0312.ch004

16.

17. 18. 19. 20. 21.

22. 23.

24. 25. 26. 27. 28. 29. 30. 31.

32.

33.

34. 35.

36.

Hagenmaier, R. D., J . Am. O i l Chem. Soc. 1974, 51(10), 470-471. Chen, S. L. M.S. Thesis, Texas A&M University, College Station, 1976. Aquilera, J . M.; Gerngross, M. F.; Lusas, E. W., J . Fd. Technol. 1983, 18, 327-333. Rhee, K. C.; Lusas, E. W. In "Tropical Foods: Chemistry and Nutrition"; Inglett, G. E.; Charalambous, G., Eds.; Academic Press, New York, 1979, Vol.2, pp. 463-484. Lawhon, J . T.; Lusas, E. W., Food Technol. 1984, 38(12), 97-106. Lawhon, J . T.; Manak, L. J . ; Lusas, E. W., J . Food S c i . 1980, 45, 197-203. Lawhon, J . T.; Manak, L. J . ; Rhee, K. C.; Lusas, E. W., J . Food S c i . 1981, 46, 391-398. Vickery, H. B., Physiol. Revs. 1945, 25, 347. Lusas, E. W. In "New Protein Foods"; A l t s c h u l , A. M.; Wilcke, H. L. Eds.; Academic Press, New York, 1985; Chap. XII. Johnson, L. Α.; Sulerman, T. M.; Lusas, E. W., J . Am. O i l Chem. Soc. 1979, 56(3), 463-468. Simmons, R. G.; Golightly, Ν. Η., "Cottonseed Cookery"; Food Protein R&D Center, Texas A&M University, College Station, 1981. Dubois, D. K.; Hoover, W. J . , J . Am. O i l Chem. Soc. 1981, 58(3), 343-346. Rooney, L. W.; Gustafson, C. B.; Clark, S. P.; Cater, C. M., J . Food S c i . 1972, 37, 14-18. Khan, M. N.; Rhee, K. C.; Rooney, L. W.; Cater, C. M., J . Food S c i . 1975, 40(2), 580-583. Khan, M. N.; Lawhon, J . T.; Rooney, L. W.; Cater, C. M., Cereal Chem. 1976, 53(3), 388-396. Khan, M. N.; Wan, P. J . ; Rooney, L. W.; Lusas, E. W., Cereal Foods World 1980, 25(7), 402-404. Aquilera, J . M.; Rossi, F.; Hiche, E.; Chichester, C. O., J . Food S c i . 1980, 45(2), 246-254. Taranto, M. V.; Meinke, W. W.; Cater, C. M.; M a t t i l , K. F., J . Food S c i . 1975, 40, 1264-1269. Smith, G. C.; Juhn, H. I.; Carpenter, Z. L.; M a t t i l , K. F.; Cater, C. M., J . Food S c i . 1973, 38, 849-855. "National School Lunch Program: Special Food Service Program f o r Children"; Federal Register 39(60), 1197. Chandrasekhara, M. R.; Ramanna, B. R.; Jagannath, K. S.; Ramanathan, P. R., Food Technol. 1971, 25, 596-598. Choi, K. R.; Lusas, E. W.; Rhee, K. C., J . Food S c i . 1982, 47, 1713-1716. Rhee, K. C.; Lusas, E. W., In "Annual Report"; Food Protein R&D Center, Texas A&M University, College Station, 1985. Rhee, K. C., In "Annual Report"; Food Protein R&D Center, Texas A&M University, College Station, 1985.

RECEIVED January 24, 1986

In Plant Proteins: Applications, Biological Effects, and Chemistry; Ory, R.; ACS Symposium Series; American Chemical Society: Washington, DC, 1986.