Sunflower defatted

Compositions of the four oilseeds are given in Table 2. All except soybeans have a high content of seed coat or hull. Because of the high hull content, the cmde fiber content of the other oilseeds is also high. Confectionery varieties of sunflower seed may contain up to 28% cmde fiber on a dry basis (8). Soybeans differ from the other oilseeds in their high protein and low oil content. AH these oilseeds, however, yield high protein meals when dehuUed and defatted. 

Minor Constituents. All four oilseeds contain minor constituents that affect the use of the defatted seeds, especially in feeds and foods. Percentages of phytic acid [83-86-3] (3), for example, are soybean, 1.0—1.5 (30) cottonseed kernels, 2.2—3.8 (25) peanut kernels, 0.8 (25) and sunflower, 1.6-1.7 (31). 

Soybeans contain only 1—25 ppm of phenofic acids (33) whereas defatted sunflower meal contains 2.7% chlorogenic acid, 0.38% quinic acid, and 0.2% caffeic acid (34). Chlorogenic acid turns from yellow to green and finally to brown as the pH is raised from 7 to 11. Interaction of chlorogenic acid... 

Use of some oilseed proteins in foods is limited by flavor, color, and flatus effects. Raw soybeans, for example, taste grassy, beany, and bitter. Even after processing, residues of these flavors may limit the amounts of soybean proteins that can be added to a given food (87). The use of cottonseed and sunflower seed flours is restricted by the color imparted by gossypol and phenoHc acids, respectively. Flatus production by defatted soy flours has been attributed to raffinose and stachyose, which are removed by processing the flours into concentrates and isolates (88). 

Typically, full-fat flours are made by hammer milling the seed to pass through 80-mesh or smaller size screens. However, grinding of oilseeds containing over 25% oil results in sticky flours. Thus, partially-defatted peanut and sunflower seed flours are made by first screw pressing the seed to reduce the oil to 6-18% fat content. 

Defatted flours are especially attractive as protein sources, since 10-12% substitution of wheat flour with 50% protein flour will raise total protein content of typical wheat breads by approximately 50%, and 25% substitution will almost double the protein content of cookies. Preparation of protein-enriched breads has been reported in the literature using soy flours and protein concentrates (25), peanut flours and peanut protein concentrates C26, 27), glandless cottonseed flours, concentrates and isolates (28), sunflower seed flours and seed protein concentrates (27) and sesame flours and protein concentrates (26). 

Sunflower Seed. Emulsion capacity of defatted sunflower meal was investigated by Huffman et al. (45) at three pH levels (5.2, 7.0, 10.8), blender speeds (4500, 6500, 9000 rpm), and oil addition rates (30, 45, 60 ml/min). With low mixing speeds and rapid rates of oil addition, optimum emulsion capacity occurred at pH 7.0. These authors related the observed emulsification properties to protein solubility, surface area and size of oil droplets, and rate of protein film formation. 

Lin et al. ( 6) measured the emulsion capacity of defatted sunflower seed products. Data in Table VII show that sunflower flour was superior in emulsifying capacity to all other products tested. The emulsions were in the form of fine foams and were stable during subsequent heat treatments. The diffusion-extraction processes employed to remove phenolic compounds dramatically reduced emulsion capacity, although isolating the protein improved emulsion capacity to some extent. 

Table VII. Emulsion capacity of defatted sunflower seed products.

Defatted Sunflower Seed Product % Protein % Oil Emulsified... 

Lin et al. (15) showed that sunflower meal was superior to soybean and sunflower concentrates or isolates In emulsion capacity. McWatters and Cherry (9) compared select functional properties of defatted soybean, peanut, field pea, and pecan flours and showed that major seed storage proteins were important in emulsifying and foaming properties. Protein solubility was related to the quality of the emulsions and foams. Behavioral characteristics contributed by nonprotein components that occur naturally In the seeds, especially carbohydrates, were Implicated. 

Sunflower meal (blended with wheat flour) can be used for human nutrition. Despite their dark color, sunflower protein concentrates are of excellent digestibility. A method was proposed (147) for obtaining sunflower protein concentrates from defatted wholemeal sunflower flour, through extraction of these proteins with a basic solution. The process yields a concentrate of 71% protein (dry basis), rich in glutamic and aspartic acids. The supernatant liquid, rich in potassium and phosphorous, can be used as agricultural fertilizer. 

Defatted oil seed meals are known to contain large amounts of nutritional proteins which can be recovered for use in food and pharmaceutical industries. Protein recovery from solution is often achieved through precipitation followed by solids-liquid separation. For efficient recovery, it is imperative to maximize the solids yield and the mean particle size, and minimize the spread of particle size distribution (PSD). In this research program, recovery of canola and sunflower protein precipitates has been investigated. Three different types of precipitators (batch, MSMPR, and tubular) and four different precipitants (HCl, carboxymethylcellulose (CMC), sodium... 

Figure 1. Extraction and precipitation yields of canola and sunflower proteins at different pH (extraction from industrially defatted meals).

Table I. Amino Acids Composition of Defatted Canola (Rapeseed) and Sunflower Meals (19)...

Amino Acid Content in defatted meal (g/16gN) Canola Sunflower Requirem entsof human adults ... 

Experiments were performed to determine the optimum pH for the extraction of proteins from the industrially defatted canola meal (Federated Co-op Ltd., Saskatoon, SK) and sunflower meal (Cargill Inc., West Fargo, ND), and the minimum solubility pH (isoelectric pH) for precipitation. Details of the experimental methods can be found in (7) and (13) respectively. The extracted protein solutions were then used to recover proteins by precipitation. Four different types of precipitants aqueous HCl, HMP, CMC, and ammonium sulphate, were used for studies on the yields of canola protein. Further studies on isoelectric precipitation (using aqueous HCl as a precipitant) were carried out in three types of precipitators (Batch, MSMPR, and tubular) to study kinetic parameters and effects of precipitator type and operating conditions on PSD. The first two types of precipitators were used for canola protein and all three types were used for sunflower protein. Details of these experimental setups can be found in (7) for canola protein and (13,11) for sunflower protein. 

When nuts are harvested, dehulled, shelled and defatted, the residue is excellent as a feed for domestic animals. The protein, carbohydrates, fiber, minerals, most of the vitamins, and some of the fat remain in the residual cake or powder. The meal of coconuts, sunflowers, peanuts, and other nuts and seed is ground and/or pelletized as concentrates in feed for many animals. The residue from the respective nuts or seed is formulated into balanced rations for dairy cattle, beef cattle, racing horses, draft horses, pigs, sheep, poultry, turkeys, wild birds, fancy birds, catfish, goldfish and other domestic animals. 

The flours highest in protein are those made from defatted fish and from the defatted oilseed meals (cottonseed, peanut, soybean, and sunflower). It is noteworthy that these flours are currently being used around the world as protein supplements. 

Composition of sunflower meai (sun meai)—The composition of defatted sunflower meal varies considerably, depending primarily on the method of processing. A typical commercial sunflower meal contains approximately 9.0% water, 45% protein, 3.5% fat, 9.5% fiber, 7.0% ash (mineral), and 25% carbohydrate. 

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