Soybean isolation

Divi R L, CHANG H c and DOERGE D R (1997) Anti-thyroid isoflavones from soybean isolation, characterization and mechanism of action. Biochem Pharmacol. 54 (10) 1087-96. 

Considerable interest has been shown in uses of vegetable food proteins in cheese-type products. Attempts have been made to coprecipitate casein and vegetable protein in the typical vat process for making cheeses (35). Rhee (36) has found that up to 50% peanut protein isolate and 25% soybean isolate can be effectively substituted for sodium caseinate in the preparation of imitation cheeses. 

The BMEA procedure was also used to produce high-purity bovine milk casein (Bazinet et al., 1999a) and soybean isolates (Bazinet et al., 1997 1999b) or to fractionate soybean 1 IS and 7S fractions (Bazinet et al., 2000b). 

The composition of improved canned meat with curative and prophylactic properties is given in this patent. It contains poultry meat (mechanically deboned), beef liver, semifat pig meat, powder of Jerusalem artichoke, soybean isolate, linseed oil, Caroline, vitamin E, and water at determined ratios. 

This system of preparing protein hydrolysates may be of general utility however, Roozen and Pilnik (12) treated a soybean isolate in an ultrafiltration reactor and experienced problems of a thickened retentate... 

Figure 6 Potential allergenic activity of different soy protein products. Potential allergenic activity of competitive soy proteins as percentage of maximal binding activity at the concentrations of competitive antigens of 102 /Ltg/mL. (1) Raw soybean, dehulled (2) heat-treated extrusion soy protein concentrate (3) soy protein isolate (4) proteolytic hydrolysate of soy protein isolate (5) EPM (1) product of soybean isolate without amino acid enrichment (6) EPM (2) product of soybean isolate with methionine enrichment (7) EPM (3) product of soybean isolate.

Gonzalez-Agramon, M.M., and Sema-Saldivar, S.O. 1988. Effect of defatted soybean meal and soybean isolate on the nutritional, physical, chemical, and organoleptic properties of wheat flour tortillas. J. Food Sci. 53 793-797. 

Seed-Meal Concentrates and Isolates. Seed-meal protein products include flours, concentrates, and isolates, particularly soy protein products. These can be used as extenders for meat, seafood, poultry, eggs, or cheese (see Soybeans and other oilseeds). Detailed information on soybean and other seed-meal production processes is available (13,14,18). 

Other experiments with Gibberellafujikuroi the fungus that produces gibbereUin, indicate that GA production is blocked by BAS 111. Very detailed and carehil experiments conducted with enzymes in ceU-free systems strongly support this mode of action, ie, using /-kaurene oxidase and cinnamate 4-mono-oxygenase isolated from pea apices and soybean suspension cells, and avanone-2-hydtoxylase and dibydroxypterocarpane 6-hydtoxylase from soybean suspension cells (31). 

An alternative method of produciag hydrocarbon fuels from biomass uses oils that are produced ia certaia plant seeds, such as rape seed, sunflowers, or oil palms, or from aquatic plants (see Soybeans and other oilseeds). Certain aquatic plants produce oils that can be extracted and upgraded to produce diesel fuel. The primary processiag requirement is to isolate the hydrocarbon portion of the carbon chain that closely matches diesel fuel and modify its combustion characteristics by chemical processiag. 

Fig. 7. Schematic outline for manufacture of soybean proteia isolates.

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). 

A wide number of proteia sources are available for use ia dairy substitutes. These iaclude animal proteias, ie, skim milk ia Hquid, coadeased, or dry form (filled products) caseia, caseiaates, and coprecipitates whey proteias oil-seed proteias, fish proteias and blood proteias. Oil-seed proteia sources iaclude soybean proteia coaceatrates and isolates, groundnut proteia, cottoaseed proteia, and sunflower seed, rapeseed, coconut, and sesame seed proteias (see Soybeans AND other oil seed). Other sources are leaf and single-cell proteias (see Foods, nonconventional). Of these proteia sources, milk and soybean proteias are most widely used. Proteia usage is based oa economics, flavor, fuactioaahty, and availabiUty. 

Soybean Protein Isolates. Soybean protein isolates, having a protein content of >90 wt%, are the only vegetable proteins that are widely used in imitation dairy products (1). Most isolates are derived from isoelectric precipitation, so that the soybean protein isolates have properties that are similar to those of casein. They are insoluble at thek isoelectric point, have a relatively high proportion of hydrophobic amino acid residues, and are calcium-sensitive. They differ from casein in that they are heat-denaturable and thus heat-labile. The proteins have relatively good nutritional properties and have been increasingly used as a principal source of protein. A main deterrent to use has been the beany flavor associated with the product. Use is expected to increase in part because of lower cost as compared to caseinates. There has been much research to develop improved soybean protein isolates. 

Soybean-based ice cream products, technologically feasible, are generally not in use because of flavor problems. An acceptable ice cream has been made by replacing 50% of the nonfat milk soHds with a dried soy protein isolate made up of cheese whey (21). Chocolate flavor has been widely used to mask the flavor of soybean proteins in ice cream (see Flavors and spices). 

The primary cell walls of most higher plant species contain XGs of the XXXG type, which bear trisaccharide side chains (8) on the backbone [247]. The seeds of many plants contain XXXG-type XGs, in which about 30% of the xylose units possess a /3-D-Galp residue attached to position 2. Several plant species produce XGs that lack fucose and galactose, and have a-L-Ara/ attached to 0-2 of some of the Xylp side-chains, such as XG isolated from olive fruit [262] and soybean (Glycine maxima) meal [263]. However, a-L-Ara/ residues occur also 2-linked directly to some of the Glcp residues of the backbone [154]. 

Fig. 2. Time course of accumulation of HSP mRNA. One jUg of poly(A) RNA isolated from soybean hypocotyls after different times of incubation at 42.5 °C (hs) or at additional times after transfer back to 28 °C after 4 h at the elevated temperature (recovery), were electrophoresed in formaldehyde agarose gels. Blots of these gels were hybridised with a mixture of four cDNAs encoding small soybean HSPs ranging from 15 to 23 kDa. From Schoffl Key (1982).

In order to produce soy protein, soybeans are first dehulled, flaked, and defatted to make white flakes . Soy protein concentrates are obtained by removing a portion of the carbohydrates from defatted and dehulled soybeans. Alcohol extraction is the method most commonly used to manufacture soy protein concentrates even though it results in the loss of isoflavones. Soy protein concentrates retain most of the fiber in the original soybean and must contain at least 65% protein on a moisture-free basis to meet quality standards. The most concentrated source of soy protein is soy protein isolates (or isolated soy protein, ISP), which is required to be at least 90% protein on a moisture-free basis. It is heat-treated during processing to insure inactivation of trypsin inhibitors. Most isolated soy protein is manufactured by water extraction from defatted and dehulled soybeans and it retains the natural isoflavones. 

Choung, M.-G. et al., Isolation and determination of anthocyanins in seed coats of black soybean (Glycine max (L.) Merr.), J. Agric. Food Chem., 49, 5848, 2001. 

Strack, D. et al., Cyanidin 3-oxalylglncoside in orchids, J. BioscL, 41, 707, 1986. Choung, M.-G. et al.. Isolation and determination of anthocyanins in seed coats of black soybean (Glycine max (L.) Merr.), J. Agric. Food Chem., 49, 5848, 2001. Covey, T., Analytical characteristics of the electrospray ionization process, in Biochemical and Biotechnological Applications of Electrospray Ionization Mass Spectrometry, ACS Symposium Series, Snyder, A.P. and Anaheim, C. A., Eds., Washington, D.C., 1995, chap. 2. 

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