Insolubilization of soybean protein

Irreversible Insolubilization of Soybean Protein During Drying. Soymilk is an economical high-protein food of high nutritive value produced by grinding soaked whole soybeans with water, heat-... 

Figure 7. Increase in the insolubilization of soybean protein during frozen storage at —5°C by the addition of small amounts of mercaptoethanol (ME), indicating the promotion of a sulfhydryl/disulfide interchange reaction by a disulfide bond splitting agent (lOj...

Figure 8. The insolubilization of soybean protein during storage at +5°C in a concentrated state and its solubility behavior in urea ana mercaptoethanol (ME)...

Reversible and Irreversible Insolubilization of Soybean Protein and Their Use for Foods... 

Figure 10. Schematic diagram of the insolubilization of soybean protein during...

Figure 12. Schematic diagram for the mechanisms of reversible and irreversible insolubilization of soybean protein (7)...

Deterioration of the physical properties of proteins during food processing or food storage can be ascribed primarily to an irreversible insolubilization of proteins. However, a deteriorative change for one purpose can be a favorable one for another purpose. In Japan, for instance, the irreversible insolubilization of soybean proteins has been utilized effectively for production of soybean protein foods, such as tofu, kori-tofu, and yuba. 

Efforts to manufacture phosphorylated proteins by modification of nonphosphorus proteins have been reviewed (229). Phosphorylation of proteins with phosphorus oxychloride causes cross-linking and insolubilization, but improves gel-forming and water-binding properties. Phosphorylation with sodium trimetaphosphate improves fimctional properties of soybean protein, including water solubility. Nutritional and toxicological investigations are needed before such modified natural proteins can be used in foods (230). 

Japanese Society of Food Science and Technology Figure 13. Comparison of rates of insolubilization during frozen storage between soybean protein solutions frozen immediately after preparation (heated and unheated) and frozen after 2 days of storage (heated and unheated). The heated samples were held at 100°C for 5 min prior to freezing ( ll). 

The reaction of starch phosphate with such proteins as soybean protein and casein was used to produce protective colloids for insolubilization of pigments in coatings and paper.1684 The complexation of starch phosphate with protein insolubilizes the latter, particularly when starch phosphate is in the form of an ammonium salt.1685... 

Soybean concentrate production involves the removal of soluble carbohydrates, peptides, phytates, ash, and substances contributing undesirable flavors from defatted flakes after solvent extraction of the oil. Typical concentrate production processes include moist heat treatment to insolubilize proteins, followed by aqueous extraction of soluble constituents aqueous alcohol extraction and dilute aqueous acid extraction at pH 4.5. 

Protein-Based Adhesives. Protein-based adhesives are normally used as structural adhesives they are all polyamino acids that are derived from blood, fish skin, casein [9000-71-9], soybeans, or animal hides, bones, and connective tissue (collagen). Setting or cross-linking methods typically used are insolubilization by means of hydrated lime and denaturation. Denaturation methods require energy7 which can come from heat, pressure, or radiation, as well as chemical denaturants such as carbon disulfide [75-15-0] or thiourea [62-56-6]. Complexing salts such as those based upon cobalt, copper, or chromium have also been used. Formaldehyde and formaldehyde donors such as hexametliylenetetraamine can be used to form cross-links. Removal of water from a protein will also often denature the material. 

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