Insolubilization soybean protein products

Reversibly insolubilized soybean protein products possess various functional properties, such as binding, emulsification effect, etc. These functionalities may appear when the native protein molecules are unfolded during heating in food processing. Therefore these products, such as soybean protein isolate, are useful as binders or emulsifiers for sausage, hams, etc. 

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. 

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. 

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