Insolubilization irreversible

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-... 

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

IRREVERSIBLE INSOLUBILIZATION (UNFOLDED MOLECULES) (a) SOLUBLE STATE (c) FROZEN STATE... 

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

Irreversible insolubilization of proteins may occur mainly through formation of both intermolecular disulfide and hydrophobic bonds. The product can be quite different depending on the relative contribution of these two types of bonds. The hydrophobic bonds are formed among the hydrophobic amino acid side chains contributed by valine, leucine, isoleucine, phenylalanine, etc. 

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. 

The Choice of a Matrix Resin. As was mentioned earlier, the common matrix resins for today s lithography are phenolic resins such as Novolac and poly(4-hydroxystyrene). Though some of our early work had involved simple water soluble alcohols such as poly(vinyl alcohol), schemes for their reversible in situ insolubilization were sometimes complicated by irreversible processes or side-reactions. As a result we chose to test the water-soluble linear polymer that is obtained by free-radical polymerization of 2-isopropenyl-2-oxazoline, 1. Monomer 1 can be polymerized through a variety of techniques, as shown in Scheme 1 (6,7). Both radical or anionic polymerization conditions lead to a polymer containing pendant oxazoline rings, while a more complex structure is obtained under cationic conditions as both the vinyl and the oxazoline moieties are reactive. 

The d.s. of macroporous cellulose /m/i5-2,3-carbonate obtained when cellulose reacts with ethyl chloroformate can be controlled by the addition of small quantities of water,225 This procedure produced a matrix that is suitable for the covalent binding of chymotrypsin the insolubilized enzyme is appreciably active towards high-molecular-weight substrates. The amount of chymotrypsin covalently bound to macroporous cellulose /mn5-2,3-carbonate and the caseinolytic activity of the immobilized enzyme are substantially improved by swelling the matrix in DMSO before the enzyme is coupled.22 The porosity of the insoluble support is increased by swelling, so that macromolecules can diffuse into it. The physical properties of cellulose /ra 5-2,3-carbonate are irreversibly destroyed unless it is properly stored. 

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