Papain heat treatment

Japanese Society of Miso Science and Technology Figure 18. Schematic representation of effect of heat treatment on soybean protein and its hydrolysis patterns by various enzymes. Pattern A, pepsin and other acid proteinoses pattern B, the proteinoses having an optimum near neutrality, such as papain, bacteria neutral proteinase, Aspergillus alkaline proteinase, Aspergillus neutral proteinase and pattern C, trypsin and in vivo nutritional... 

The digestion of heated or unheated soybean proteins by various enzymes is schematically compared with the nutritive values in Figure 18. Pattern A is typical of pepsin where, because of low pH of the reaction, the protein does not have to be denatured prior to addition to the reaction. Pattern B is typical of enzymes such as papain, bacterial neutral protease etc. where prior de-naturation of the substrate protein is required but there are no inhibitors of the enzyme present. Pattern C is typical of trypsin where prior heat treatment of the substrate protein is required to destroy inhibitors of trypsin as well as to denature the protein for digestion. The decrease in digestibility with prolonged heating in all three cases is due to modification of the substrate protein as described above. 

Improvement of protein solubility can be achieved through limited digestion of food proteins e.g. whey proteins, soy with various food-grade proteases (5 ). The complete solubilization of heat-denatured cheese whey protein (/sC -lactalbumin) by trypsin, within certain pH limits (pH 5-7), and partial solubilization by treatment with papain or neutral protease (54) has been reported. 

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