Protein Hydrolysate

The generic term for protein substances that have been modified to make them more soluble in water. This includes acid hydrolysis that is used to develop hydrolyzed vegetable proteins (HVP) and enzyme hydrolysis through the use of proteases. Proteolytic enzyme hydrolysis is accomplished by the incubation of the substrate protein at the proper enzyme activity conditions. These conditions include the proper range of temperature and moisture. When the enzyme process has come to completion, a deactivation of the enzyme usually is necessary. The process of enzyme hydrolysis would include a number of steps. First, the pH is adjusted by the use of buffering salts, etc. Secondly, the proper amount of enzyme, substrate, and mixing is made. Then a proper elevation of temperature is maintained (incubation). Finally, after the enzyme has done its job, one approach to stop the continual action of the enzymes might be to raise the temperature to kill the enzymes. Another way to kill the reaction might be to add enzyme inhibitors. Enzymes can be immobilized, that is, attached to inert carriers. This way, the enzymes might be removed by filtration, etc. Enzymatic derivation of flavor materials is considered to be a natural process (CFR Title 21 101.22-Definition of a Natural Flavor). Yeast autolysis occurs with endogenous enzymes and is therefore also considered a natural process. When Kehldahl Nitrogen Assay is used to determine the protein content, the common practice is to use a factor of 6.25 for soy protein and 5.7 for wheat gluten. See Hydrolysis, Autolysis.

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