Abstract
Heat denaturation of insoluble collagen in animal foods may have important roll in processing and cooking. The transformation of pig skin collagen to gelatin and some degradation products caused by heating in water under varying conditions of time, temperature, pH and salt concentration were examined. Amounts of collagen solubilized during heating increased with the increasing of time and temperature and reached to the limit value depending upon the temperature.This limit shifts to a greatly higher value when heating pH was reduced lower than 4. Salt existed in the heating medium depressed the solubilization of collagen at acidic pH and accelerated it in neutral range. When the solubilizates by heating were examined by means of disc electrophoresis and Sepharose 4B column chromatography, components corresponding to α, β and γ chains of collagen were noticed in them. However, the amounts of degradation products of molecular sizes smaller than α chain increased with the progress of gelatinization. This indicates that a part of peptide bonds of original collagen molecule was broken during heating in water.
