Effect of the double heating cycle on the thermal gelling properties of vicilin fractions from soy, mung bean, red bean and their mixture with soy glycinin

Abstract

This study investigated the effect of a double heating cycle (90 °C) on the thermal gelling behavior of fractionated vicilins from soybean (SV), mung bean (MV) and red bean (RV) with and without soy glycinin (SG). Both MV and RV consisted of peptides with relatively low Mw comparing to those of SV. Differential scanning calorimetry (DSC) indicated that MV and RV had a greater thermal stability than those of SV. Based on oscillatory shear rheometry, the first heating could not cause the gelation of MV and RV, but the thermal gel of both vicilins could be formed by the second heating stage. The stiffness of the RV gel was lower than that of MV. Based on texture profile analysis (TPA), the hardness and springiness of gel prepared by MV did not differ from those of SV, whereas RV gel showed high cohesiveness but low hardness and springiness compared to that of SV (p < 0.05). The gumminess of MV and RV gels was lower than that of SV gel (p < 0.05). The differences in TPA parameters between MV and RV were mainly due to different contributions of hydrophobic and electrostatic interactions, which also affected their microstructures. However, their gel characteristics disappeared when SG was mixed with these vicilins. The results indicated that both MV and RV had a potential to regulate the textural properties of soy protein-based gel matrix, and double heating was necessary to form a viscoelastic thermal gel containing vicilin fractions.