Abstract:

Microbial transglutaminase-induced (MTGase) gelation properties of protein isolates from red kidney bean, red bean, mung bean and soybean (designated as KPI, RPI, MPI and SPI) were investigated. SDS-PAGE analysis and dynamic oscillatory measurement indicated that the time needed to gelation onset (tgel) exhibited a following order, KPI＞MPI＞SPI＞RPI, whereas the order of G′ value after MTGase incubation was RPI＞MPI＞KPI＞SPI. Protein solubility analysis of MTGase-induced gels suggested that electrostatic interaction, hydrophobic interaction and hydrogen bonds except covalent bonds were the primary forces responsible for the formation of gels. In addition, disulfide bonds were also involved in gelation. Therefore, compared to SPI, the effects of protein isolates from Phaseolus on gelation stability were less obvious due to the devoid of disulfide bonds among individual subunits in protein isolates from Phaseolus.

Key words: Microbial transglutaminase-induced, Phaseolus, protein gel, rheological measurement