Abstract: Interaction between konjac glucomannan (KGM) and soybean protein isolate (SPI) has been studied by means of dynamic viscoelastic measurements. The factors such as gelling time, temperature, frequency and strain were revealed in this study. The storage modulus G′was larger than the loss modulus G″for the gel mixtures of KGM and SPI at high concentration. It showed that the association of molecular chains and sol-gel transition was occurred and a three dimensional network was formed between KGM and SPI. An alkaline coagulant treatment for mixtures of KGM and SPI improved the viscoelastic properties of the gel. The frequency dependence of G′and G″for mixtures of KGM and SPI without alkaline at lower frequencies range from 10-2 to 101 rad/s were observed, but at higher frequencies the frequency dependence of G′and G″for mixtures of KGM and SPI with or without alkaline were not confirmed in this study.

Key words: Konjac glucomannan, soybean protein isolate, dynamic viscoelastic, gelation