Effect of heat treatment on the nonlinear rheological properties of acid-induced soy protein isolate gels modified by high-pressure homogenization

Abstract

Soy protein isolate (SPI) is often used in food processing due to the high water holding capacity and high stability. This paper explored the effect of heat treatment (HT) on the nonlinear rheological properties of acid-Induced soy protein isolate gels modified by high-pressure homogenization. The effects of HT on the storage modulus G′, loss modulus G″ and gel rate of the SPI gel were studied through time sweep, frequency sweep and strain sweep tests. The effects of the Lissajous curve, Chebyshev stress decomposition and Fourier transformation were also investigated. The results illustrated that the HT significantly enhanced the mechanical properties of the SPI gel. The curve area and energy dissipation of the Lissajous curve after HT were significantly reduced. Chebyshev stress decomposition illustrated that HT enhanced the shear thickening behavior of SPI gel. The study also found that HT significantly improved the structure and strain resistance of the SPI gel structure. In short, HT significantly improved the nonlinear rheological properties of the SPI gel.