Effect of sodium trimetaphosphate modification on the structure and rheological properties of zein

Abstract

The modification of zein with sodium trimetaphosphate (STMP) as a cross-linking agent was studied. The effects of the mass ratio of STMP to zein (R S/Z ), pH, reaction temperature and time on the rheological properties of modified zein solution (Z-SP) were evaluated. By using response surface methodology, the optimal modification conditions were also determined as following: R S/Z 0.03, pH 6.8, reaction time 2 h, reaction temperature 25 °C. Under these conditions, the observed shear stress of Z-SP solution was 35.0025 Pa, close to the predicted value. Compared with natural zein, the viscosity of Z-SP increased with the increasing shear rate, which was attributed to the structural changes, as evidenced by circular dichroism (CD) and Fourier transform infrared (FT-IR) analysis.

Structural modification of zein-based oil-in-glycerol emulsion gels for improved textural and digestion behaviors

“…Zein is the main storage protein in corn and accounts for about 45-50% of the total corn protein. 1,2 It is the main byproduct of corn processing for ethanol, starch and oil. Due to the poor water solubility, zein has limited applications in the food industry and is mostly used as feedstuff.…”