Study on structure, properties and formation mechanism of cassava starch-faba bean protein heat-induced gel

In this experiment, the effects of different concentrations of cassava starch (CS) on the gel behavior of faba bean protein (FBP) were studied, focusing on the structural characteristics, gel characteristics and physical and chemical characteristics of the gel system. Specifically, with the increase of CS concentration from 4 % to 12 %, the morphology of the sample changed from fluid to gel solid. From the molecular structure, different concentrations of CS affected the secondary and tertiary structures of FBP protein, which made aromatic amino acids move to the surface of protein and promoted the transformation from α-helix to β-sheet. In addition, free sulfhydryl groups are converted into disulfide bonds, which increases the number of hydrogen bonds in the system. Microscopically, high temperature treatment leads to the cracking of CS and FBP structures, which enhances the noncovalent interactions between them, and forms a compact and smaller pore three-dimensional network structure, providing more channels for external moisture to transfer to the inside. From the gel characteristics, the water holding capacity, viscoelasticity and mechanical behavior of the composite gel were improved when the concentration of CS was 6 %-12 %. This work provides reference for the application of cassava starch-faba bean protein gel in specific food and medicine fields.