Study on properties of TGase-induced pea protein–zein complex gels

Gel systems are widely used in the food industry. However, most plant proteins are usually not gelatinous enough for industrial producrion, so studies are needed to improve the properties of and develop new protein gels. In this study, different mass ratios of pea protein and zein (from 10:0 to 5:5) were combined to form nanoparticles using a pH-driven method, after which TG enzyme was used to induce the composite protein particles to form a gel. This study analyzed the effects of different mass ratios of different protein on enzyme-induced composite gel formation and the gel properties. The stability of the complexes protein solution was evaluated using multiple light scattering. Microrheological parameters such as the mean square displacement, elasticity index, and mesh size indicated that zein had a positive effect on gel properties. The gel strength (145.39 ± 1.34 g), water-holding capacity (93.21 ± 1.59%), and sustained release performance of the composite gel were the highest when the zein content was 20%. These effects was mainly attributed to the increase in the number of disulfide bonds and formation of new covalent bonds in the gel, which stabilized the gel structure. The structure of a complex protein and its functional properties can be regulated by controlling the protein mass ratio, providing a new approach for improving gel properties.