Preparation and Characterization of Zein-Based Oil-in-Glycerol Emulsion Gel

In this study, anhydrous zein-based oil-in-glycerol emulsion gels were prepared by a medium temperature induction method. The impact of zein and corn oil contents on the formation and structure of emulsion gels was explored. It was found that increasing the content of zein (4%-8%) enhanced the continuous phase network structure and therefore significantly improved the gel strength, increasing the gel hardness from (3.43 ± 0.14) to (8.15 ± 0.13) N, the oil-holding capacity from (97.64 ± 0.21)% to 100%, and the solvent-holding capacity from (84.15 ± 0.38)% to (96.34 ± 1.20)%. The increase in corn oil content (50%-70%) did not significantly change the gel strength, but enhanced the gel viscosity and thixotropic recovery performance. Meanwhile, the gel stability was improved by the tight arrangement of oil droplets, and the gel oil-holding capacity and solvent-holding capacity were maintained at high levels, (95.51 ± 0.56)%-(99.17 ± 0.85)% and (83.29 ± 2.23)%-(93.39 ± 1.01)%, respectively. All formulations formed stable emulsion gels with good temperature response behavior. Our results proved that the gel properties could be regulated by adjusting the contents of zein and corn oil. This study provides a theoretical basis for the practical application of zein-based emulsion gels in foods, improving the comprehensive utilization rate of zein.