鸡蛋牛奶复合凝胶的质构属性和持水性能研究

Effects of different protein ratios and the main components (egg white and egg yolk) in egg on the textural and water holding properties of egg-milk composite gels were studied in this study. Analysis on physicochemical properties of egg-milk composite solutions showed that with an increase in the proportion of egg, protein surface hydrophobicity of the composite solutions increased, however, soluble protein content and solid content decreased, which was due to the lipoproteins in egg yolk. Analysis on rheological properties of composite solutions indicated that addition of egg could induce gels formation when the protein concentration of milk was low, at 5% and egg white was a key factor in this progress. The color of composite gels shifted to red and yellow, which was mainly caused by the natural pigment in the yolk component. And as the proportion of egg increased, the breaking depth of the composite gels showed a decrease trend, indicating that the gels springiness gradually decreased. The breaking strength of gels first increased and then decreased, and the maximum value was reached when egg content was 60%. Low-field nuclear magnetic resonance spectrum revealed that with the increase of egg content, the overall trend of free water content in the composite gels increased, indicating that water holding capacity decreased. The above results show that the ratio of egg and milk has an important effect on the performance of their composite gel. Among these, egg white plays a vital role on the gels-forming properties of composite solutions, and egg yolk has a stronger relationship with the properties of composite gels. The results could provide a theoretical guidance for design of egg-milk gel products with various taste properties.