The gel was prepared by thermal induction of egg yolk powder as raw material in this study. Firstly, the lipid component of egg yolk powder gel and the correlation between the gel strength of egg yolk powder and Texture Profile Analysis were analyzed, and then the changes of oxidation products. The method of principal component analysis (PCA) was used to determine the relationship between secondary oxidation products and fatty acids content. Moreover, Redundancy analysis (RDA) was used to study the relationship between fatty acids, Phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), peroxide value (POV) in Egg Yolk Gel. Result indicated, Lipid content of egg yolk powder gel was lower than egg yolk powder, the gel strength was positively correlated with hardness, adhesion, viscosity and masticatory ( p < 0.01), and had a significant negative correlation with recovery ( p < 0.01). In the nuclear magnetic map, the signal of primary oxidation product E, E-conjugate form was at 5.70 ppm, the signal of secondary oxidation product n-aldehyde was at 9.75 ppm. Combined with PCA and RDA, the results showed that the changes of fatty acid content were negatively correlated with the changes of peroxide value, while the changes of PC and PE were positively correlated, and the contents of fatty acids, PE, PI and PC were negatively correlated with the changes of POV, of which PE and POV were the most correlated.
Jie Jia,Xixi Zhang,Xin Jia,Jiayi Duan,Ziyan Wu,Xiaofan Deng,Junlin Ge
In this study, we investigated the protein structures, powder characteristics, as well as rehydration and emulsifying properties of spray-dried egg yolk powder after short-time lactic acid fermentation (3.5 h). Results indicate that fermentation improved the rehydration and emulsifying properties of yolk powder. Limosilactobacillus reuteri -fermented yolk powder exhibited better wettability due to the porous structure of particles and higher hydrophilicity. Lacticaseibacillus rhamnosus -fermented yolk powder had an enhanced coefficient of stability due to its smaller particles and higher surface charge. The higher water solubility of fermented yolk powder samples is mainly attributed to their lower hydrophobicity and higher zeta potential. The enhanced emulsifying activity of fermented yolk powder samples is primarily related to their increased β-turn structure and better solubility. Furthermore, fermentation treatment altered powder moisture content and bulk densities, while not affecting its flow behavior and thermal stability. This study provides an effective approach to improving the quality of yolk powder.