Changes in physicochemical properties and lipid oxidation lead to the formation of mud on salted egg yolks during storage. (30th May 2023)

• Record Type: Journal Article
• Authors: Xue, Hui; Liu, Huilan; Zhang, Guowen; Tu, Yonggang; Zhao, Yan
• Is Part Of: Food chemistry. Volume 409(2023)
• Publication Date: 2023-05-30
• Subjects: Product quality -- Lipid changes -- Oxidation products -- 1H NMR -- PLS-DA model; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2022.135341
• Languages: English
• ISSNs: 0308-8146

Abstract

Graphical abstract: Highlights: SEY would gradually oxidize and muddy during storage. After 3 weeks of storage, SEY began to muddy; after 9 weeks, SEY muddy seriously. SEY would produce many primary and secondary oxidation products during storage. DHA, EPA, ARA, and phospholipids may play a major role in the formation of SEY mud. SEY mud is mainly due to the enhanced fluidity and protein-lipid re-emulsification. Abstract: Salted egg yolk (SEY) becomes easily "muddy" during storage, leading to a decrease in the quality of salted eggs. The mechanism of SEY mudding was studied in this paper. The results showed that SEY hydrogen proton binding decreased, and SEY water and lipid fluidity increased during storage. In addition, the degree of lipid oxidation and monounsaturated fatty acids in salted egg yolk lipids (SEYL) increased, and primary oxidation products and secondary oxidation products were formed. Moreover, the structure of SEY was degraded to release lipids and proteins, and these proteins and lipids were re-emulsified to form new aggregates. Finally, by PLS-DA modeling analysis, it was found that the content of ω-3 polyunsaturated fatty acids and phospholipids changed significantly after SEY became muddy. These results suggest that the muddiness of SEY can primarily be attributed to higher fluidity and protein-lipid re-emulsification, and secondarily to the oxidation of SEYL.