Abstract: In order to confirm the regulation of endogenous antioxidant components in egg yolk on the oxidation process of eggs, fresh eggs were stored at 22 ℃ and 65% relative humidity for 50 days. The extent of egg yolk lipid oxidation, and the antioxidant capacity of lipophilic antioxidant component (LAC) and hydrophilic antioxidant component (HAC) were characterized during the storage period. The experimental results showed that egg yolk proteins were significantly degraded during storage, resulting in a decrease in the mean value of total sulfhydryl content by 29.69%, and an increase in the mean value of carbonyl content by 2.2 times. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed the degradation of phosvitin, high-density lipoprotein, and other proteins during egg storage, leading to a significant increase in conjugated diene (CD) value and malondialdehyde (MDA) content (P < 0.05). The free radical scavenging capacity of LAC was greater than that of HAC during egg storage. Compared with phospholipids in LAC, carotenoids in it had a relatively higher free radical scavenging capacity. Correlation analysis showed that the degree of egg yolk lipid oxidation was negatively correlated with the antioxidant capacity of phospholipids and carotenoids in egg yolk (P < 0.05), and the antioxidant capacity of phospholipids was positively correlated with that of carotenoids (P < 0.05). Compared with egg yolk proteins, LAC had a more significant regulatory effect on egg yolk lipid oxidation during egg storage, and there may be synergistic effects between the antioxidant components.

Key words: hen egg; storage; oxidation; antioxidant components