The effect of pressurized heat treatment on the textural, flavor, nutritional, and digestive characteristics of soft-boiled and marinated eggs

This paper investigated the changes in the texture, flavor, nutrition, and digestive characteristics of soft-boiled and marinated eggs (SME) during pressurized heat treatment (PHT) at 121 ℃ and 125 kPa for 15, 30, and 45 min. Eggs were pre-cooked in boiling water for 5 min, cooled and peeled in cool water, and then immersed in the brine at 65 ℃ for 2 h to prepare marinated eggs. The results showed that the hardness of SME (121 ℃, 0 min) was the lowest, with the egg white and yolk hardness were 1 368.05 and 530.43 g, respectively. After 15 min of PHT, the hardness of egg white and yolk increased significantly to 2 077.54 and 1 492.75 g (P < 0.05). The relaxation time of non-fluidizable water and free water of egg yolk decreased after PHT. The electronic nose test clearly distinguished the flavor difference before and after PHT, and moderate lipid oxidation was helpful to form new flavors. The protein digestibility of the SME yolk was significantly higher than the PHT groups. Vitamin A content of the SME (0.24 mg/100 g) was 1.26 times higher than the 30 min PHT group. After 30 min heat treatment, the vitamin E content of egg yolk decreased by 7.88%, phosphatidylcholine (PC) and phosphatidylethanolamine (PE) decreased significantly from 2.02 and 1.52 g/100 g to 1.73 and 0.92 g/100 g, respectively. Low temperature group (SME) maintained higher levels of fat-soluble vitamins and lecithin in the egg yolk than PHT groups.