Effect of pressure cooking on physicochemical properties of salted eggs

Pressure cooking is a curing and pretreatment method for food materials. Salt content, texture and oil exudation are important characteristics in determining the commercial value of salted egg. However, high salt content and little oil exudation of the product are typically observed after salting. In this study, the effects of pressure cooking at 100, 105, 110, 115, and 120 °C for various processing times on salted eggs were investigated. Salted eggs subjected to pressure cooking displayed an overall decrease in salt content, whereas oil exudation of the yolk increased: the treatment made the yolk less hard and gritty, while the albumen salte content decreased to 5%. Simultaneously, both unsaturated fatty acid and polyunsaturated fatty acid slightly decreased while saturated fatty acid content increased in the yolk during the treatment. According to scanning electron microscopy (SEM) results, some polyhedral granules were cracked in the salted yolk and a denser oil layer appeared after the treatment at 120 °C for 30 minutes as compared to other conditions. This paper provides an efficient and effective method to improve the quality of salted eggs.