Enhancement of foaming properties and storage stability of pasteurized liquid egg white through ultrasound modification

Abstract

Due to the high heat sensitivity of liquid egg white (LEW), there were a loss of foaming properties during pasteurization. At the same time, the temperature of pasteurization was limited by this property and did not limit the growth of microorganisms very well. Therefore, the article hoped to improve the foaming characteristics of pasteurized liquid egg white (PLEW) and to increase the stability during storage by using water-bath ultrasound. It was found that the foaming capacity of the pasteurization only group increased from 270% to 326% under optimal sonication conditions (60 Hz, 400 W, 15 min). The increase in protein solubility and decrease in particle size following ultrasound suggested that ultrasound had a deaggregation effect. The fact that surface tension was reduced suggested that sonication could provide more soluble proteins and a more flexible conformation for PLEW. Both free sulfhydryl and surface hydrophobicity were enhanced, which might be related to the disruption of protein molecular forces by the cavitation effect of ultrasound. The results of spectral analysis again revealed that the essence of ultrasound to improve the foaming properties of PLEW lied in changing the conformation of the protein molecule. Furthermore, the results also demonstrated that the ultrasound-treated LEW showed better foaming properties, minimal changes in viscosity, lower total volatile basic nitrogen content, and a longer shelf life (40 d) during storage. The quality of the ultrasound-treated group remained the most stable. Therefore, ultrasound has great potential for improving the foaming ability and stability of PLEW.