Effects of short-term fermentation with lactic acid bacteria on egg white: Characterization, rheological and foaming activities

Lactic acid fermentation is a green technology to modify functionalities of food ingredients, including proteins. In this study, the commercial lactic acid bacteria (Streptococcus thermophiles and Lactobacillus bulgaricus) were used to ferment egg white for 0 h, 3 h, 6 h, and 9 h, respectively. The microbial composition significantly changed during the process, and the abundance of B. Lactobacillus peaked at 6 h. The free sulfhydryl groups of egg white proteins (EWP) gradually decreased, and the surface hydrophobicity increased from 28.7 to 52.0 after 6 h. The rheological experiments illustrated that fermented samples exhibited a lower apparent viscosity, and the sample at 6 h possessed the highest storage modulus (G'). Correspondingly, the foaming ability of egg white significantly improved from 72.3% to 93.0% after 6 h of fermentation. This study suggested that moderate lactic acid fermentation endowed egg white with stronger foaming activities, and thus had a potential to be applied in improving texture quality of egg products.