Lactic acid fermentation improves rehydration and emulsifying properties of spray-dried egg yolk powder

In this study, we investigated the protein structures, powder characteristics, as well as rehydration and emulsifying properties of spray-dried egg yolk powder after short-time lactic acid fermentation (3.5 h). Results indicate that fermentation improved the rehydration and emulsifying properties of yolk powder. Limosilactobacillus reuteri-fermented yolk powder exhibited better wettability due to the porous structure of particles and higher hydrophilicity. Lacticaseibacillus rhamnosus-fermented yolk powder had an enhanced coefficient of stability due to its smaller particles and higher surface charge. The higher water solubility of fermented yolk powder samples is mainly attributed to their lower hydrophobicity and higher zeta potential. The enhanced emulsifying activity of fermented yolk powder samples is primarily related to their increased β-turn structure and better solubility. Furthermore, fermentation treatment altered powder moisture content and bulk densities, while not affecting its flow behavior and thermal stability. This study provides an effective approach to improving the quality of yolk powder.