Comparative analysis of freeze-drying and spray-drying on the physicochemical modulation and symbiotic functionality of egg white for Bifidobacterium animalis.

This study investigates the physicochemical modulation of egg white (EW) via targeted drying to develop dual-action protectants and prebiotics for Bifidobacterium animalis. Using yeast desugarization, freeze-drying (FDEW), and spray-drying (SDEW), we elucidated significant process-induced transformations. FTIR-PCA mapped distinct protein conformational shifts, highlighting heat-induced aggregation and the generation of Maillard reaction products (MRPs) during spray-drying. These chemical modifications strategically altered EW functionality. Desugared FDEW demonstrated superior cryoprotective efficacy, maintaining 63-94% B. animalis viability during lyophilization by mitigating detrimental MRP formation and osmotic stress, outperforming skim milk control. Conversely, heat-induced protein aggregation and MRP synthesis in SDEW prevented the complete mortality of probiotics under severe thermal stress. Furthermore, these thermally modified SDEW matrices exhibited remarkable prebiotic potential, significantly enhancing B. animalis growth kinetics beyond commercial inulin. Ultimately, modulating processing conditions systematically alter EW's structural composition, transforming a ubiquitous ingredient into a highly functional symbiotic delivery system.