Uncovering the dynamic changes in the proteins of camel milk powder during processing: Insights from structural properties and whey proteome.

This study investigated the variations in the structure, abundance, and biological functions in bioactive proteins during the processing of camel milk powder. Pasteurization, concentration, and spray-drying markedly affected the particle size, zeta potential, and secondary and tertiary structures of milk proteins. In particular, spray-drying increased protein particle size, disrupted ordered conformations, and promoted aggregation. Using 4D-DIA proteomics, 1392, 1298, 1179, and 1083 whey proteins were identified in raw, pasteurized, concentrated, and spray-dried milk, respectively. The proteins lost during processing were associated with lysosome, endocytosis, and key signaling pathways (PI3K-Akt, mTOR, and insulin), potentially weakening the hypoglycemic effect. Moreover, processing damaged high-abundance proteins (e.g., LPO, LF, XDH, CD14, C3, and SOX) and immunoglobulin superfamily and heat shock proteins, whose abundances decreased significantly, especially after pasteurization. Functional enrichment revealed that the reduced proteins impaired immune regulation, xanthine metabolism, enzyme activity, and ribosomal functions, directly diminishing the product's nutritional value. Collectively, these findings provide a scientific foundation for optimizing camel milk powder processing technologies.