Effects of heat treatment on camel milk physicochemical properties, microstructure and protein profiling

Camel milk exhibits unique nutritional and functional properties, yet its proteins show distinct thermal stability compared with those of bovine milk. Understanding their response to heat is critical for ensuring both quality and safety during processing. In this study, the effects of heat treatment at 75, 85, 95, 105, and 120 °C for 15 s on the physicochemical and structural characteristics of camel milk proteins were evaluated. Moreover, the proteomic profile of whey protein of camel milk was analyzed using 4D proteomics. The results showed that as the temperature increases, larger protein aggregates of camel's milk observed in particle size, zeta-potential value, turbidity and confocal laser scanning microscopy images. High-temperature accelerated protein denaturation and unfolding, accompanied by a marked increase in free sulfhydryl groups and surface hydrophobicity. SDS-PAGE analysis that the bands representing lactoferrin, α-casein, and β-casein were markedly weaker after heat treatment. Proteomic analysis further demonstrated a temperature-dependent decline in whey protein abundance, with differentially abundant proteins primarily related to protein binding and immune system regulation. These findings provide fundamental insights into the heat-induced changes of camel milk proteins and offer a theoretical basis for optimizing thermal processing conditions to maintain its nutritional and functional quality. • Heating above 105 °C caused larger aggregates via hydrophobic interactions and reduced β-casein stability. • α-helices/β-turns decrease, β-sheets/random coils increase accordingly, directly confirming heat denaturation. • Excessive heat treatment downregulates key bioactive proteins (e.g., lactoperoxidase, immunoglobulins), reducing camel milk’s nutritional and functional properties.