Species-specific physicochemical and digestive responses of goat and cow milk to moderate temperature-time heat treatments.

Limited knowledge of heat responses between goat and cow milk has constrained goat milk product development. This study compared goat and cow milk under moderate heat treatment (65 and 85 °C, 5-30 min) for changes in nutritional, physicochemical, digestive, and color attributes. Protein showed greater heat-induced changes than lactose and fat globules, with protein particle size in goat milk increasing from 184.9 ± 0.95 to 325.8 ± 3.69 nm, accompanied by more pronounced heat-induced aggregation and precipitation of β-Lg and α-La than in cow milk. Heat treatment increased protein digestibility by 15.6% in goat milk but decreased it by 9.0% in cow milk. Multivariate analysis identified milk source and temperature as the main drivers of these changes, with goat milk associated with colloidal destabilization and cow milk with color and rheological changes, whereas holding time had limited effects. These findings reveal distinct species-specific thermal response patterns and support milk-type-specific heat-treatment optimization for liquid milk products.