Impacts of heat and noncovalent bonding on interfacial property and structure of goat milk fat globule membrane proteins

This study explored how heat treatment (20-80 °C) and surfactants affect the structure and interfacial properties of goat milk fat globule membrane (MFGM) proteins. Heating to 80 °C increased protein particle size but reduced colloidal stability, inducing a molten globule-like state with altered secondary structure. Small-angle X-ray scattering (SAXS) revealed an increase in overall protein size and compressed colloidal calcium phosphate-casein clusters. Ionic surfactants (sodium dodecyl sulfate (SDS), dodecyl trimethylammonium bromide (DTAB)) dissociated aggregates and formed core-shell complexes, enhancing surface activity and thermal stability. The nonionic surfactant polysorbate 20 (PS20) adsorbed onto the MFGM surface with minimal structural disruption due to steric hindrance. Moderate heating and nonionic surfactants are promising for industrial MFGM protein applications. This study provides the first SAXS-based structural insights, recommending moderate heat and nonionic surfactants for optimal industrial MFGM proteins handling.