Effects and mechanism of camellia saponin on the physicochemical and oxidative stability of camellia oil body-based emulsions

This study investigated the influence of camellia saponin (CS) on the physicochemical and lipid oxidative stability of camellia oil body-based emulsions (COBE) at pH 3.0 and 7.0 as well as proposed the underlying action mechanism. At pH 3.0, CS could not enhance the physicochemical stability of COBE with intensified aggregation and increased particle size because of the electrostatic neutralization effect of CS on oil body interfacial proteins (OBIP). By contrast, decreased particle size and improved long-term stability of COBE were observed at pH 7.0, which was due to the hydrophobic interaction between OBIP and CS molecules. Furthermore, COBE lipid oxidation was effectively retarded with CS incorporation, which was mainly attributable to the CS-OBIP interaction on the oil body surface, resulting in dramatic changes in OBIP conformation and structure (fluorescence quenching and increased α-helix structure) and the formation of composite interfaces.