Role of Medium-Chain Triglycerides on the Emulsifying Properties and Interfacial Adsorption Characteristics of Pork Myofibrillar Protein

Medium-chain triglycerides (MCTs) have been known to have multiple health benefits in treating metabolic disorders and reducing the incidence of obesity. In the present study, the partial replacement of lard with MCTs assisted by ultrasound treatment on the emulsifying stability and adsorption behavior of myofibrillar protein (MP) was investigated. The results revealed that ultrasound-assisted MCT emulsion had better emulsifying activity and emulsion stability than other groups. MCTs with ultrasound treatment considerably lowered the particle size, facilitated the formation of much smaller and more homogeneous emulsion droplets, and enhanced the oxidative stability of the emulsion. The emulsion had a pseudo-plastic behavior determined through static and dynamic rheological studies, and the MCT emulsion exhibited a larger viscosity and a greater storage modulus (G') compared with the lard emulsion. MCTs could promote protein adsorption levels at the O/W interface, forming a dense interfacial protein film. The surface hydrophobicity and reactive sulfhydryl content increased, accompanied by the transformation of α-helix and β-turn structure to β-sheet and random coil structure, indicating MCTs combined with ultrasound-induced unfolding and crosslinking of MP at the interface. The results suggested that MCTs may have the potential to enhance emulsifying properties in emulsion-type meat products.