Exploring the mechanism of emulsion stability in myofibrillar protein-κ-carrageenan emulsions prepared by different fat types: Perspective on interfacial adsorption kinetics and interfacial proteins conformation.

Abstract

This study investigated the mechanisms by which different fats influence myofibrillar protein (MP)-κ-carrageenan (KC) emulsion stability, focusing on interfacial adsorption kinetics and protein conformation. Flaxseed oil (FO), rich in unsaturated fatty acids, showed the highest emulsifying activity, stability, ζ-potential, and interfacial protein content, followed by Dongliao black pigs lard (DBPL) group, the Crossbred fattening pigs lard (CFPL) group, and the Hybrid fattening pigs lard (HFPL) group (P < 0.05). Compared to FO group, lard groups exhibited higher Turbiscan stability index and larger particle size, indicating poorer emulsion stability, confirmed by confocal laser scanning microscope. Interfacial kinetics revealed that MP rearrangement dominated interface film formation. FO achieved the highest interfacial pressure and rearrangement rate (P < 0.05), enhancing emulsion stability. Conversely, lard groups largely preserved the α-helix structure of interfacial MP, resulting in a compact, rigid molecular conformation. Consequently, the lard-formed interface film was inflexible and ineffective at resisting droplet aggregation.