Effects of different lipids on the freeze-thaw stability and subsequent gelling properties of emulsified myofibrillar protein sols: perspective on interfacial behavior

The quality deterioration of Chinese-style fish paste products (e.g., fish-hua) during freeze-thaw (F-T) cycles is a critical issue in frozen food processing. We investigated the F-T stability of emulsified myofibrillar protein (MP) sols, a model of fish paste, focusing on the changes of interfacial films containing lipids with different unsaturation degrees and their effects on gel properties. Results showed that F-T cycles damaged interfacial proteins, causing ice crystal growth and droplet aggregation in sols and impairing gel texture and water-holding capacity (WHC). Soybean oil, rich in unsaturated fatty acids, enhanced interfacial MP adsorption during initial emulsification, maintained thicker viscoelastic films and smaller droplets during F-T, and yielded gels with higher springiness and WHC than those prepared with lard. Correlation analysis showed that lipid-regulated initial emulsification and interfacial adsorption were crucial for gel quality after frozen storage. These findings provide a basis for optimizing lipid composition to improve the F-T stability of emulsified fish-paste products. • Dynamic changes of the MP interfacial film during F-T cycles were revealed. • SOG formed thicker and more viscoelastic MP interfacial films than LG. • Adsorption-desorption behaviors critically shape interfacial protein film evolution. • The springiness and WHC of the SOG gels are better than the LG.