Yang_2026_Food.Chem_525_150359

Sodium alginate (SA) has weak interfacial adsorption and poor intrinsic antioxidant capacity, which can promote droplet coalescence, oxidative deterioration, and shortened shelf life during emulsion storage. Gallic acid (GA) was grafted onto SA via lipase catalysis to construct a dual-mechanism stabilizer. Structural analyses confirmed covalent grafting (degree 31.4%) and introduction of aromatic hydrophobic groups and phenolic hydroxyls. GA-SA improved emulsion stability through coupled physical and chemical mechanisms. Physically, GA-SA formed stronger interfacial films; despite slightly larger initial droplets, droplet size increased only 41% over 14 days versus 253% for SA, and GA-SA remained uniform for 15 days, whereas SA destabilized after 11 days. Chemically, GA-SA reduced the accumulation of peroxide value (POV) and thiobarbituric acid reactive substances (TBARS) by 60-70% under ambient and accelerated oxidation conditions and inhibited Staphylococcus aureus and Escherichia coli. This strategy provides a natural multifunctional stabilizer for extended emulsion shelf life.