Investigating the effect of catechin on the emulsification and oxidation stability of myofibrillar protein-diacylglycerol emulsions

The effects of catechin on the emulsification and oxidation stability of myofibrillar protein-diacylglycerol (MPDAG) emulsions were investigated. Lard samples, namely, lard, unpurified glycerolytic lard (UGL), and purified glycerolytic lard (PGL), were used as oil phases. The emulsifying effects of UGL- and PGL-based emulsions were superior to those of lard-based emulsions (P < 0.05). The emulsifying properties of MP-DAG emulsions increased initially and then decreased with a rise in the catechin concentration, with 20-mu mol/g catechin exhibiting optimal emulsification activity and stability (P < 0.05). The droplets were tinier and evenly distributed, and the absolute xi-potential values and rheological characteristics reached their maximum at a catechin concentration of 20 mu mol/g. The formation of thiobarbituric acid-reactive substances and carbonyls declined significantly with the growth of catechin levels (P < 0.05), which confirmed that the oxidation of MPs and lipids was reduced efficiently by catechin. This study provides an idea for improving the emulsification and oxidation stability of MPDAG emulsions, which offers a theoretical basis for the application of MP-DAG emulsions in meat products.