Effects of sodium pyrophosphate coupled with catechin on the oxidative stability and gelling properties of myofibrillar protein

The influence of a combination of sodium pyrophosphate (PP) and catechin (C) on the gelling properties of pork myofibrillar protein (MP) under oxidative stress was investigated. The addition of PP or C significantly inhibited lipid oxidation and protein carbonyl formation, and their combination (PP + C) provided the maximum protection. However, these additives did not prevent sulfhydryl and free amine losses caused by oxidation. The presence of PP in the oxidizing system reduced the mean particle size and elevated zeta potential and solubility of MP, reduced cooking loss, and improved breaking strength of MP gels (P < 0.05). Environmental scanning electron microscopy revealed a fine and smooth microstructure within the set gels of oxidized MP treated with PP, similar to non-oxidized MP control gels. The incorporation of C produced no definitive effect on the gelling behavior of MP under oxidation condition except reducing whiteness. The PP + C treatment resulted in an overall improvement of MP gelling capacity and structural integrity of the gel. Hence, enhanced oxidative stability and gelling properties of MP can be attained through PP coupled with catechin.