Abstract: The effect of sodium pyrophosphate (TSPP) on the oxidation and dissociation of actomyosin was investigated together with the influence on the effect of adenosine triphosphate (ATP) in dissociating differently oxidized actomyosin. Results showed that TSPP could inhibit the oxidation of actomyosin by 1 mmol/L H2O2, but have no obvious inhibitory effect on actomyosin oxidation by 10 and 20 mmol/L H2O2. After being treated separately with TSPP and ATP, the intrinsic viscosity of non-oxidized actomyosin decreased by 30.4% and 41.9%, and the average particle size by 21.2% and 48.4%, respectively. After being treated sequentially with TSPP and ATP, the intrinsic viscosity and average particle size of non-oxidized actomyosin increased to some extent. ATP induced a slightly greater change in the relative viscosity of the oxidized samples than that of the nonoxidized samples. However, the increase in the relative viscosity was weakened by TSPP treatment. Undissociated fibrous actomyosin existed in TSPP treated samples with and without ATP treatment, forming large aggregates upon oxidation. In general, TSPP was far less than effective in dissociating actomyosin than ATP, and even it had an inhibitory effect. Oxidation could promote the dissociation of ATP to a certain extent, but this effect was inhibited by TSPP. The results provide a theoretical basis for applying TSPP for improving the quality of meat products.

Key words: actomyosin; sodium pyrophosphate; oxidation; dissociation; adenosine triphosphate