Effect of PH-Shifting Treatment on the Biochemical and Thermal Properties of Myofibril Protein

The pH-shifting treatment (including acid treatment and alkali treatment) caused partly denaturation and degrading of myofibril. The pH-shifting treatment increased the surface hydrophobicity, surface -SH content and total -SH content, reduced the Ca-ATPase activity. Acid treated myofibril (ACM) did not show any endothermic transition peak in differential scanning calorimetry (DSC); while alkali treated myofibril (AKM) showed reduced T max value for myosin and actin. The SDS-PAGE indicated that acid treatment caused severe degrading of myosin heavy chain. High turbidity of ACM indicated more myofibril aggregated during acid treatment. The final G’ was in the decline order of M (550 Pa), AKM (135 Pa), and ACM (25 Pa). In conclusion, the alkali treatment was milder than the acid treatment.