Effect of Changes in Biochemical Properties of Myofibrillar Proteins during Heat-drying on Texture of Dried Meat

Abstract

The relationship between changes in stiffness of dried meat and changes in some properties of the myofibril prepared from pork during heat-drying was investigated. Solubility of myofibril prepared from the dried meat, which was purchased in a market, with 0.6M KCl (pH 7.5) or with 8M Urea and 2% SDS (pH 8.0) was measured. Shear force values of dried meat were associated with the solubility of myofibril; the higher the shear force value of dried meat was, the less the solubility of myofibril was. When sliced pork was heat-dried at 50°C, the solubility of myofibril prepared from heat-dried pork with 0.6M KCl (pH 7.5) decreased with the increase of its shear force values, and the moisture content of sliced pork during heat-drying; Ca-ATPase activity and solubility with 0.6M KCl (pH 7.5) of the myofibril prepared from the sliced pork changed according to a first order reaction rate. The order of changing rates was the rate constant of inactivation of Ca-ATPase>that of decrease in solubility>that of decrease of moisture content. This fact suggested that contractile protein started to denature in the very early period of heat-drying treatment, and then moisture of sliced pork continuously started to decrease in this heat-drying condition. From these results, we assumed that texture of the dried pork would be tender, if denaturation of contractile protein of sliced pork would be prevented during heat-drying process.