Visceral Protease Activity of Short Bodied Mackerel (Rastrelliger Sp.) at Different pH and Salt Concentrations

Abstract

This research was conducted in the Laboratory of Biochemistry, Faculty of Mathematics and Natural Sciences, University of Riau and Department of Public Works Riau Province in November 2011 to March 2012. This study aimed to evaluate visceral protease activity of short bodied mackerel at different pH and salt concentration. Mackerel weighing ± 150 g/each were obtained from a fish market in Pekanbaru. Fish were transported to the laboratory; and at the laboratory, the fish were eviscerated and their visceral organs (intestines, kidneys, liver, spleen, cord, pancreas and gonad) were blended in buffer Tris-HCl and filtered for their crude extract. The protease activity was measured at pH 6.0, 7.0, 8.0, 9.0, 10.0 and 11.0 and salt concentration 0%, 3%, 6%, 9%, 12% and 15%. The results showed that the protease activity varies with pH value and salt concentration. Protease activity at pH 11.0 showed the highest activity. The protease activity decreased with increasing salt concentration.