Characterization of protease activity from hepatopancreas of blue crab

Abstract

Proteolytic enzymes play an important role in determining the quality of blue crab during postmortem storage. Activity of endogenous proteases is involved in the texture softening and autolysis of blue crab, which limits the customer acceptance and marketing price. This research aimed to characterize the protease activity of crude enzyme extract from the hepatopancreas of blue crab. The optimum activity of crude protease extract was found at pH 7.0 and 50°C. The crude protease enzyme was highly stable over a wide pH range of 4.0-11.0 and showed high stability at temperatures below 40°C. In addition, the protease activity continuously decreased with an increasing concentration of NaCl (0-15% w/v). Therefore, an understanding of the endogenous proteases in the blue crab could be used to develop appropriate storage methods during its distribution process.