Partial Characterization of a Collagenolytic Enzyme Fraction From the Hepatopancreas of the Freshwater Prawn, Macrobrachium rosenbergii

Abstract

Textural changes of freshwater prawn during ice-chilled/refrigerated storage are believed in part to be due to an autolytic process. A collagenolytic enzyme fraction, isolated from the hepatopancreas of the freshwater prawn, was most active at 37°C and pH 6.5-7.5 and was also active at 0"C. The addition of this enzyme fraction to prawn tissue increased the hydrolysis of prawn collagen at O'C for 96 hr indicating that this enzyme fraction might be responsible for the textural change in prawn during ice-chilled storage.

Changes in the ultrastructure and texture of prawn muscle (Macrobrachuim rosenbergii) during cold storage

“…Several studies show that the texture of prawn changes during storage, as measured by both sensory and instrumental techniques (Angel, Weinberg, Juven, & Lindner, 1985;Lindner, Angel, Weinberg, & Granit, 1988;Srinivasan, Xiong, Blanchard, & Tidwell, 1997;Srinivasan, Xiong, Blanchard, & Tidwell, 1998). Typically, refrigerated prawn has a shelf life of 3-4 d (Nip, Lan, & Moy, 1985), although some suggest that the shelf life could be as long as 1 week (Angel et al, 1985;Lindner et al, 1988).…”

“…One hypothesis proposes that mushiness is due to proteolytic activity of the hepato pancreas in the tail muscle (Baranowski, Nip, & Moy, 1984;Lindner, Angel, Weinberg, & Granit, 1989;Lindner et al, 1988;Nip, Zeidan, & Moy, 1981), resulting in the degradation of prawn muscle (Nip et al, 1985;Kimura & Tanaka, 1986). Hepatopancreas extracts contain both peptidase and proteinase activity, and include aminopeptidase, carboxypeptidases A and B, cathepsin C, chymotrypsin, and collagenases (Garcia-Carreno, Hernandez-Cortes, & Haard, 1994).…”

Post mortem muscle protein degradation during ice‐storage of Arctic (Pandalus borealis) and tropical (Penaeus japonicus and Penaeus monodon) shrimps: a comparative electrophoretic and immunological study

“…Summarised, the changes described include: decreased levels of ATP, with corresponding increases in ADP, AMP, IMP, 5±8 adenine and hypoxanthine; 9 and autolytic degradation starting in the hepatopancreas, 10 with the consequent release of proteolytic and collagenolytic enzymes from this organ that induce the development of mushiness in the muscle. 11,12 The structures most resistant to degradation are muscle, connective and cuticular tissues. 10 Papadopoulos et al, 13 in freshwater prawns, and our group, 14 in P borealis, reported the appearance and increase with storage time of fragments of molecular size 67± 180 kDa which were attributed to increased solubilisa-tion and degradation of myo®brillar proteins.…”

Effect of Blanch Time on the Development of Mushiness in Ice‐Stored Crawfish Meat Packed with Adhering Hepatopancreas

“…The presence of hepatopancreas tissue in other crustaceans has been implicated in similar textural problems (Papadopoulos and Finne, 1985;Lightner, 1973). Collagenolytic enzymes from crustacean hepatopancreas tissue, partially characterized by Nip et al (1985), were found to degrade tail meat and collagen gels (Eisen and Jeffrey, 1969;Baranowski et al, 1984). The presence of similar enzymes in crawfish hepatopancreas could be expected to degrade the texture of crawfish meat as well as gelatin (amorphous collagen).…”