Proteolytic Profiles of Walleye Pollack (Theragra calcogramma) and White Croaker (Pennahia argentata) Meats in the Presence of Intestinal Extracts from Their Own or Different Fish Species

Meat homogenates and intestinal extracts were prepared from walleye pollack (Theragra chalcogramma) and white croaker (Pennahia argentata). Then, the proteolytic profiles of meat homogenate in the presence of the intestinal extracts were determined. The proteolytic activity in the intestinal extracts from walleye pollack was the maximum at 50°C and pH 8.53. The maximum activity was recognized also at 50°C when the intestinal extracts from walleye pollack were added to the meat homogenate prepared from white croaker, while it was at 60°C when the intestinal extracts from white croaker were added to the meat homogenate prepared from walleye pollack. These results suggest that the proteolytic profile is predominantly attributable to proteolytic enzymes and not to the substrate species of myosin heavy chain. These findings are useful for managing heating conditions in the industry in order to avoid modori and thus improve the quality of surimi-based products.