수산식품의 단백질분해효소

Proteinase in seafoods

Proteases contained in seafood are important because they make a positive contribution to fermentations and other industrial processes and, on the other hand, can also be detrimental to the quality of raw and cooked fish and shellfish during chill storage or heat processing. Important groups of endogenous fish proteases include those originating from digestive organs, those present within the muscle cell, and enzymes synthesized and secreted in the extracellular matrix. Research has been undertaken to identify specific proteinases that cause problems like gaping, meat softening, and meat-gel softening in seafood. However, our current knowledge of proteinases and the specific way they contribute to quality loss in seafood is fragmented and incomplete. In recent years several new groups of proteinases have been identified in seafood tissues and long held concepts and mechanisms are being questioned. Examples of recently identified groups of proteinases include multicatalytic enzymes, neutral-heat activated proteinases, matrix metalloproteinases and ATP-dependent proteinases in fish muscle tissue. Other recent findings are that specific cathepsins can hydrolyse certain myofibril proteins at the natural pH of fish meat, that modori in cooked fish gels may not be caused by heat stable alkaline proteinases, and that despite the low content of connective tissue in aquatic organisms, degradation of collagen and other extracellular matrix components by endogenous proteinases may be detrimental to texture and appearance of seafood.