The molecular characteristics of shrimp collagen make it more susceptible to deterioration through the action of proteolytic enzymes than collagen of higher animals. Proteolytic action increases the lability of shrimp collagen toward heat induced solubilization. Degradation of connective tissue attaching the musculature to the shell during post-catch storage is responsible for enhancing the shell removal function of mechanical peelability. The powerful systems of the shrimp itself and, upon extended storage, the proteases of spoilage micro-organisms are the source of this activity. Unfortunately, this action also unfavorably alters musculature proteins with regard to the yield function of mechanical peelability.
Muscle proteins become more soluble after extended storage.
Connective tissue, because of its instability toward proteolytic attack, is predominantly involved. The rate and degree of deterioration depends on storage temperatures and on how long the shrimp are kept in storage. Deterioration of the shrimp muscle system enhances the water-holding capacity of shrimp meat through steam precooking. This is reflected in increased cooked meat moisture contents as post-catch ice storage is extended. Under the same steam precooking times and temperatures, meat moisture content can increase to an extent that dry matter losses are not reflected in cooked meat yield wet weight.