Effect of dietary protein on muscle collagen, collagenase and shear force of farmed white shrimp (Litopenaeus vannamei)

The effect of three protein sources (sardine-based diet, squid-based diet and commercial diet) in feed on white shrimp (Litopenaeus vannamei) growth, muscle collagen, collagenase activity and shear force was determined. Shrimp fed on diets with squid and sardine protein exhibited greater growth (p<0.05) than those fed with commercial feed. Shrimp muscle collagen obtained from each treatment group showed similar molecular weight to that of bovine collagen type I as determined by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE). Denaturation thermograms by differential scanning calorimetry (DSC) for shrimp collagen showed a transition peak at 47°C, whereas that for bovine collagen type I was 65°C. The lowest enthalpy of transition was detected in collagen from shrimp fed on squid. The highest muscle collagenase activity was detected in shrimp fed with commercial feed. After 10-day ice storage, muscle from shrimp fed commercial feed required somewhat less shear force than those fed with sardine-based and squid-based meal. The results suggest that the source of protein influences the enthalpy of transition of collagen from shrimp muscle, collagenase activity, and texture in shrimp tail meat as well as growth rate.