Effect of Suitable Dietary Iron Supplement on the Fillet Quality，Surimi Stability and Cathepsin B/L of Jian Carp（Cyprlnus carpio var Jian）

Abstract:

To study the effect of suitable dietary iron supplement on the quality of fillet，surimi and Cathepsin B/L（CAT B/L） of Jian carp（Cyprlnus carpio var Jian）. The fish fed for 90 days with the supplemented diets containing iron of 146.1 mg/kg（suitable group） was collected as experimental group，and those fed without supplemented diets containing iron of 53.9 mg/kg（lacking group） was the control. After sampling，the quality indexes of fillets and the activities of CAT B/L were detected. Then the protein expression level of CAT B/L was quantified by immunohistochemical analysis. Further，the fillet was processed into surimi，and its stability of each group was measured. The results indicated that the MBF and MFI in suitable group increased or declined slightly（P>0.05） when compared to lacking group. While the shear force of suitable group increased 31.80%（P<0.01）；the contents of soluble collagen，insoluble collagen and the total collagen increased 305.45%，180.98%，219.35% respectively（P<0.01）. The pH and water loss rate of suitable group was in the trend of decline（P>0.05）. Moreover，the CAT B/L activities of suitable group was less than the lacking group to the degree of extreme significance（P<0.01） and significance（P<0.05） respectively. Meanwhile，the immunohistochemical analysis indicated that in both groups，CAT B/L were expressed in the muscle tissue and the expression level of suitable group was less than the lacking group extremely significantly（P<0.01）. Additionally it was found that suitable dietary iron supplement could increase the initial CA，TSH（P<0.01），and decrease the initial DB（0.01