Study On The Characterization Of Collagen And Bioactive Peptides From Cyprinus Carpio Haematopterus Scale

China is the largest country in production freshwater fish. And the Cyprinus carpio haematopterus is a common kind of freshwater fish. Fish scale, which are relatively rich in collagens, are directly discarded into the environment, which not only wastes resources but also pollutes the environment. Collagen and gelatin, as well as bioactive peptide can be obtained from Cyprinus carpio haematopterus scale. It can be not only reducing environment pollution but also making full use and comprehensive utilization of fish scales. At the same time, the new product based on fish scale may improve fish value.This study investigated the pre-treatment technology, collagen extraction technology, collagen structure, properties and gelatin extraction technology of Cyprinus carpio haematopterus scale. And the antioxidant activities, the tyrosinase inhibition activities and the effects on melanin content in B16melanoma cell of Cyprinus carpio haematopterus scale gelatin digestion.First, it investigated the pre-treatment technology of Cyprinus carpio haematopterus scale. It investigated the effects of various processing parameters on demineralization of Cyprinus carpio haematopterus scale. It was observed that the HCl solution can Effectively removing the minerals of fish scale. It was concluded that the optimum conditions were as follows:extraction time of95min, concentration of HCl of1.0M, and ratio of material to solution of11mL/g. It investigated the effects of NaOH on deproteinization of Cyprinus carpio haematopterus scale. And the optimum conditions were as follows:extraction time of26h, concentration of NaOH of1.0M, and ratio of material to solution of11mL/g.The properties and structure of Cyprinus carpio haematopterus scale collagen were studied. The results suggested that the collagen of Cyprinus carpio haematopterus scale classified as type I collagen. Combined with the results of SDS-PAGE, the collagen was (al)2α2or ala2a3trimers. FTIR investigations showed that the existence three helical conformation of PSC. There is no difference of major structure of PSC and ASC indicates that the structure of Cyprinus carpio haematopterus scale collagen could not be destroyed by pepsin. The denaturation temperature of ASC and PSC of Cyprinus carpio haematopterus scale were31.4℃and31.8℃respectively, and the shrinkage temperature were52.9℃and55.3℃respectively. Futhermore, the solubility of fish scale collagen were affected by pH value and salt concentration. And the isoelectric point of ASC and PSC were at about pH7.The gelatin extraction technology of Cyprinus carpio haematopterus scales were studied. The investigated parameters were extraction temperature, ultrasonic time, ultrasonic power and ratio of solvent to solid. The optimum extraction conditions were found to be:optimized extraction temperature70℃, ultrasonic time100min, ultrasonic power300W and ratio of solvent to solid10mL/g.It investigated the simulated gastrointestinal (GI) digestion of Cyprinus carpio haematopterus scale gelatin. A two-stage in vitro digestion model system (a pepsin treatment for2h followed by a pancreatin treatment for2h, both at37℃) was used to simulate the process of human gastrointestinal (GI) digestion to determine the digestibility of fish scale gelatin. The results showed that there is very low digestive power of pepsin on a chain and β chain of scale collagen compared with pancreatin. And the final degree of hydrolysis of GI digests was16.9%. The changes in antioxidant activities and tyrosinase inhibition activities of fish scale gelatin during simulated gastrointestinal (GI) digestion were studied. The results suggested that the antioxidant activities and tyrosinase inhibition activities of fish scale gelatin correlates with the degree of hydrolysis.The digests Cyprinus carpio haematopterus scale gelatin were fractionated into three ranges of molecular weight (JCP1>3000Da,1000Da<JCP2<3000Da and JCP3<1000Da) using ultrafiltration technique. The antioxidant activities of fish scale gelatin digests were studied. JCP3showed the highest hydroxyle radical and superoxide anion radical scavenging abiliity, reducing power and chelating ability of Cu2+. The hydroxyle radical scavenging and superoxide anion radical scavenging IC50of JCP3were0.57mg/mL and1.01mg/mL respectively. And JCP2has strong activity to eliminate DPPH radical, while JCP2and JCP3have similar inhibitory activity of a linoleic acid lipid peroxidation system.The tyrosinase inhibition activities of fish scale gelatin digests were studied. The results indicated that JCP3has the strongest inhibitory ability on the steady-state monophenolase activiey of tyrosinase, and the IC50to monophenolase activiey of tyrosinase was75.24μg/mL. The different molecular weight fish scale gelatin digests showed inhibitory ability on the diphenolase activiey of tyrosinase, and the tyrosinase inhibition activities were related to their concentrations use. JCP3showed the strongest inhibitory ability on the diphenolase activiey of tyrosinase, and the IC50to diphenolase activiey of tyrosinase was51.11μg/mL.The pharmacodynamics effect of Cyprinus carpio haematopterus scale gelatin digests on the mouse B16melanoma cells was studied. The results showed that the digests could markedly improve the proliferation of the mouse B16melanoma cells and had no cytotoxic activity. The effect of JCP3on melanin biosynthesis of the mouse B16melanoma cells and the molecular mechanism were investigated from the aspects of antioxidant. The results indicated that Cyprinus carpio haematopterus scale gelatin digests exerted marked inhibition on productions of melanin and the activity of tyrosinase. And the Cyprinus carpio haematopterus scale gelatin digests exerted marked inhibition on productions of melanin and the activity of tyrosinase. And the pharmacodynamics effect of Cyprinus carpio haematopterus scale gelatin digests could maintain the GSH levels of cells. Besides, it could decrease intracellular levels of GSSG and cAMP significantly.