Study On Preparation And Application Of Collagen From The Swim Bladders Of Grass Carp (ctenopharyngodon Idella)

To make more effective use of underutilized fish waste materials,acid-soluble and pepsin-soluble collagens (ASC and PSC) were extractedfrom the swim bladders of grass carp (Ctenopharyngodon idellus) byacetic acid and pepsin. The paper studied the optimization technology ofthe extraction of collagen from the swim bladders of grass carp andcharacterized the properties of them. Finally, the preparation of collagensponge were investigated. The research results are as follows:The effects of liquid-solid ratio, acetic acid concentration andextraction time on the yield of acid-soluble collagen(ASC) from the swimbladders of grass carp were optimized by statistical analysis usingresponse surface methodology on the basis of the single-factor test. Inaddition, the mathematical model describing the relationship between theyield and parameters was developed. The optimal conditions for higheryield of ASC were a liquid-solid ratio of 17.85, an acetic-acidconcentration of 0.54M and a time of 34.0 h. Under these conditions, themodel predicted a ASC yield of 8.39％.The composition, structure and properties of ASC and PSC werestudied and compared with each other. The UV spectra and FTIRinvestigations showed that the distinct absorption was obtained near230nm, and maintained their triple helical structures well. The amino acidprofiles of ASC and PSC revealed that the contents of hydroxyproline andproline were 16.87% and 17.55%, respectively. SDS-PAGE patterns aswell as CM-Toyopearl 650 M column chromatography indicated that bothASC and PSC comprised at least two differentα-chains (α1 andα2), whichis similar to the porcine typeⅠcollagen. Peptide maps of collagens (ASCand PSC) digested by proteinase K revealed that ASC was moresusceptible to hydrolysis than PSC and there might be some differences in their primary structure in terms of amino acid sequence. Differentialscanning calorimetry (DSC) spectra of ASC and PSC showed that thethermal stability of ASC is better than PSC. The denaturationtemperature(Td)of ASC and PSC were 33.0℃and 34.8℃, respectively ,about 3-4℃lower than that of the porcine skin collagen (37℃). Theseresults suggest that the collagens from the swim bladders of grass carphave potential as an alternative or a supplementary source of collagenfrom land vertebrates for use in various fields for industrial purposes.Preparation technology of collagen sponges were studied.Theeffects of collagen concentration, pH value and additional dosage ofchitosan on the water absorption capacity and tension strength of collagensponges. Collagen sponges could be successfully prepared as awell-distributed films with the collagen concentration of 0.5﹪-3.0﹪.Thecollagen sponges obtained the higher water absorption capacity andtension strength when the ratio of collagen to chitosan is 6:4 at pH6 withthe collagen concentration of 2％.