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Study On Extraction And Characterization Of Collagen From The Fish Scale Of Grass Carp (Ctenopharyngodon Idellus)

Posted on:2006-01-29Degree:MasterType:Thesis
Country:ChinaCandidate:C JinFull Text:PDF
GTID:2121360155976659Subject:Food Science
Abstract/Summary:PDF Full Text Request
In this study, the procedure for the extraction of collagen, hot water extraction of gelatin and production of peptides by enzymic hydrolysis from the fish scale was developed. The fish scale was from fresh water fish species—the grass carp fish as the pilot case study. The whole research was aiming at developing a feasible procedure for effective utilization of fish scale and making certain the optimum conditions. At the same time, some important physics and chemistry characters of the extractives were also studied. The research results were as follows:1. Acid-soluble collagen (ASC) and pepsin-solubilized collagen (PSC) were extracted from fish scale with acid and enzyme methods. The result showed that the electrophoresis spectrum and FTIR analysis spectrum of extracted collagens were similar to those of the standard collagen. From amino acid analysis, I concluded that ASC and PSC were typical type I collagen. The maximum absorption of ASC and PSC were 233nm on ultraviolet spectrophotometry. Determination of denaturation temperature (Td) was expressed by measuring solution viscosity at several temperatures and Td of PSC was 25.7℃. The shrinkage temperature of ASC and PSC was 99.6℃ and 81.7℃ respectively by means of differential scanning calorimetry.2. After collagen has been collected from fish scale, gelatin was extracted from the residue of fish scale by hot water. The optimal conditions were found by single factor experiments and orthogonal tests as follows: extracting temperature 90℃, extracting time 3h, ratio of substrate and solvent 1:100. Some major functional properties of fish scale gelatin were studied. The results showed that the gelatin had high water absorption, water retention, foaming, foam stability and emulsification. In addition, some theological properties of the gelatin were studied. The viscosity of gelatin solution increased with the rise of the concentration and decreased with the rise of the sample temperature. When the concentration of CaCl2 was added to 0.5% in the gelatin solution, the viscosity of the solution came to a head. Under acidic conditions, the viscosity of the solutions changed notably; in pH7 solution, the viscosity came to a climax; under alkaline conditions, the viscosity decreased a lot. By the TPA test, it was found that he gelatin had low capability for gel forming at high temperature or low concentration.In addition, the effect of the different concentrations of fish scale gelatin on the Silver Carp surimi products was investigated. The results showed the addition of fish sscale gelatincould enhance the water-holding ability of silver carp surimi gels(P<0.05), and the higher the concentration, the more effective; the addition of fish scale gelatin could increase the whiteness of the products(P<0.05). On the other hands, the hardness, chewiness, resilience and springiness of the surimi gels were weakened with the addition of the gelatin(P<0.05), and the cohesiveness did not changed notably(P>0.05).3. After the process of extracted collagen and gelatin, papainase was chosen as the hydrolytic enzyme of the residues through the experiment. Then the optimal conditions of hydrolysing the residue with papainase had been found by single factor experiments and orthogonal tests as follows: temperature 65 °C, ratio of enzyme and substrate 1:10, time 4h and concentration of substrate 2%.
Keywords/Search Tags:Grass carp, Fish scale, Type I collagen, Enzymic hydrolysis, Extraction
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