Preparation And Characterization Of Tilapia Scale Collagen And Polysaccharide Composites

Collagen is a natural polymer material with abundant content and wide sources in nature.It has the advantages of anti-radiation,hypoallergenic,low antigenicity,film-forming,biocompatibility and degradability.However,its poor thermal stability and mechanical properties have also become the most fatal shortcomings,limiting its wider application.Synthetic polymer materials have the characteristics of low price,good mechanical properties and superior performance.Therefore,in this study,the fish scales,a by-product of the processing of tilapia,a regional dominant aquatic product,were selected as raw materials,and the collagen was extracted by a combination of enzyme extraction and hot water extraction.Three polysaccharide-collagen composites.Finally,character characterization was carried out to evaluate its application potential in biomedicine,packaging materials and meat product preservation,and provide a scientific basis for further development of new functional collagen composite materials.The main contents and results obtained in this paper are as follows:(1)Collagen-collagen composite gel,agar-collagen composite gel and gelatin-collagen composite gel were prepared by using three substrates of keratin,agar and gelatin to compound collagen.The effects of different materials on the structure and properties of composite gel materials were studied.The results show that the keratin-collagen composite gel prepared by compounding 15% keratin and 70% collagen in a volume ratio of 1:1 has good biocompatibility,optical properties,mechanical properties and good biocompatibility.Gel characteristics;after 300 s of UV light irradiation,the survival rate of Escherichia coli under the protection was 62.06±0.75%;through the simulation experiment of human epidermal fibroblasts,it was measured in the keratin-collagen composite gel material.Under the protection,the damage degree of cells after 120 min of UV lamp irradiation was the least,and the cell death rate was 22.75±0.06%.It is further demonstrated that the keratin-collagen composite gel has good anti-ultraviolet radiation ability,and the material is expected to be applied in the in vitro protection of the human body in the medical diagnostic equipment with radiation.(2)Make use of chitosan and pullulan as the base material,polyvinyl alcohol(PVA)as the modifier,compounding with collagen in a certain proportion,and using the casting film-forming method to prepare various composite films.The results showed that the pullulan/chitosan/collagen ternary composite membrane was prepared by mixing 5% pullulan,chitosan and PVA with 10% collagen in a volume ratio of 1:1:1:1 The physicochemical properties and structural properties have significant advantages.The thickness is 142.50±1.06 μm,the tensile strength is 11.21±2.64 MPa,the elongation at break is 169.24±5.69%,the expansion ratio is 368.16±12.49%,the solubility is 58.64±1.24%,and the water vapor transmission rate is 0.23±0.07 g·mm/m2·h·k Pa,the opacity is 2.28±0.07 UA/mm.The transmittance,Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction spectroscopy(XRD)and scanning electron microscopy(SEM)analysis of the film show that the film has good UV blocking ability,and each component forms A homogeneous system with a dense structure is formed,the interaction force and hydrogen bonds are generated between the molecules,and the crystalline strength is small,and it has good biocompatibility.The film is expected to become a new type of packaging material.(3)Make use of chitosan and collagen as raw materials,and using propolis extract as antioxidant,a variety of preservatives were prepared by mixing in a certain way.The results showed that the compound preservative prepared by mixing 2% chitosan,10% collagen and 0.5%propolis extract in equal volume had the best preservation effect on sashimi.When refrigerated for 12 days,the indicators are: p H value of5.44±0.02,volatile base nitrogen(TVB-N)value of 18.7±0.11 mg/100 g,thiobarbituric acid reactant(TBARS)The value was 0.43±0.02 mg/kg,and the total number of colonies was 4.42±0.07 lg MPN/g.By measuring the color,hardness,elasticity and chewiness of sashimi,it was found that the compound preservative treatment was more conducive to maintaining good brightness and texture quality of sashimi,and was more acceptable to consumers.The composite preservative is expected to be applied to the refrigerated preservation of meat food.