Study On The Physicochemical Properties And Fish Jelly Processing Of Collagen From The Skin Of Puffer Fish(Tetrodontiformes Fasciatus)

Tetrodontiformes fasciatus rich in nutrition,and the skin is rich in collagen.With the development of toxic reduction technology,the market of T.fasciatus and Takifugurubripes has gradually opened.At present,its development and utilization were mainly focused on muscle,gonads,Toxin research,there was less research on the T.fasciatus skin,In order to enhance the added value of T.fasciatus and Enrich the market,it has a certain theoretical basis for the collagen of T.fasciatus skin,while developing high quality Puffer fish related product,a fish jelly of T.fasciatus.Collagen extracted from the skin of T.fasciatus by acid,hot water,pepsin,papain,and ficin were used to evaluate chemical and structural properties,respectively.In this study,characterization of collagen from T.fasciatus skin in term of the extraction yield,amino acid composition,Fourier transform infrared?FTIR?spectroscopy,ultraviolet spectroscopy?UV?,scanning electron microscopy?SEM?and sodium dodecyl sulfate-polyacrylamide gel electrophoresis?SDS-PAGE?.Results showed that the extraction yield of collagen obtained by pepsin was the highest,the amino acid compositions were similar and the contents were different,the content of proline in collagen extracted by 3 enzymes is significantly lower than that of collagen extracted by acid and hot water,FTIR showed collagen obtained by the five extraction methods had Amide A,Amide B,Amide I,Amide II and III,and confirmed the triple helical structure of the collagen,UV showed a strong absorption peak around 235nm,indicating a typical collagen when combined with FTIR,SDS-PAGE analysis confirmed that collagen in skin of T.fasciatus was type I collagen,and preparations by acid and pepsin retained protein structure while papain dissociated collagen and obtained protein with low molecular mass,SEM showed that extracted collagen by acid was most suitable for biomedical materials.Therefore,different extraction methods resulted in different chemical and structural properties of fish skin collagens.The molecular weight distribution of collagen extraction by different enzymes had obvious differences.According to research needs,different preparations are selected to develop collagen products.This study used T.fasciatus skin as raw material,through the process of hot water extraction,prepare fish jelly from the skin of T.fasciatus,determine the processing parameters of the fish jelly,based on single-factor experiments of extraction temperature,time and solid-liquid ratio,the collagen recovery and gel strength as indicators,applying response surface methodology to fish jelly rich in collagen and with good gel properties were optimized,and the amino acid composition and content were analyzed.The results showed that time,temperature and solid-liquid ratio had significant effects.Based on the collagen recovery and gel strength,two regression equations were obtained.The determination coefficients R²were 0.9597 and 0.8863,respectively.The P value of the missing term was greater than 0.05,indicating that both models were valid.The optimal process conditions were extraction temperature 81?,solid-liquid ratio 1:3.5and the extraction time was 2h.Amino acid results showed that the composition and content of fish jelly amino acids were consistent with skin,rich in glycine and characteristic amino acid,which could effectively utilize fish skin and retain nutrients.fish jelly is rich in collagen and having good gel properties was initially obtained,which provided a theoretical reference for the further development of products from the skin of T.fasciatus.In order to improve the quality of fish jelly from the skin of T.fasciatus,fish jelly was deodorized.Jasmine tea,Oolong tea,Citric acid-Ca Cl₂,and White vinegar-Liquor were respectively used to deodorize the fish jelly,After single factor,sensory assessment.According to the evaluation,better deodorizing conditions were obtained,3%Jasmine tea,50min and 50?,Oolong tea was added at 1.5%,30min,a 40?;0.5%citric acid,0.1%Ca Cl₂ was added,30min and 30?;the amount of white vinegar-Liquor was 1.5%,20min and 40?.SPME-GC-MS was used to analyze the volatile substances before and after deodorization.The original sample,deodorization of jasmine tea,deodorization of oolong tea,deodorization of citric acid-Ca Cl₂,and deodorization White vinegar-Liquor deodorization were detected 40,56,58,41and 51 kinds.The relative content of aldehydes is 16.08,2.16,3.60,8.61 and 6.64%.The smelly substances in the fish jelly may be hexanal,heptanal and Nonanal,trans-2-octenal,2,5-Heptanedione.Through sensory evaluation and GC-MS analysis,the fishy smell was significantly reduced after deodorization,and the main aldehyde irritating substances were significantly reduced.and the flavor of tea was increased.The comparison concluded that all three methods were certain the deodorizing effect of tea method is better than the deodorizing effect of Citric acid-Ca Cl₂ and White vinegar-Liquor.According to the results of this study,Jasmine tea flavor or Oolong tea flavor fish jelly can be made.This product Similar to Tortoise jelly,you can also use two other deodorizing methods to deodorize,and then conduct flavor research to make a variety of fish jelly products.Through the study of this paper,the physicochemical properties of skin collagen of T.fasciatus were studied.the processing parameters and deodorization of fish jelly from the skin of T.fasciatus were obtained.fish jelly is a product rich in collagen,strong gel properties and weakened fishy smell.