The Preparation Of Soft Collagen Jelly And Antioxidant Activity

China is a big country of meat consumption,but also the largest producer of pork and related food,pig skin are very rich in resources,but the pig skin is a large number of abandoned due to the bad smell and not easy to digest.Skin jelly is a traditional pig skin processing food which is not promoting to industrialization due to poor water retention and not easy to keep.Therefore,it is of great significance to study and develop new pig skin collagen protein food,improve its nutritional value and prolong product storage period.In this paper,pig skin was used as the raw material which to be hydrolyzed with trypsin and analyze the antioxidant activity of the enzymatic solution of pig skin.The enzymatic solution was separated by ultrafiltration to different molecular weight proteins,analyze the difference of the content and antioxidant activity.Pork skin hydrolyzate as the main raw material,add accessories?carrageenan,konjac flour,sugar and citric acid?by the heat-induced gel.The preparation of soft collagen jelly is optimized the processing of collagen jelly techno logy by orthogonal experiments;besides,the effects of different sterilization conditions?pasteurization,high temperature sterilization and autoclaving?on the quality and antioxidant activity of collagen jelly were studied.Finally,the quality analysis and evaluation methods of collagen were established,dermine the shelf life.The results are as follows:The results showed that the antioxidant activity of porcine skin after trypsin hydrolysis was strong,and the IC₅₀ of DPPH·and·OH was 5.30 mg/mL and 12.50mg/mL,respectively.,The reduction ability of Fe³⁺was dose-dependent relationship with the concentration of the enzyme solution.The proportion of the protein with molecular weight>50kDa was the largest,67.24%,the smaller the molec ular weight,the smaller the proportion;the antioxidant activity of different molecular weight proteins showes that the protein solution with molecular weight less than 5 kDa,the DPPH·,OH scavenging rate and the reducing power were the strongest,the IC₅₀ values were 4.10mg/mL and 4.20mg/mL respectively,and the protein with molecular weight greater than 50kDa had the worst antioxidant capacity.2)The preparation of soft collagen jelly shows that:the pig skin enzyme solution was used as the main raw material,,adding carrageenan and konjac gum to made a low-calorie,nutrition and healthy collagen jelly food with high melting point,good elasticity,good chewing.The optimum formulation of collagen was as follows:the concentration of compound rubber?carrageenan:konjac flour=3:1?2.5%,14%white sugar,0.1%citric acid.3.Effect of sterilization conditions on the quality and antioxidant activity of collagen:high-pressure sterilization significantly increased the b*value of collagen?p<0.05?,the color was yellowish,the hardness,gel and chewiness were significantly decreased,Pasteurization and high temperature sterilization can significantly improve the texture of collagen protein,the hardness and chewiness values were 478.24 and 135.86 after high temperature sterilization,which has no significant difference with commercial jelly?hardness 487.74,chewiness 137.65?.Rheological properties of the study found that:collagen jelly have shown the phenomenon of shear thinning after ster ilization,non-Newtonian fluid.High-pressure sterilization has a good effect on the shear resistance of collagen,and high temperature sterilization and pasteurization are not obvious.When the scanning temperature was under65?,G'and G''rapid decline,and then tend to gentle,high pressure sterilization will reduce the elastic behavior and viscous beha vior of collagen.After the treatment of different sterilization methods,the main molecular weight of the protein was still higher than 50kDa,and the high temperature sterilization could significantly increase the content of small and medium protein?<5k Da and 5k-10kDa?.After the sterilization treatment,the antioxidant capacity of DPPH was enhanced,IC₅₀ was 0.042 g/mL,the IC₅₀ of OH scavenging ability of the high temperature sterilization group was 0.093 g/mL.The reducing power of high temperature sterilization treatment group?the value was 0.369?has no significant difference with high-pressure sterilization?the value was 0.368?.Comprehensive consideration,high temperature sterilization can better maintain the color and texture of collagen jelly,protein tends to small molecule distribution,and can improve its antioxidant activity.4).The quality analysis,evaluation and shelf life of soft collagen jelly:The soft collagen jelly which were preparaed by the process of optimizing was creamy white,tasted soft and delicious with sweet and sour moderated.Protein content of 5.28%,collagen content of 1.46%,about 28%of total protein content,nutrient-rich.Heavy metals,the total number of colonies,coliform bacteria and other tests are in line with relevant national standards.Storage at room temperature?25??for 175 days?...