Optimization Of Preparational Sericin From Penyi Silk And Study On Biological Activities

As a kind of natural textile materials in China,Pernyi Silk enjoys the fame of the"Fiber Queen”,which is composed of the inner layer of silk fibroin and outer sericin protein.And silk fibroin is a kind of tough and elastic protein contents of pernyi silk is about 70%-80%,and the sericin protein is one kind of globular protein,soluble in water,contents of pernyi silk is about 20%-30%.Due to the needs of silk making and textile process,cocoon needs degumming process.Through the cocoon cooking,silk reeling,spinning,refining,and dyeing processes,many silk dyeing factory in our country get such silk fibroin and applied to the clothing or silk quilt,and a large amount of sericin protein are discharged along the wastewater in cocoon cooking process.At present,China's silk production is200000 tons a year and about 30000 to 40000 tons of sericin protein loss and in the world speaking 400000 tons of silk can be produced every year,about 80000 tons of sericin protein loss.However it's around 300-350 yuan per kilogram of sericin protein.So the factory wastewater recycling and utilization of sericin protein research has a certain economic benefits.At present,sericin protein didn't get enough attention and utilization.The development of sericin protein in China and other countries are all at laboratory's research stage,and lack of sericin protein's industrialization preparation and making technology is also one problem.To solve these problems,this study optimized sericin protein preparation and making process,focusing on pilot enlarge research,by using two tons of industrial wastewater treatment,break the earlier laboratory preparation and making in small scale's history.Realize industrial production and provide technical support and security.This study uses pernyi silk as the experimental material,optimize sericin protein preparation technology,including the pernyi silk degumming process and degumming liquid of sericin protein extraction technology,the simulated industrial soap alkaline degumming process,optimizing the papaya protein enzymatic degumming process,analysis of acid chromatography,organic solvent method,salting out method extracting sericin protein ability size,determine the best pernyi silk sericin protein preparation process.On this basis,using wastewater from the factory and enzymatic degumming liquid to have pilot enlarge research,preparing and making plant wastewater sericin protein powder,and the enzymatic degumming sericin protein powder,to analyze the physical and chemical indicators?including heavy metal analysis,amino acid composition analysis and the analysis of the health indicators?with biological activity?oxidation resistance,anti-tyrosinase's activity,ultraviolet resistant activity,moisturizing and suppression of cancer cells in vitro activity?.Detailed experimental results are as follows:1.Pernyi silk sericin protein preparation and making process optimization:Simulated industrial soap alkaline degumming process,and use enzyme activity,degumming time,initial pH,degumming temperature for design L9?3⁴?orthogonal test,optimization of papaya protein enzymatic degumming process,prepare and making degumming liquid.By using analysis of acid chromatography,organic solvent method,salting out method extracting sericin protein in degumming liquid capacity.Results show that the traditional industrial soap alkaline degumming practice reduction rate was 15.6%,and 14.9%protein content.After degumming pernyi silk‘s color is dark yellow,agglomerate,and if stretch,it's easily to fracture.COD is 1.0×10⁴,BOD₅ is 1.1×10³,papaya protein enzymatic degumming process best for enzyme activity 7×10⁵U,time 2 h,pH8,temperature 75^oC.Under the papaya protein enzymatic degumming process the best practice reduction rate can reach up to19%,protein content 18.6%,after degumming pernyi silk is white and fluffy,resilient,not easy fracture.COD is 5.2×10³,BOD₅ is 9.7×10²,sericin protein in degumming liquid extraction process method of organic solvent extracting sericin protein is better than acid chromatography and salting-out method,extraction yield is 69%,ethanol concentration to be 75%,extraction rate was 75%for 90%'s ethanol and concentration is dose dependent effect.Based on the pattern of industrialization and also considering the cost benefit.Eventually choose sericin protein extracted in 75%ethanol for degumming liquid.2.Pilots enlarge research and physical and chemical indicators,biological activity research:According to the actual demand of industrialization,using the optimized preparation process for silk dyeing plant industrial wastewater and enzymatic degumming liquid's pilots enlarge research,prepare plant wastewater sericin protein powder and the enzymatic degumming of it.And totally dealt with 2 tons plant wastewater,got sericin protein 1123 g,break the laboratory small scale's research history,to provide technical support for industrialized production.And the preparation of both kinds of sericin protein's amino acid are mainly consists of serine,glycine and aspartic acid,total content as high as 55%and above.And both heavy metal's content and health indicators are in line with the national standard.On this basis,evaluate the oxidation resistance,tyrosine enzyme activity,ultraviolet resistant,moisture and the in vitro cancer cell activity and biological activity of two kinds of sericin protein,to explore the influence of different preparation processes of sericin protein biological activity and carries on the comparison of both biological activity abilities.Results show that both DPPH free radical removal ability and hydroxyl radical scavenging ability were dose-response effect,when the concentration reaches 2 mg/mL,the DPPH free radical removal ability were 62%and 74%respectively,hydroxyl radical scavenging ability were51%and 57%respectively,anit-tyrosinase activity inhibition rate were 18%and 27%respectively.In moisture absorption experiments,both within 24h moisture absorption ability growth was positively associated with time,after the balance hygroscopic rate is about 26%.In moisture test,the moisture ability of the two kinds of sericin protein within 2hours before both are over 80%,when balance,both moisturizing ability are 40%;Factory wastewater sericin protein in maximum absorption peak wavelength of 287nm,the absorbance value of 0.612,SPF 4.43;sericin protein enzymatic degumming in maximum absorption peak wavelength of 287 nm,the absorbance value of 0.906,SPF 9.40,both have good resistance to UVA and UVB;for gastric cancer cells?823?the best inhibitory rate of 48%and 51%respectively,the best inhibitory rate of liver cancer cells?HepG2?were 59%and 62%respectively.Compare in two kinds of sericin protein biological activity ability,the enzymatic degumming of sericin protein oxidation resistance,resistance to tyrosine enzyme activity,resistance to ultraviolet sericin protein is much better than the factory wastewater sericin protein and moisturizing effect,ability to inhibit cancer cells in vitro are similar.To sum up,this research in view of the low utilization rate of pernyi silk sericin protein,optimization of sericin protein preparation,pilot enlarge research,evaluation of sericin protein biological activity.It not only solved the environmental pollution,sewage treatment and other issues,but also use sericin protein as a great development and utilization of resources at the same time,for its functional food,health care and cosmetics,functional materials and other new industries provide security and theoretical basis for the further application,has far-reaching significance to increase economic efficiency and realize the added value of the sericin protein.