Research On High Efficient Preparation And Anti-Radiation Activity Of Unsaturated Fatty Acids In Tea Seed

With the rapid development of industrialization and information technology,the electromagnetic radiation from information transmission,radio tools and various household appliances and the ubiquitous ultraviolet radiation in the environment are endangering people’s health.Seeking a natural,safe and efficient anti-radiation skin care oil to protect modern people against radiation hazards have important epochal significance.Tea seed is a mature seed of Camellia sinensis plant,as the world’s largest tea producing country,China has rich tea resources,but for a long time,tea seeds usually as a by-product of tea production and mostly abandoned in the tea garden.Studies shows that tea seeds oil contains more than 51%monounsaturated fatty acids（oleic acid）,about 27%polyunsaturated fatty acids（linoleic acid）,about 21%saturated fatty acids（palmitic acid and stearic acid）,with the protection of the heart,hypoglycemic,regulating blood lipids and other biological activity,in addition,its chemical composition is similar to the body surface fatty acid composition,so it’s an ideal material of radiation-resistant skin care oil and other high-value product.In this study,fresh tea seeds as raw material,followed by tea seeds unsaturated fatty acid retention method selection,the supercritical extraction process optimization,ester exchange and molecular distillation separation and purification process optimization and unsaturated fatty acid ethyl ester emulsified oil anti-UVB radiation activity and so on,with a view to provide scientific basis for the efficient development and utilization of abundant tea seeds resources in China.The main findings are as follows:（1）Drying method optimization.With fresh tea seeds as raw material,through the comparative study on indoor air-dried,sun drying and electric hot air drying three kinds of drying effect on tea seed retention rate of unsaturated fatty acids,optimizing the drying method of high reserves unsaturated fatty acid.The results showed that the indoor air-dried effect is the best,followed by the sun drying;considering a simple indoor air-dried method has longer time,higher moisture content of tea seeds and other factors,optimizing the first indoor air-dried and then electric hot air drying method.Under this method,the fatty acid composition of tea seed as follow:55%oleic acid,26%linoleic acid,15%palmitic acid,3%stearic acid and 0.8%docosanoic acid.（2）Supercritical extraction process optimization.The tea seeds were dried and shredded into40 mesh.Single factor experiment,orthogonal experiment and verification experiment was used to optimize the process of unsaturated fatty acids supercritical CO₂ extraction.The results showed that the factors affecting the extraction yield of unsaturated fatty acids were as follows:extraction temperature>extraction time>extraction pressure,the extraction temperature had significant effect（P<0.05）.The optimum extraction technology was extraction pressure 25MPa,extraction temperature 45℃,separation temperature 55℃,CO₂ flow rate 20³0 kg/h,165 min.Under this condition,the yield of unsaturated fatty acid was 8.77%and the purity of unsaturated fatty acid was 80.30%.Compared with traditional Soxhlet extraction,the yield of unsaturated fatty acids was 6.02%and the purity of 79.67%,increased by 2.75%and 0.63%,respectively.（3）Ester exchange and molecular distillation separation and purification process optimization.With supercritical fluid extraction of tea seeds oil as raw material,after dealing with the ester exchange,molecular distillation single factor experiments,the effects of the rate of injection,the speed of film,the degree of vacuum and the effect of distillation temperature on the yield and purity of unsaturated fatty acids were investigated.The optimum process of molecular distillation is preferred by orthogonal experiment and confirmatory test.The results showed that the order of four factors impact on the yield and purity of unsaturated fatty acids was vacuum degree>sampling rate>scraping film speed>distillation temperature.The optimum process conditions were:distillation temperature 110℃,vacuum degree 1?10-²mbar,scraping film speed100r/min and feed rate 20-30 drops/min.Under this condition,the yield and purity of unsaturated fatty acid are 79.20%,80.29%,respectively.（4）Study on anti-UVB radiation activity of unsaturated fatty acid ethyl ester.People formed epidermis cutin cell HaCaT cells as the experimental object.The effects of unsaturated fatty acids on the survival of HaCaT cells irradiated by UVB were studied by emulsifying the unsaturated fatty acid ethyl ester obtained by molecular distillation and separation.The results showed that the addition of unsaturated fatty acid ethyl ester in the cell culture medium significantly improved the cell viability,indicating that unsaturated fatty acids have a protective effect on UVB-damaged HaCaT cells.