Preparation Of Rabbit Hair Keratin And Its Application In Ultraviolet Protective Health Care Products

China's rabbit hair industry has a history of nearly a hundred years of development,is a traditional rabbit hair power.Every year,a great deal of rabbit fiber is discarded during processing,which is a serious waste of resources.Abandoned rabbit hair fiber rich in keratin,is a very rich natural renewable polymer materials,the way to achieve change is to disassemble the waste of rabbit hair fibers,extract and recycle the use of keratin.Rabbit hair protein is a high-quality keratin,which is a kind of keratin protein with high practical value.Its amino acid content is rich and varied,especially rich in aromatic amino acids and hydrophilic groups such as amino and hydroxyl.Rabbit hair keratin in the field of daily cosmetics has a good application prospects.Keratin extraction has been reported in many literatures at present.However,it is not easy to control the molecular weight distribution,molecular weight,and extraction rate of keratin,and these values are very important for the application of keratin.Therefore,the work of keratin extraction method is still being explored,which is a research hotspot in the field of keratin.First of all,in this study,L-cysteine was used as the reductant and urea as the main reagent for the first time.The effects of different factors on the dissolution rate and the recovery rate of keratin were investigated by orthogonal and single factor experiments.A new method of extracting rabbit keratin is optimized to improve the rate of rabbit hair fiber dissolution and keratin recovery.According to the optimal process,the dissolution rate of rabbit hair fiber was 77.78%,and the recovery rate of rabbit hair keratin was 68.02%.Its extraction is better than sodium bisulfite and mercaptoethanol reduction system,in the extraction of keratin has a great advantage.Secondly,the structures of the samples were characterized by Fourier transform infrared spectroscopy(FITR),Raman spectroscopy(RAM),X-ray diffraction(XRD),differential scanning calorimetry(DSC),Kjeldahl method and elemental analysis,SDS-Gel electrophoresis analysis of the best technology to extract the rabbit hair keratin structural and characterization.The results showed that the content of keratin in the sample after extraction was between 89%and 91%.The relative molecular mass of rabbit keratin mainly distributed in 11-22kDa.Compared with rabbit hair fiber,the content of ?-helical structure in the secondary structure of rabbit hair keratin decreased,While the content of ?-sheet structure increased,L-cysteine destroyed the disulfide bond between rabbit hair fiber molecules during the process of dissolving rabbit hair fibers.Finally,the first use of rabbit hair keratin powder as a cosmetic substrate,prepared a natural UV protection health products,respectively,the sensory and physical and chemical indicators,heavy metal content,sunscreen efficacy test.The test results showed that:the sample paste is delicate,the separation of non-water oil is not stratified;the content of heavy metals is lower than the national standards,which is in line with the hygiene standards of cosmetics of the People's Republic of China;the 15%rabbit hairdressing sun-The average absorbance A is 1.3735,belongs to the medium UV protection effect,suitable for medium intensity UV irradiation.