Study On Physical And Chemical Properities Analysis And Refining Process Of Lanolin

Lanolin,is enriched in many functional components,which has important applications in the pharmaceutical and household chemical industries.wool resource is abundant and used to produce crude lanolin in China.The refining process is limited due to emulsification,washing difficulties,low yield and high waste water,etc.There is a little researches in the refining of the recovered crude lanolin,which limited the application of lanolin and caused resources waste.The aim of this study is to investigate the problems in the lanolin refining process,to optimize the process conditions to obtain good quality lanolin,which can provide some theoretical support for the use of lanolin in the pharmaceutical and cosmetic industries.Firstly,main physicochemical parameters and main components of lanolin were investigated.And the results shown that the melting point,saponification value and peroxide value of lanolin met the requirements of pharmacopoeia grade refined lanolin.However,the colour,odor,moisture,volatile matter content,ash content,acid value and iodine value didn’t meet the requirements of pharmacopoeia grade refined lanolin standard.The total ester content of lanolin is about 82.44%,which resulted in low purity of lanolin.The main compositions of lanolin are cholesterol and lanolin,their content is 44.31%and 14.62%respectively.The lanolic acid was mainly saturated fatty acids with long carbon chain lengths(C₁₃～C₂₇),with branched chain acids containing up to 62.03±0.27%.And triglycerides were not detected in lanolin.Secondly,solvent extraction and mixed oil alkali refining deacidification were used to deacidify the raw lanolin.Compared two deacidification methods,a suitable deacidification process was selected,and the effects of the deacidification process conditions（solvent type,mixed oil concentration,excess alkali addition,alkali concentration,alkali refining temperature and alkali refining time）on the acid value,yield and soap content of the lanolin were investigated,and the optimum deacidification process was optimized by orthogonal experiments and soap removal conditions were optimized under the optimum deacidification process conditions.The results were shown that the lanolin oil blend was suitable for deacidification.The optimum conditions of deacidification and subsequent removal of residual soap were 55%mixed oil concentration,20%super alkali addition,14°Be（?）lkali concentration,70°C alkali refining temperature,30 min alkali refining time,1:0.5 lanolin to 95%ethanol（v/v）,washing 7 times.Under the optimal conditions,The yield was 70.05±1.15%,the acid value was reduced to 0.24±0.05 mg/g,the soap content was reduced to 0.65±0.08%and the ash content was reduced to 0.11±0.01%,which was accordance with the pharmacopoeia grade lanolin and cosmetic internal control standards.The process was based on the mixed oil alkali refining method of animal and vegetable oils,which reduced solvent consumption during alkali refining.95%ethanol was used for washing and desaponification,avoiding the emulsification and water waste.However,the color of the lanolin was dark（Gardner colour13）,so decolourisation was necessry.Lastly,deacidified lanolin as raw material to screen the decolorization process,the hydrogen peroxide decolorization process was determined.And the effects of the decolourisation process conditions（hydrogen peroxide addition,decolourisation temperature and decolourisation refining time）on the peak area,yield,acid value and peroxide value of the lanolin were investigated.The optimal conditions were:3%hydrogen peroxide addition,55°C decolourisation temperature and 50 min decolourisation time.Under the optimal conditions,lanolin color peak area was 30.56±0.74,yellow color（Gardner color 11⁺）,the yield was 95.32±0.30%and the acid value and peroxide value were little increased,but all met the requirements of the pharmacopoeia grade lanolin standard.Under optimal conditions of the refining process,Continuous deacidification and decolourisation experiments of crude lanolin were performed.And 0.33±0.01 mg/g of acid value,yellow colour（Gardner colour 11⁺）and 66.86±0.24%of lanolin yield were obtained.The lanolin obtained under this refining process is of good quality and all the physicochemical indicators meet the pharmacopoeia grade refined lanolin standard.