| Cornus wateri has a broad development and utilization prospect as an excellent oil tree and landscape tree,is a new type of woody oil,the oil content as high as 36% 38%.Based on the extraction rate of Cornus wateri oil,we choosed the best Species form four kinds of Cornus wateri seeds by useing Soxhlet extraction.This oil was a raw material for the study of the following: Cornus walteri oil was extracted by Soxhlet extraction and supercritical CO2 extraction,respectively;Under the optimum conditions,oil were extracted and were compared with heating-crushing cold-processedin under the state of colour and lustre,extraction rate,and the acid value and other indicators;The decoloration of alkali was studyed integrati,which realized the caustic refining and decoloring at the same time,leaving out the decoloring steps of oil refining;we used GC-MS to analysis Cornus wateri Crude oil、degummed oil、neutralized oi1 and bleached oil,in order to study the main fat acids,stability.1.This research mainly used Cornus wateri seeds as main material,through exploring the extracting process of oil from the Cornus wateri,we found out the best way to extract it.Through orthogonal experiment design,the best condition of extraction was as follow:ratio of solid and liquid was 1:5 and react 115 min at 65 ℃.Under these conditions,extraction rate increased to 37.12%.2.We used ethanol to be the carrying agent of CO2 to extract the Cornus wateri seed oil in supercritical state,which realized the oil extraction and decoloring at the same time,leaving out the decoloring steps of oil refining.Through orthogonal experiment design,the best condition of extraction was as follow:the ratio of liquid to solid is 1 ︰0.9 g/m L,temperature is 40 ℃,pressure is 16 MPa and the frequency is 21.3 HZ.In this parameter,the extraction ratio was up to 38.85% and absorbancy was 0.203.3.The extraction rate of organic solvents is as high as 37.12%,but the color is deep er and the absorbance is 0.720.So the followed process is complex.Since the oil have impurities and is close to black by the method of heating-crushing and cold-proces sed,it will not be adopted.The extraction rate of supercritical CO2 extraction is the high est,at 38.85%,the absorbance is 0.203,the sample have good color and its acid value is as low as 8.45.Compared with other methods,the supercritical carbon dioxide extraction showed many advantages,such as short extraction time and high extraction yield,but the upfront input is too heaven,difficult toclean and maintenance in convenience.After negotiating with partners,the ultimately method of extraction is solvent extraction.4.The best bleaching conditions were at 65 ℃ with 0.8 mol /L of sodium hydroxide,alkali refining twice in a scale of 1﹕1,tegration and added 4.5% of activated clay,The absorbancy was 0.399,the acid value was 0.234.Then it bleached 60 mins by carclazyte in the stirring speed of 320 r/ min at a temperat ure of 70 ℃.The absorbancy was decreased to 0.198 from 0.720,and the acid value was decreased to 0.256 from 10.92.5.In the four stages of the refining process,Cornus wateri oil all contains palmitic acid、 palmitoleic acid、oleic acid、inoleic acid、stearic acid trans-oleic acid.Crude oil contains palmitic acid（30.12%）、palmitoleic acid（3.64%）、oleic acid（27.84%）、inoleic acid（29.00%）、stearic acid（2.02%）、 trans-oleic acid（6.38%）、 trace amounts of pentadecanoic acid（0.11%）and eicosanoic acid（0.16%）.Among the se fatty acid,the pentadecanoic acid and eicosanoic acid was unstable species,which dispersed in degummed oi1、neutralized oi1 and bleached oil.The relative am ount of palmitoleic acid、oleic acid and inoleic acid were all in a stable state.The relative amount of palmitic acid and stearic acid were slowly rising,representing a stable status.To conclude,Cornus wateri oil was stable and reached the standard of the quality requirements. |
