Study On Reduce High Acidity Of Prickly Ash Seed Oil With Esterification

In this study, the basic raw material was prickly ash seed oil, prickly ash seed oil was generally dark in color, and had higher acid value, the text targeted for decolorizing the prickly ash seed oil pertinencily, then refining oil by the way of acid esterification, finally depickling with esterificating the oil post-processing necessarily, that refined results were better.In the study of discolor process, activated carbon combined with activated clay as a mixed-decolorizing agent, focused on four decolorizing factors,including of activated carbon accounting for the mixed-decolorizing agent , mixed-decolorizing agent dosage,decolorizing time, and decolorizing temperature. Combining single factor experiment and response surface optimization experiments , ultimately optimum decolorizing conditions were as follow∶activated carbon accounting for the mixed- decolorizing agent 15.5% ; mixed-decolorizing dosage 2% ; decolorizing time 22min ; decolorizing temperature 93℃, under the optimum conditions,the decolorizing rate was 79.71%.In the study of depickling with esterification process , by comparing five traditional esterification catalyst screening,the results showed that the catalyst ZnO was the best. Selected ZnO as a catalyst for esterification, we used the reaction time on esterification, esterification temperature, the dosage of ZnO, the addition of monoglyceride / glycerine (1∶1,w/w) as the single factor experiment for observation and analysis of orthogonal test. Through orthogonal test analysis of single factor experiments combined with the situation, considering the effect on oil color by reaction temperature on the esterification and economic applicability,finally determined the optimal reaction conditions were as follows∶reaction temperature 200℃, the dosage of ZnO 0.2%,monoglyceride / glycerine (1∶1,w/w) content 150% of the theoretical value, under this condition, the acid ester oil price was 3.57mgKOH / g, the yield of monoglyceride and diglyceride in the ester oil were 3.25% and 13.64% respectively.In the post-processing of oil esterification,mainly purified triglyceride by solvent extraction, extraction conditions were as follow∶extraction solvent 85% ethanol concentration; ethanol / mixed oil (w/w) percentage was0.8∶1; extraction temperature 40℃, finally the content of triglycerides in monoglyceride was 0.88%, the content of diglyceride was 4.62%, acid value dropped to 1.73 mgKOH / g.