The Research On Enrichment Of Polyunsaturated Fatty Acids In Sweet Almond Oil

More primary products and less deep processing of high value-added products were the main problems of the sweet almond oil processing industry in Xinjiang, which was researched in this paper. In this study, sweet almond oil was chosed as the test material to research the technical parameters of the transesterification and molecular distillation for the polyunsaturated fatty acids of sweet almond oil, so as to provide some technical support. The main results were as followed:(1) The factors effected the pre-treatment of the enrichment of polyunsaturated fatty acids by molecular distillation—preparation of sweet almond oil fatty acids ethyl ester, the optimum process parameters determined through the Box-Behnken design and optimization of Design Expert 7.1.6 software were:the catalyst concentration was 1.0%, the alcohol oil ratio was 8.4:1, the reaction temperature was75℃, the reaction time 130min. Under this condition, sweet almond oil transesterification rate was 94.697%.(2) The mian factors effected the key technology—molecular distillation were researched. The optimum process parameters determined under 60drops/min through the Box-Behnken design and optimization of Design Expert 7.1.6 software were:distillation temperature was 109℃, operating pressure was 3Pa, scraper speed was 350r/min. Under these conditions, the content of PUFAs was 93.883%. In addition, the effection of distillation stages to the polyunsaturated fatty acid content was researched, the higher of thedistillation stages, the higher content of the polyunsaturated fatty acids, but the yield was reduced accordingly.(3) Not only the polyunsaturated fatty acids of sweet almond oil were enriched, but also the acid value and peroxide value were reduced, iodine value was increased by the molecular distillation, the quality of sweet almond oil was enhanced conspicuous.These results showed that, as a mature technology, the molecular distillation technology could be applied to solve the enrichment of polyunsaturated fatty acids in the sweet almond oil deep processing industry.