Study On The Extraction Of Korean Pine Nut Oil By Supercritical CO₂

Korean pine nut is rich in nutrition with oil content up to60percent. In this paper, toobtain Korean pine nut oil with low acid value and low peroxide value, Korean pine nut wasextracted by supercritical carbon dioxide. The extraction was optimized by the modifier todevelop the efficiency, and antioxidants were added to slow down oxidation. GC analysismethod with high column efficiency was determined. PUFAs were enriched by urea including,the optimum parameter of the craft was determined and the rule of the enrichment wasstudied.The factors affecting extraction yield including extracting pressure, modifier, extractingtemperature, and extracting time. Under different conditions （15MPa and35MPa,45℃）,extraction rate and extraction ratio of Korean pine nut oil was compared to determine whetherto use the modifier. The physicochemical indexes of Korean pine nut oil were determined.The POV was used to evaluate the stability of pine nut oil. Antioxidant properties of TBHQ,PG and mixed antioxidants （zingiber extractive and citric acid） were respectively evaluatedin pine nut oil by Schaal-oven method. The urea addition, alcohol addition, the time and thetemperature of clathration were the four parameters to investigate. The optimum parametersof enriching pinolenic acid from Korean pine nut oil were determined and studied in themixing operation of Korean pine nut oil and evening primrose oil.The optimum parameters of extracting oil from Korean pine nut were35MPa,45℃,240min,5%free-water C2H5OH as modifier. The rate of CO₂flow was20²5L/h. Modifiercan improve extracting efficiency. The indexes of the Korean Pine Nut oil were as follows,acid value of0.43, iodine value of140.47, saponification value of197.41and peroxide valueof1.30. Korean Pine Nut oil extracted contained linoleic acid of47.46%, oleic acid of28.14%,pinolenic acid of14.80%, myristic acid of4.41%and soft oleic acid of2.28%. In theexperiment of antioxidant effect, TBHQ was better than mixed antioxidants and mixedantioxidants were better than PG. In urea incluing, the optimum ratio of fatty acid to urea toalcohol was1:3.5:8, the temperature and the time of clathration was5℃,10hours.The yieldof polyunsaturated fatty acid was11.69%, and the content of pinolenic acid was improved from14.80%to85.92%. The results showed that the optimum parameters of enrichingpinolenic acid from Korean pine nut oil could be considered to include fatty acids whosecarbon numbers, the level of unsaturation and the bent of carbon chain were lower thanpinolenic acid, and these fatty acids appeared shorter than pinolenic acid in gaschromatogram.