[Objective]The quality of oil prepared by different methods is slightly different.Traditional cold pressing process has low cost,and the oil extraction can avoid the damage of nutrients at high temperature or the organic solvent residue caused by solvent extrac-tion,but the disadvantage is low oil yield.For example,extraction of oil meal with supercritical CO2 fluid can improve the oil extraction rate.In this paper,the physicochemical parameters and main nutrients of cold-pressed walnut oil and walnut meal after supercritical CO2 fluid extraction were analyzed and compared.[Method]The oil of walnut oil from Aksu region of Xinjiang was extracted by cold pressing method,and then the oil meal was extracted by supercritical CO2 fluid extraction method to extract the remaining oil.The physicochemical indexes and the content of main nutrients of two kinds of walnut oil were analyzed according to the national standard method.[Result]The physicochemical indexes of walnut oil extracted by the two methods were in line with the national standard requirements,and the acid value and peroxide value were lower.The fatty acids in the two oils were the same,with little difference in content.A total of 8 kinds of fatty acids were detected,mainly linoleic acid,oleic acid and α-linolenic acid,among which the linoleic acid content was the highest,all of which were more than 62％,and the total amount of unsaturated fatty acid(UFA)reached more than 90％.The polyunsaturated fatty acid(PUFA)content was more than 75％.Among the major elements,the potassium content of walnut oil extracted by supercritical CO2 fluid extraction was 6.83 mg/100g and 2.87 mg/100g,respectively.The analysis of trace elements showed that the iron content of walnut oil extracted by supercritical CO2 fluid extraction was higher than that by supercritical CO2 fluid extraction,0.71 mg/100g and 0.10 mg/100g,respectively.Analysis of other vitamins and phytochemicals showed that the content of vitamin E in walnut oil extracted by cold pressing method was higher than that by supercritical CO2 fluid extraction method,while the content of β-sitosterol and squalene in walnut oil extracted by supercritical CO2 fluid extraction method was lower than that by cold pressing method.[Conclusion]Walnut oil extracted by the two methods has good physical and chemical properties,little difference in the content of main nutrients,rich in PUFA and vitamin E,high nutritional value,and the two methods complement each other.
walnut oilfatty acidmineral substancesqualeneβ-sitosterolvitamin E
维普
万方数据
