Study On Extraction,Fatty Acid Profiles And Volatile Compounds Of Elaeagnus Mollis Diels Seed Oil

This study addressed Elaeagnus mollis Diels seeds as raw materials of Elaeagnus oil extracted through Ultrasound-Assisted Extraction（UAE）.Firstly,Effects of different solvents were investigated on the yield,antioxidant activities and fatty acid compositions of Elaeagnus oil.Secondly,effects of UAE conditions on the yield of Elaeagnus oil were probed,and subsequently the optimal parameters were achieved by orthogonal experiments.Finally,fatty acid profiles and volatile compounds in Elaeagnus oil as well as some common edible vegetable oils were studied through GC/MS,respectively,from which the characters of Elaeagnus oil were analyzed.The main results were as follows:（1）The oil content of Elaeagnus mollis Diels seeds was 50.87%by Soxhlet Extraction.There were differences among Elaeagnus oils extracted through different solvents.The oil yields in a descending order were:hexane,ethyl acetate,acetone,dichloromethane and diethyl ether.All of the above oils were clear and transparent except those by acetone and ethyl acetate.Through DPPH and ABTS radical scavenging assay,the DPPH antioxidant capacities of Elaeagnus oils in an descending way were through acetone,ethyl acetate,hexane,dichloromethane,supercritical fluid CO₂ and diethyl ether.DPPH antioxidant properties of Elaeagnus oils obtained by different solvents were obviously various.However,the discrepancies among ABTS antioxidant activities weren’t that remarkable.Through GC/MS analysis,there were few differences in fatty acid compositions among Elaeagnus oils extracted by disparate solvents.However,compared with Elaeagnus oil through supercritical fluid CO₂,the contents of a-linolenic acid and oleic acid in Elaeagnus oil through UAE were 0.5%and 1.5%higher.（2）Hexane used as the extraction solvent,factors affecting the yield of Elaeagnus oil in a descending order were liquid to material ratio,extraction time,ultrasonic power and extraction temperature.The optimal parameters for UAE of Elaeagnus oil were determined as follows:liquid to material ratio 8:1mL/g,ultrasonic power 90W,extraction temperature 50℃ and extraction time 20 min.Under this condition,the yield of Elaeagnus oil was 48.90%.（3）Through GC/MS analysis,fatty acid compositions were detected in nine edible vegetable oils,including Elaeagnus oil,rapeseed oil,flaxseed oil,sesame oil,peanut oil,corn oil,sunflower seed oil,soybean oil and olive oil.The contents of unsaturated fatty acids of Elaeagnus oil,rapeseed oil,flaxseed oil all reached over 90%,the others 79.3～85.5%.Besides,the contents of a-linolenic acid in flaxseed oil,rapeseed oil,Elaeagnus oil and sunflower seed oil were 39.94%,14.22%,7.11%and 5.65%,respectively.According to the information that the best intake ratio ofω-6/ω-3 polyunsaturated fatty acids was 4～6:1,the ratio ofω-6/ω-3 fatty acids in Elaeagnus oil（6.33）was the nearest to 4-6:1.Classification and proximity showed that olive oil,rapeseed oil and flaxseed oil had low proximity with each other and with the other vegetable oils.Moreover,Elaeagnus oil,sesame oil,peanut oil,corn oil,sunflower seed oil,and soybean oil had high proximity of over 0.85 with each other.The fatty acid compositions of Elaeagnus oil were the most similar to those of sesame oil.（4）163 volatile compounds in eight edible vegetable oils,including Elaeagnus oil,rapeseed oil,flaxseed oil,sesame oil,peanut oil,corn oil,sunflower seed oil,and soybean oil,were investigated through HS-SPME-GC/MS,including acids,aldehydes,alcohols,ketones,hydrocarbons,ethers,degradation of glucosinolates,pyrazines,furans,aromatic compounds,phenols,pyrroles,pyridines,pyrans,thiazoles,esters and other compounds.Differences of main volatile compounds from these edible vegetable oils were analyzed and evaluated.