The Identify Of Edible Oil Adulteration By GC

Edible oil contains the important nutrients, which the human body can notsynthesize and lack. It provides the body with essential fatty acids, and it is one ofimportant food for human body. Types and contents of the adulterated edible oil’s fattyacids changed, and it will seriously harm to human health. At present, the commonadulteration phenomenon in the market is put cheap oil into expensive oil. In order toidentify better the edible oil adulteration, this study proposed the method of using fattyacid databases combined with the computer program to identify adulterated oil.In order to accelerate oil hydrolysis, reduce resource and energy consumption, usingmicrowave ultrasonic coupling technology to hydrolysis the oils. The influences of themicrowave power, ultrasonic power, temperature and time on hydrolysis were discussed.The results show that when the microwave power is500W, ultrasonic power is300W,temperature is60℃, radiation time is8min, the acid value can reach to the maximum acidvalue and this is the optimal hydrolysis condition.After hydrolyzed and methyl ester disposed, the oil is analyzed by gas chromatograph.The conditions: choose strong polarity capillary column of WondaCAP WAX（30m×0.25mm i.d.,0.25μm film thickness）, carrier gas: N2, pressure90kPa, split ratio:100:1,hydrogen pressure40kPa, air pressure40kPa, injector temperature was240℃and detectortemperature was260℃, sample volume:1μL.The temperature program: the initialtemperature is70℃, and keep it for2min,5℃/min up to180℃, keep2min, and then1℃/min up to205℃, keep1min, then3℃/min up to225℃, keep for10min. Under thiscondition, the fatty acids can get better separation.It is truly response characteristics of the oil to use the types and contents of fatty acidsas oil’s evaluation standards. Summarized the common oil’s fatty acid data which aremeasured by predecessors and this experiment, build into a database, and then compiledinto a corresponding program. Just input the oil fatty acids data, it will automatically matchthe sample to determine whether it is pure or not, and calculate the adulteration quantity.