Identification And Analysis Of The Quality Of Natural Peppermint Oil,Ginger Oil And Olive Oil

Natural peppermint,ginger oil and olive oil are important raw materials of food,cosmetics and other industries.With the improvement of living standards,better quality of these oils is required more than ever before,and the price is also increased.Lack of quality control,oil adulteration occurres frequently,which damages to the consumers seriously,and poses a threat to import and export trade of peppermint,ginger oil and olive oil.Currently,researches on quality identification of essential oil and olive oil are not comprehensive.In order to guarantee consumers' right and health,a rapid and sensitive method should be proposed for the detection of essential oil and olive oil,based on the analysis of compound components.It has important practical significance for quality control of peppermint,ginger oil and olive oil goods.This research is focus on the detection of peppermint,ginger oil adulterated with plant oil and the sterol components in olive oil,the main contents and conclusions are as follows:1.Methyl ester derivatization and Gas chromatography-mass spectrometry were used to identify the peppermint oil and ginger oil adulterated with plant oil and mixed oil.The component of six kinds of plant oil and mixed oil were discussed.Based on the different of the total ion chromatograms between adulterated and un-adulterated samples,fatty acids were found as endogenous markers.The results show that: Non-peppermint oil and non-ginger oil ingredients are detected in adulterated peppermint oil and ginger oil after methyl esterification,including stearic acid,linoleic acid,oleic acid,palmitic acid,the compounds' retention times are mainly distributed in 18 ~ 20 min.More than 0.001% plant oil and mixed oil can be detected in peppermint oil and ginger oil by this method.2.Based on the established model of peppermint oil adulteration of plat oil and mixed oil.The levels of the adulteration of the plant oils(W)can be inferred based on the peak area ratio of four kinds of characteristic fatty acid totally and L-menthol(S1/S2).The results show that: S1/S2<0.015,W<1%;0.015?S1/S2?0.182,1%?W?5%;0.182<S1/S2?0.501,5%<W?10%;0.501<S1/S2?1.043,10%<W?20%;S1/S2>1.043,W>20%.The method is sensitive,reliable,and provides an important technical basis for the peppermint oil,ginger oil quality and safety control.3.According to the GB/T25223-2010 method-<< animal and vegetable fats and oils-determination of individual and total sterols contents –gas chromatographic method>>,the pretreatment of olive oil were improved.The optimized conditions of sample pretreatment are set as follows: sample: 0.25 g;potassium hydroxide soluble in ethanol: 0.5 mol/L;reaction temperature: 100 ?;unsaponifiable matter solvent: N-hexane.The optimized conditions of sample purification are set as follows: Solid phase extraction column: HLB column;leacheate: 1.5 mL hexane,eluent: 5 mL n-hexane and methylene chloride mixture(v/v,1:1).4.With the analysis of sterols in olive oil by gas chromatography mass spectrometry,improved pretreatment method and the method of GB/T25223-2010 were discussed by analyzing nine olive oil samples,using gas chromatography.The results show that: there is no obvious difference between the results of the two methods,and three unqualified samples are detected by using improved method.