| Camellia oil and rapeseed oil are main edible oils in Jiangxi province,not only rich in unsaturated fatty acids,but also natural bioactive compounds,such as vitamin E and polyphenols.In recent years,with the continuous improvement of people's living standards,people have high requirements for the quality of oil and fat food,and these food need to be controlled by testing methods with more advanced,accurate,quick and convenient.Because of the complexity of components,it is very difficult to analyze their chemical components effectively by single detection method.It is necessary to combine various analytical technologies.For this paper,components of camellia oils and rapeseed oils were analyzed and identified by UPLC,GC,SPME-GC-MS,UPLC-QTOF-MS and chemometrics.Chapter 1: The chemical constituents of camellia oils and rapeseed oils were introduced,and the research results of various analytical techniques were also described,including the advantages of physical and chemical testing methods,GC,GC-MS,UPLC,UPLC-MS,nuclear magnetic resonance spectroscopy,spectroscopy,fingerprints and chemometrics methods were applied in the analysis of vegetable oils.Chapter 2: The nutrient compositions including vitamin E,polyphenols and fatty acids in camellia oils and rapeseed oils,and they were analyzed by using UPLC,GC and colorimetric assay.The results showed that only the ?-tocopherol was measured in camellia oils,and the content was 1.516-25.536 mg/100 g.Four kinds of vitamin E were detected in rapeseed oils,and the content of ?-tocopherol was the highest,33.903-64.790 mg/100 g,the content of ?-tocopherol was 7.847-28.467 mg/100 g,and the content of ?-tocopherol was 2.904-7.769 mg/100 g,the content of ?-tocopherol was 1.326-2.713 mg/100 g,and the contents of total vitamin E were 47.822-98.738mg/100 g.The contents of vitamin E in traditional crude oils is significantly higher than that in refined oils.The contents of fatty acids in camellia oils and rapeseed oils were different,and the contents of some fatty acids,such as C16:0,9cC18:1,9c12cC18:2 and 9c12c15cC18:3 in rapeseed oils were higher.The content of fatty acid C16:0 was 30.933-79.892 mg/g,the content of 9cC18:1 was 252.621-587.744mg/g,9c12cC18:2 was 130.042-366.554 mg/g,9c12c15 c C18:3 was 28.981-98.106mg/g.The contents of some fatty acids such as C16:0,9cC18:1 and 9c12cC18:2 in camellia oils were higher,and the content of C16:0 was 34.895-94.904 mg/g,thecontent of 9cC18:1 was 505.977-805.538 mg/g,9c12cC18:2 was 54.575-169.195mg/g.The contents of polyphenols in camellia oils were 4.824-45.170 ?g/g,the contents of polyphenols in rapeseed oils were 10.994-248.234 ?g/g,and the total content of polyphenols in rapeseed oils was higher than camellia oils,and crude oils contain more polyphenols,which decreases with increasing degree of refining.Chapter 3: The volatile aroma components of camellia oils and rapeseed oils were extracted by solid phase microextraction.At the same time,the volatile aroma components were identified by GC-QQQ-MS,and the experimental method was optimized.54 kinds of volatile components in rapeseed oils were identified,and 51 kinds of volatile components in camellia oils were identified.Through the study of the principal component analysis,it was found that camellia oil and rapeseed oil can be distinguished significantly.There were significant differences in volatile components in two vegetable oils,the contents of isovaleraldehyde,heptanal,3-propylcyclohexene,(E)-2-heptenal,2-pentyl furan,limonene,3,5-octadien-2-ol,2-nonanone,2-decanone,dodecane,decanal,tridecane,(E,E)-2,4-decadienal,1-pentadecene,hexadecane were higher in camellia oils,and the contents of 3-pentenenitrile,4-methyloctane,erucic acid,isodecane,3-butenyl isothiocyanate,methyl heptenone,2-propanyl furan,4-methyl decane,3-ethyl-2,5-dimethylpyrazine,hydrocinnamonitrile,1-heptatriacotanol,(±)-cembrene were higher in rapeseed oils.Chapter 4: In this experiment,the fingerprints of camellia oils and rapeseed oils were established by the similarity evaluation system of Chinese medicine chromatographic fingerprint with HPLC and GC.In the gas chromatography fingerprints of camellia oils and rapeseed oils,there were 25 common components in rapeseed oils and 18 common components in camellia oils.In the liquid chromatography fingerprints of camellia oils and rapeseed oils,there were 25 common components in rapeseed oils,and 13 common components in camellia oils.Chapter 5: UPLC-ESI-Q-TOF/MS was used to analyze camellia oils,rapeseed oils,adulterated camellia oils and oil samples by heating.Combined with chemometrics software MPP,the unsupervised analysis methods,such as principal component analysis(PCA),volcano plot analysis and hierarchical cluster analysis were used to classify camellia oils,rapeseed oils,adulterated camellia oils and oil samples by heating,and these different components in the four kinds of vegetable oils were obtained.And the four kinds of vegetable oils model was constructed by the supervised partial least squares discriminant analysis method(PLS-DA),theprediction accuracy was 100%,and through validation we can see that the model was credible. |
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