Authenticity Of Sea Buckthorn Oil Based On Ultra-Performance Liquid Chromatography Coupled With Quadrupole Time-of-flight Mass Spectrometry Technology

Sea buckthorn oil is rich in unsaturated fatty acids,tocopherol,β-carotenoids and sterols and so on,and it has good pharmacological and traditional effects.Therefore,due to its rich nutrition and high market value and many other reasons,sea buckthorn oil adulterated very seriously.The adulteration of sea buckthorn oil not only infringe upon the legitimate rights and interests of consumers,but also harm the health body and mind of consumers.There are only two kinds of authenticity identification technology has been reported to identified sea buckthorn oil,and both of them cannot to achieve its characterization of sea buckthorn oil and its adulterated oil in the detailed components.So far the study about the technology of UPLC-QTOF-MS(Ultra-Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry,UPLC-QTOF-MS)to distinguish the true nature of the sea buckthorn oil has not reported.The UPLC-QTOF-MS has the advantages of high throughput,high sensitivity,and can be used to detect a large number of trace compounds in edible oils,which has a great significance for the identification of the authenticity of edible oils.Therefore,in this study,we used the methods of lipidomics and metabolomics based on UPLC-QTOF-MS,and combined with PCA(Principal Component Analysis,PCA)and OPLS-DA(Orthogonal Partial Least Squares Discrimination Analysis,OPLS-DA)of chemometrics methods to identify the authenticity of sea buckthorn oil,and to use this methods to speculate the compounds which contained in the sea buckthorn oil and its adulterated oil(sunflower seed oil,rapeseed oil and soybean oil),and to explore the differences among various edible oils to further distinguish sea buckthorn oil and oil adulteration,and further to authenticate the map.The research contents and main results are as follows:1.Research on identification of UPLC-QTOF-MS lipidomics of sea buckthorn oilThe research based on UPLC-QTOF-MS lipidomics to test the glyceride in edible oil samples,can clearly distinguish the sea buckthorn oil and its adulterated oil.A total of 92 species of diacylglycerols(DAG)and triacylglycerols(TAG)has been detected,among them,16 species are diacylglycerols,76 species are triacylglycerols.The glycerides mainly in sea buckthorn but not exist in adulterated oil are:DAG32:1、TAG36:0、TAG38:0、TAG40:0、TAG42:1、TAG42:3、TAG44:5、TAG44:6、TAG46:0、TAG46:1、TAG58:6、TAG60:6 and TAG60:6.According to the measured glyceride,the model was established to characterize and predict the clustering differentiation of sea buckthorn oil and its adulterated oil.The authenticity identification of sea buckthorn oil,sunflower seed oil,rapeseed oil,soybean oil and different kinds of adulterated oil was realized.The results showed that the models of PCA and OPLS-DA had a good degree of differentiation and explain ability,and the clustering differentiation among edible oils was obvious.The various edible oils were separated in clusters.It can basically realize the effective distinction between different kinds of edible oil.The application of clustering analysis was used to compared the distribution and relative content of 92 glycerides in sea buckthorn oil and its adulterated oil by different colors,and the hierarchical clustering algorithm heatmap was used to compared the relative content of glyceride in edible oil straightly.The identification of sea buckthorn oil and its adulterated oil was predicted by using the prediction chart of observed value and predicted value,and the prediction proved that the method to detect sea buckthorn oil and its adulterated oil has good linear relationship and strong prediction ability,which can achieve the effective identification of each gradient of sea buckthorn oil and its adulterated oil rely on the production point and the measure data.It can provides support for solving the actual detection of adulteration concentration.2.Research on identification of UPLC-QTOF-MS non-target metabolomics of sea buckthorn oilWe used UPLC-QTOF-MS non-targeted metabolomics to detected the edible oils,and coupled with the methods of PCA and OPLC-DA to conducted the cluster differentiation of sea buckthorn oil and its adulterated oil.The MarkerView(Ver1.3.1 AB Sciex company)software and the SIMCA(Ver15 MKS Data Analytics Solutions(the original Umetrics))software were used to filtrate the characteristic ions.According to the conditions,we compared the chemical equation of compound,primary and secondary ion chromatogram with the online databases,MS-FINDER software and literature comparison to speculate the name of characteristic compounds,and to identify the verification of edible oil furtherly.The experimental data showed that the method which based on non-targeted metabolomics of UPLC-QTOF-MS can effectively distinguish the differentiation of sea buckthorn oil,sunflower seed oil,rapeseed oil and soybean oil.The chemical metrology model is reliable.OPLS-DA model clustering degree of differentiation is good,and it has the good explanation and prediction ability.The clustering of same kind of edible oil and the distinguish situation of different kinds of edible oil is clearly,it can effectively identify among the sea buckthorn oil and its adulteration oil.Through the analysis of characteristics of compound abundance,the 1%adulterated sea buckthorn oil can be identified,therefore on the basis of UPLCQTOF-MS of non-target metabolomics technology can be used as the one of the effective means to identified the sea buckthorn oil and its adulteration oil.It can provide experience and reference for the application of non-target metabolomics and chemometrics analysis technology based on UPLC-QTOF-MS for the authenticity identification of sea buckthorn oil and its adulterated edible oils.In this research,the non-volatile characteristic metabolic compounds of sea buckthorn oil and its adulterated oil were speculated.Through this way 20 characteristic compounds have been detected,which include organic acids and alcohols.10 of characteristic compounds are sea buckthorn oil,4 of characteristic compounds are sunflower seed oil,5 of characteristic compounds are rapeseed oil and 1 of characteristic compounds is soybean oil.Different kinds of edible oils have different characteristic compounds.Some characteristic compounds are only existing in sea buckthorn oil,such as Sclareol,Lobetyol,Ricinoleyl alcohol,Ursonic acid/Oleanonic acid and so on.Characteristic compounds can be used to distinguish 4 kinds of oil from the level of small molecules,explore the types of adulterated oil and to verify the map furtherly.Therefore,this method and model identification are mutually verified and complementary,which can be used as a good way to identify the authenticity of sea buckthorn oil and its adulterated oil and accurately determined the authenticity of unknown sea buckthorn oil samples.This way can provide solid identification theory and scientific basis for the identify of sea buckthorn oil,and provide certain experience and reference for the late application through this method to verify the sea buckthorn oil and adulterated edible oil.