超高效液相色谱-高分辨质谱分析比较油茶籽油与橄榄油的甘油酯组成差异

Analysis and Comparison on Composition Differences of Glycerolipids in Camellia Oil and Olive Oil by Ultra Performance Liquid Chromatography-High Resolution Mass Spectrometry

采用基于超高效液相色谱-高分辨质谱(UPLC-HRMS)技术的脂质组学方法,分析比较了油茶籽油和橄榄油中的甘油酯组成,并总结了不同甘油酯的液相色谱保留行为。利用提取离子流图、母离子谱图和子离子质谱图,依据中性丢失质量计算甘油酯的脂肪酰基链组成。结果表明,油茶籽油和橄榄油中共检测到55种甘油酯,其中在油茶籽油中检测到全部55种甘油酯(43种甘油三酯和12种甘油二酯),橄榄油中检测到44种甘油酯(34种甘油三酯和10种甘油二酯),未检测到9种甘油三酯和2种甘油二酯。油茶籽油和橄榄油中最主要的甘油酯均为TAG 54∶3,但其相对含量在油茶籽油中更高。以55种甘油酯分子的峰面积作为变量进行多维变量统计分析,聚类热图分析、主成分分析和正交偏最小二乘法判别分析表明,油茶籽油和橄榄油具有显著的分类趋势。结合VIP值>1.0且p值<0.01筛选出油茶籽油的3种关键甘油酯和橄榄油的6种关键甘油酯。该研究揭示了油茶籽油与橄榄油中甘油酯的分子组成差异,可为解析油茶籽油的功能和营养提供基础。

The compositions of glycerolipids in camellia oil and olive oil were analyzed and compared using a lipidomics method based on ultra performance liquid chromatography-high resolution mass spectrometry(UPLC-HRMS).The retention behavior of different lipids by liquid chromatography was summarized.The main eluted components were diacylglycerols within 6.5-7.5 min,while within 10.6-12 min,the main eluted components were triacylglycerols.The base peak chromatogram showed that there were no significant differences in the retention time and abundance of glycerolipids between camellia oil and olive oil.The elution of glycerolipids by reversed-phase liquid chromatography was carried out according to the equivalent carbon number.The higher the equivalent carbon number,the longer the retention time.The structures of lipids were calculated according to the neutral lost mass by using the extracted ion chromatogram,primary mass spectrum and secondary mass spectrum.Results showed that 55 glycerolipids were detected in camellia oil and olive oil.All 55 glycerolipids,including 43 triacylglycerols and 12 diacylglycerols were detected in camellia oil.44 glycerolipids,including 34 triacylglycerols and 10 diacylglycerols were detected in olive oil,while 9 triacylglycerols and 2 diacylglycerols were not detected.TAG 54∶3 was the most important triacylglycerols in camellia oil and olive oil,but its relative content was higher in camellia oil.The relative contents of 9 triacylglycerols and 2 diacylglycerols detected in camellia oil but not in olive oil were all less than 1%.Camellia oil and olive oil have similar major glycerolipids,but they are quite different from other edible oils,such as soybean oil,rapeseed oil and sunflower oil.The peak areas of 55 glycerolipids species were used as the variable for multidimensional statistical analysis.The results of cluster heat map analysis,principal component analysis(PCA)and orthogonal partial least squares-discriminant analysis(OPLS-DA)showed that camellia oil and olive oil had a significant classification trend.Camellia oil and olive oil were aggregated into two different categories in the PCA score plot without any overlap.The contribution rate of the first principal component was 62.7%,while the contribution rate of the second principal component was 18.3%,indicating that there was significant difference in the glyceride abundance between camellia oil and olive oil.With VIP>1.0 and p<0.01,3 key glycerolipids were selected from camellia oil and 6 key glycerolipids were selected from olive oil.This study revealed the difference in the molecular composition of glycerolipids between camellia oil and olive oil,providing a basis for analyzing the function and nutrition of camellia oil.