植物油甘油三酯及其氧化聚合物分析方法研究
发布时间：2018-12-05 22:24
【摘要】：甘油三酯(TAGs)是天然油脂的主要成分,由于TAGs甘油骨架上结合的脂肪酸不同以及异构体的存在,TAGs种类非常庞大,开展TAGs分析方法研究,对监控食用油质量、保障食用油安全有重要意义。随着油脂加热时间的延长,油脂中极性组分(PC)含量增加,PC主要包括氧化甘油三酯寡聚物(TGO)、氧化甘油三酯二聚物(TGD)、氧化甘油三酯单体(ox-TG)、甘油二酯(DG)、游离脂肪酸(FFA)等,其中TGO和TGD统称为氧化甘油三酯聚合物(TGP)。TGP是油脂氧化过程中产生的一类复杂的深度氧化产物,其含量增加会对人体健康产生不利影响。TGP总量随着油脂氧化程度的加深而持续递增,是可以表征油脂氧化程度的内源性指标。本文研究了TAGs、TGP的分析方法。首先,探索了非水反相液相色谱分析植物油甘油三酯的条件,建立了非水反相高效液相色谱-质谱联用(NARP-HPLC-MS)分析方法,并采用该方法分析了17种植物油的甘油三酯组成及其相对含量。本研究中植物油色谱图含有的峰数量为9-22,其中棕榈酸型植物油的峰数量为8-10,亚麻酸型植物油的峰数量为13-22,亚油酸型植物油的峰数量为10-18,油酸型植物油的峰数量为8-11。植物油甘油三酯的当量碳数(ECN)范围为36-56,大部分植物油中当量碳数在42-48之间的TAG相对含量较多。棕榈酸型植物油的ECN范围为44-50,亚麻酸型植物油的ECN范围为36-50,其中月见草油还有极少量甘油三酯的ECN为52-56,亚油酸型植物油的ECN范围为38-52,油酸型植物油的ECN范围为44-52。根据不饱和程度将甘油三酯分类,各植物油中不同类型甘油三酯的含量有一些差异。甘油三酯是甘油与脂肪酸酯化的产物,脂肪酸根据不饱和度的多少分为饱和脂肪酸和不饱和脂肪酸,分别用“S”和“U”表示。棕榈酸类植物油中SSU和SUU型甘油三酯含量较高,共达到94.42%;检测的其他16种植物油均不饱和程度较高,SUU和UUU型甘油三酯总含量在88.73-99.17%之间。其次建立了非水反相液相色谱-银离子色谱离线二维液相色谱与质谱联用(Ag-HPLC-MS)的方法,并分析了葡萄籽油、月见草油和辣木籽油的甘油三酯位置异构体,及相同ECN值的甘油三酯。经Ag-HPLC-MS分析,辣木籽油、月见草油、葡萄籽油分别被鉴定出9、12和7组TAG位置异构体。结合一维NARPHPLC-MS的结果,辣木籽油共检测出22种甘油三酯及其异构体,月见草油共检测出37种甘油三酯及其异构体,葡萄籽油共有26种甘油三酯及其异构体被确认。然后研究了甘油三酯氧化聚合物的分析方法。首先建立了快速柱层析-高效体积排阻色谱对TGP的分析方法,对实验室自合成高纯度甘油三油酸酯(OOO)和甘油三亚油酸酯(LLL)加热产物进行了分析。通过对不同加热时间的OOO和LLL的氧化产物进行分析,其极性组分含量随着加热时间的延长均先迅速增加后增长速度变缓,其中由于亚油酸的不饱和程度更高,LLL极性组分含量增速更大。两种甘油三酯聚合物中TGO、TGD含量在加热初期均较低,在10%以下,ox-TG含量在40-50%之间。随加热时间的延长,TGO含量呈上升趋势,其中LLL加热体系中TGO在36-48h含量上升最快;TGD含量呈现先小幅度上升后平稳的趋势;ox-TG含量均先迅速下降,并在36h之后保持平缓。通过不同相对分子质量的聚苯乙烯标准物质绘制的标准工作曲线,计算得出TGO、TGD、ox-TG和DG的平均分子量分别为3215、1787、801和605。此方法操作简便、定量精确,定性准确。最后建立了快速柱层析-高效体积排阻色谱-质谱联用(PFC-HPSEC-MS)的方法,对TGP进行分析。通过质谱检测结果,可以看出OOO和LLL具有类似的氧化机理,经过加热氧化分别产生了单氢过氧化物、双氢过氧化物、单环氧化物和双环氧化物等氧化甘油三酯单体;OOO、LLL加热体系中的TGD分子量均较小于两倍ox-TG分子量,推测TGD由两种ox-TG缩合而成,且分子上有一条/两条脂肪酸链发生了裂解。
[Abstract]:Triglyceride (TAGs) is the main component of natural fat. Because of the different fatty acids and the presence of isomers, the TAGs are very large, and the TAGs analysis method is very important to monitor the quality of edible oil and to guarantee the safety of edible oil. As the heating time of the oil is prolonged, the content of the polar component (PC) in the oil is increased, and the PC mainly comprises an oxidized triglyceride oligomer (TGO), an oxidized triglyceride II (TGD), an oxidized triglyceride monomer (ox-TG), a diglyceride (DG), a free fatty acid (FFA), and the like, TGO and TGD are collectively referred to as the oxidized triglyceride polymer (TGP). TGP is a kind of complex deep oxidation product produced in the process of oil oxidation, and the increase in the content of TGP can have a negative effect on the health of human body. The total amount of TGP continues to increase with the deepening of the degree of oil oxidation, which is an endogenous indicator that can be used to characterize the degree of oil oxidation. The analytical methods of TAGs and TGP are studied in this paper. Firstly, the conditions of non-aqueous anti-phase liquid chromatography for the analysis of vegetable oil triglyceride were explored, and a non-aqueous anti-phase high performance liquid chromatography-mass spectrometry (NARP-HPLC-MS) analysis method was established, and the composition and relative contents of the triglyceride of 17 vegetable oils were analyzed by this method. The peak number of the vegetable oil chromatogram in the study is 9-22, wherein the peak quantity of the palmitic acid type vegetable oil is 8-10, the peak quantity of the linolenic acid type vegetable oil is 13-22, the peak quantity of the linoleic acid type vegetable oil is 10-18, and the peak quantity of the oleic acid type vegetable oil is 8-11. The equivalent carbon number (ECN) range of the vegetable oil triglyceride is 36-56, and the relative content of the equivalent carbon number between 42 and 48 in most of the vegetable oil is more. The ECN range of the palmitic acid type vegetable oil is 44-50, the ECN range of the linolenic acid type vegetable oil is 36-50, the ECN range of the monthly primrose oil and the small amount of triglyceride is 52-56, the ECN range of the linoleic acid type vegetable oil is 38-52, and the ECN range of the oleic acid type vegetable oil is 44-52. Triglycerides were classified according to the degree of unsaturation, and there were some differences in the contents of the different types of triglycerides in the various vegetable oils. Triglyceride is the product of the esterification of glycerol and fatty acid, and the fatty acid is divided into saturated fatty acid and unsaturated fatty acid according to the degree of unsaturation, and is represented by 鈥淪鈥，
本文编号：2365533
[Abstract]:Triglyceride (TAGs) is the main component of natural fat. Because of the different fatty acids and the presence of isomers, the TAGs are very large, and the TAGs analysis method is very important to monitor the quality of edible oil and to guarantee the safety of edible oil. As the heating time of the oil is prolonged, the content of the polar component (PC) in the oil is increased, and the PC mainly comprises an oxidized triglyceride oligomer (TGO), an oxidized triglyceride II (TGD), an oxidized triglyceride monomer (ox-TG), a diglyceride (DG), a free fatty acid (FFA), and the like, TGO and TGD are collectively referred to as the oxidized triglyceride polymer (TGP). TGP is a kind of complex deep oxidation product produced in the process of oil oxidation, and the increase in the content of TGP can have a negative effect on the health of human body. The total amount of TGP continues to increase with the deepening of the degree of oil oxidation, which is an endogenous indicator that can be used to characterize the degree of oil oxidation. The analytical methods of TAGs and TGP are studied in this paper. Firstly, the conditions of non-aqueous anti-phase liquid chromatography for the analysis of vegetable oil triglyceride were explored, and a non-aqueous anti-phase high performance liquid chromatography-mass spectrometry (NARP-HPLC-MS) analysis method was established, and the composition and relative contents of the triglyceride of 17 vegetable oils were analyzed by this method. The peak number of the vegetable oil chromatogram in the study is 9-22, wherein the peak quantity of the palmitic acid type vegetable oil is 8-10, the peak quantity of the linolenic acid type vegetable oil is 13-22, the peak quantity of the linoleic acid type vegetable oil is 10-18, and the peak quantity of the oleic acid type vegetable oil is 8-11. The equivalent carbon number (ECN) range of the vegetable oil triglyceride is 36-56, and the relative content of the equivalent carbon number between 42 and 48 in most of the vegetable oil is more. The ECN range of the palmitic acid type vegetable oil is 44-50, the ECN range of the linolenic acid type vegetable oil is 36-50, the ECN range of the monthly primrose oil and the small amount of triglyceride is 52-56, the ECN range of the linoleic acid type vegetable oil is 38-52, and the ECN range of the oleic acid type vegetable oil is 44-52. Triglycerides were classified according to the degree of unsaturation, and there were some differences in the contents of the different types of triglycerides in the various vegetable oils. Triglyceride is the product of the esterification of glycerol and fatty acid, and the fatty acid is divided into saturated fatty acid and unsaturated fatty acid according to the degree of unsaturation, and is represented by 鈥淪鈥，
本文编号：2365533
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