Cis and trans components of lipids: Analysis by 1H NMR and silver shift reagents
Cis and trans components of lipids: Analysis by 1H NMR and silver shift reagents
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DOI：
10.1002/ejlt.201100348
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发表时间：
2012-05-01
影响因子：
2.7
通讯作者：
Dais, Photis
中科院分区：
文献类型：
--
作者：
Agiomyrgianaki, Alexia;Sedman, Jacqueline;Dais, Photis
本研究利用转移试剂方法来区分油脂中的顺式和反式不饱和度。银离子（以AgFOD的形式）与顺式和反式双键的差别结合允许在低频光谱仪（300？MHz）。在记录的定量1H NMR光谱中仔细积分适当的质子共振，得到与实际值非常一致的百分比浓度。通过分析AOCS实验室熟练程度计划GC样品，该1H NMR方法得到验证，该样品含有不同百分比的饱和、顺式单不饱和和顺式多不饱和脂肪以及反式含量。这种快速且相对低成本的NMR方法可用于在线获得含脂肪食品所需的营养标签成分数据（NLCD）。尝试区分具有不同程度的不饱和度和顺式双键的位置分布的脂质分子是不成功的。
In this study, the methodology of shift reagents was exploited to distinguish cis and trans unsaturation in oils and fats. The differential binding of silver ions (in the form of AgFOD) to cis and trans double bonds allowed the separation of the allylic and olefinic proton signals in the 1H NMR spectra of mixtures of cis and trans methyl esters of monoene aliphatic acids and unsaturated triacylglycerol mixtures at low frequency spectrometers (300?MHz). Careful integration of the appropriate proton resonances in the recorded quantitative 1H NMR spectra afforded percentage concentrations in very good agreement with the actual values. This 1H NMR methodology was validated by analyzing AOCS Laboratory Proficiency Program GC samples containing various percentages of saturated, cis-mono unsaturated, and cis-polyunsaturated fat as well as trans content. This fast and relatively low-cost NMR methodology could be used on line for obtaining nutrition labeling compositional data (NLCD) required for fat-containing food products. Attempts to differentiate lipid molecules with different degree of unsaturation and positional distribution of cis double bonds were unsuccessful.