蔬菜脂肪和油 用毛细管气相色谱法测定三酰基甘油的组成及二酰基甘油的组成和含量

[中文适用范围]： 本文件规定了采用毛细管气相色谱法测定月桂酸含量低于1%的植物油中三酰基甘油的组成以及二酰基甘油的组成和含量的方法。 在特定的技术加工过程中，1,2-二酰基甘油（1,2-DAGs）会通过酸催化反应转化为更稳定的异构体1,3-二酰基甘油（1,3-DAGs）。在储存期间，这种重排的速度和程度取决于油的酸度。转化通常在两种异构体形式之间达到平衡。1,2-DAGs的相对含量与油的新鲜度或可能的技术处理有关。因此，可以使用1,2-DAGs与1,3-DAGs的比率作为植物油脂的质量标准。 三酰基甘油的谱图对每种植物油的指纹特征具有潜在意义，并可能有助于检测某些类型的掺假，例如在橄榄油中添加高油酸葵花籽油或棕榈油精。 注：本文件基于参考文献[3]。 [外文原描述]： This document specifies the determination of composition of triacylglycerols and the determination of the composition and content of diacylglycerols by capillary gas chromatography in vegetable oils with a lauric acid content below 1 %. Applying certain technological processing 1,2-diacylglycerols (1,2-DAGs) are transformed to the more stable isomeric 1,3-diacylglycerols (1,3-DAGs) due to acidic catalysed reaction. During storage, the speed and amount of this rearrangement depends on the acidity of the oil. The transformation normally reaches an equilibrium between the two isomeric forms. The relative amount of 1,2-DAGs is related to oil freshness or to a possible technological treatment. Therefore, it is possible to use the ratio of 1,2-DAGs to 1,3-DAGs as a quality criterion for vegetable fats and oils. The triacylglycerols profile is of potential interest for the fingerprint of each vegetable oil and may help the detection of certain types of adulteration, such as the addition of high oleic sunflower oil or palm olein in olive oil. NOTE This document is based on Reference [ 3 ].