Department of Bioanalytical Science, Nestle Research Centre, Lausanne, Switzerland.
J Agric Food Chem. 2010 Feb 24;58(4):2055-61. doi: 10.1021/jf903930k.
Betaine and choline are important components of the one-carbon metabolism cycle, linked with the amino acid homocysteine and lipid metabolism. Analyses of broad ranges of foods point to cereal based foods being important sources of betaine and choline, however to date there has been no detailed analysis of these compounds in cereal flours or cereal products. An analytical method based on optimization of an existing extraction followed by LC-MS/MS analysis was used to analyze 47 plasma samples, 32 cereal flours and cereal fractions, and 51 cereal products. For the method validation LLOQ, recovery, inter- and intraday repeatability were all performed. Whole-grain wheat and rye flours, and products based on these were the best whole cereal sources of betaine (747-1508 microg/g) and to a lesser extent choline (76-159 microg/g), while the bran fraction contained the highest concentrations of betaine and free-choline (2350-2899 microg/g and 366-384 microg/g respectively). Refined wheat flour and products contained lower concentrations, while rice and maize contained only very low and no detectable amounts of betaine respectively (0-10 microg/g), and low amounts of free-choline (<31 microg/g). These results were mirrored in cereal products analyzed, with whole-grain wheat or rye-based cereal products having the highest concentrations of the two metabolites. Plasma concentrations for betaine and free-choline in a group of 47 subjects ranged from 15.2-66.3 and 9.8-18.5 micromol/L respectively, within the range of previous reports. This LC-MS/MS method can be used to rapidly and sensitively quantify betaine and free-choline in plasma and cereal products. Whole-grain cereal products and products containing cereal bran appear to be excellent dietary sources of betaine and free-choline.
甜菜碱和胆碱是一碳代谢循环的重要组成部分，与氨基酸同型半胱氨酸和脂质代谢有关。对各种食物的分析表明，以谷物为基础的食物是甜菜碱和胆碱的重要来源，但迄今为止，还没有对谷物面粉或谷物产品中这些化合物进行详细分析。本研究采用一种基于优化现有提取方法的 LC-MS/MS 分析方法，分析了 47 份血浆样本、32 份谷物面粉和谷物成分以及 51 种谷物产品。对该方法进行了验证，包括LLOQ、回收率、日内和日间重复性。全谷物小麦和黑麦面粉及其制成品是甜菜碱（747-1508μg/g）和胆碱（76-159μg/g）的最佳全谷物来源，而麸皮部分含有最高浓度的甜菜碱和游离胆碱（分别为 2350-2899μg/g 和 366-384μg/g）。精制小麦面粉及其制成品的浓度较低，而大米和玉米则分别只含有非常低或无法检测到的甜菜碱（0-10μg/g）和低浓度的游离胆碱（<31μg/g）。这些结果在分析的谷物产品中得到了反映，以全谷物小麦或黑麦为基础的谷物产品含有这两种代谢物的最高浓度。47 名受试者的血浆甜菜碱和游离胆碱浓度范围分别为 15.2-66.3μmol/L 和 9.8-18.5μmol/L，处于之前报道的范围内。该 LC-MS/MS 方法可用于快速灵敏地定量血浆和谷物产品中的甜菜碱和游离胆碱。全谷物谷物产品和含有谷物麸皮的产品似乎是甜菜碱和游离胆碱的极好膳食来源。
