Chair of Analytical Food Chemistry, Technical University of Munich, Freising, Germany.
ZIEL, Institute for Food & Health, Core Facility Human Studies, Technical University of Munich, Freising, Germany.
PLoS One. 2019 Feb 21;14(2):e0212255. doi: 10.1371/journal.pone.0212255. eCollection 2019.
Folates play a key role in the prevention of neural tube defects in newborns. Thus, it is important to reliably determine the bioavailability of folates from various foods. Accurate analytical methods are essential for quantifying blood-folates, especially in human studies. Here, we present the development and validation of a sensitive method using stable isotope dilution liquid chromatography coupled with mass spectrometry for determining various folates in plasma. Moreover, this study reports the applicability of the developed method to a human pilot study using strawberries as a test food. Validation of the assay revealed the precision, sensitivity, and accuracy of the method in determining the predominant 5-methyltetrahydrofolate in plasma. This method was also applicable for the screening of individual folate status using finger prick blood and for monitoring the post-absorptive plasma-concentration curve. Moreover, the human study revealed a high recovery of strawberry folates with a calculated relative bioavailability of 96.2%. Thus, the developed method enables prospective bioavailability studies. This work also confirmed, via human studies, that strawberries are a rich and natural source of folates that are available for human metabolism.
叶酸在预防新生儿神经管缺陷方面起着关键作用。因此，可靠地确定各种食物中叶酸的生物利用度非常重要。准确的分析方法对于定量检测血液中的叶酸至关重要，特别是在人体研究中。在这里，我们提出了一种使用稳定同位素稀释液相色谱-质谱联用技术测定血浆中各种叶酸的灵敏方法，并对其进行了开发和验证。此外，本研究还报告了该方法在以草莓作为测试食品的人体初步研究中的适用性。该方法在测定血浆中主要的 5-甲基四氢叶酸方面具有良好的精密度、灵敏度和准确度。该方法还可用于通过指尖采血筛查个体叶酸状态，并监测吸收后血浆浓度曲线。此外，人体研究表明草莓叶酸具有较高的回收率，计算得到的相对生物利用度为 96.2%。因此，该方法可用于前瞻性生物利用度研究。本研究还通过人体研究证实，草莓是一种富含天然叶酸的食物来源，可被人体代谢利用。
