Wroclaw University of Science and Technology, Faculty of Chemistry, Department of Analytical Chemistry and Chemical Metallurgy, Wybrzeze St. Wyspianskiego 27, 50-370, Wroclaw, Poland.
Wroclaw University of Science and Technology, Faculty of Chemistry, Department of Analytical Chemistry and Chemical Metallurgy, Wybrzeze St. Wyspianskiego 27, 50-370, Wroclaw, Poland.
J Trace Elem Med Biol. 2020 Jul;60:126479. doi: 10.1016/j.jtemb.2020.126479. Epub 2020 Feb 28.
Bee pollen is recognized to be a source of different nutrients, including minerals. As a food supplement, its quality and safety due to concentrations of essential macro- and microelements, and harmful trace elements has to be verified. Fast and simple element analysis of bee-collected pollen can be regarded as an important part of its quality assurance and control. The present study aimed at developping a new method for determination of selected elements (Ca, Cu, Fe, Mg, Mn, Zn) of bee pollen based on solvent extraction and completely avoiding a high temperature treatment with concentrated reagents. In addition, in vitro gastrointestinal digestion was used to assess bioavailability of elements from this food supplement.
Bee pollen samples were dried and pulverized. Total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn were determined by flame atomic absorption spectrometry (FAAS) in sample solutions obtained by wet digestion (WD) in concentrated HNO or alternatively by solvent extraction (SE) with diluted solutions of HNO. Gastrointestinal digestion was mimicked using simulated solutions of gastric and intestinal juices followed by determination of Ca, Cu, Fe, Mg, Mn and Zn concentrations in the bioaccessible fraction by FAAS.
A new simple and fast method for determination of total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen was developed and validated. The method combined room temperature, two-hour SE with 0.5 mol L HNO with FAAS measurements versus simple standard solutions. It provided precision within 1-5 % and trueness better than 8%, and was shown to be suitable for fast analysis of different polyfloral bee pollens. In vitro gastrointestinal digestion revealed that elements were well (70-85 % for Ca, Mg) and fairly (27-43 % for Cu, Fe, Mn, and Zn) bioaccessible from bee pollen. By pouring with water and swelling overnight, bioaccessibility of studied elements from such prepared bee pollen was increased on average by less than 15 % (Mn), 20 % (Ca, Cu, Fe, Zn) or 30 % (Mn).
Avoiding long-lasting, high-temperature wet digestion with concentrated reagents, the proposed sample treatment along with FAAS provided precise and true results of total concentrations of Ca, Cu, Fe, Mg, Mn, and Zn in bee pollen. The method was simple and fast, and enabled to analyze a higher number of samples. Simulated gastrointestinal digestion of bee pollen have shown for the first time that Ca and Mg are the most bioaccessible from this bee product. Bioaccessibility of Cu, Fe, Mg, and Zn from bee pollen are close to or lower than 40 %.
蜂花粉被认为是多种营养物质的来源，包括矿物质。作为一种食品补充剂，其质量和安全性因其必需的宏量和微量元素以及有害痕量元素的浓度而必须得到验证。对蜜蜂采集的花粉进行快速简单的元素分析可以被视为其质量保证和控制的重要组成部分。本研究旨在开发一种新的方法，用于基于溶剂萃取完全避免使用浓试剂进行高温处理的情况下，测定蜂花粉中选定元素（Ca、Cu、Fe、Mg、Mn、Zn）的含量。此外，还使用体外胃肠道消化来评估这种食品补充剂中元素的生物利用度。
将蜂花粉样品干燥并粉碎。通过火焰原子吸收光谱法（FAAS）在经浓 HNO3湿法消解（WD）或用稀 HNO3溶液进行溶剂萃取（SE）获得的样品溶液中测定 Ca、Cu、Fe、Mg、Mn 和 Zn 的总浓度。使用模拟胃液和肠液进行胃肠道消化，然后通过 FAAS 测定生物可利用部分的 Ca、Cu、Fe、Mg、Mn 和 Zn 浓度。
开发并验证了一种新的简单快速测定蜂花粉中 Ca、Cu、Fe、Mg、Mn 和 Zn 总量的方法。该方法将室温下两小时 SE 与 0.5 mol L HNO3结合使用，与 FAAS 测量相结合，适用于快速分析不同的多花蜂花粉。体外胃肠道消化表明，元素的生物利用度较高（Ca、Mg 为 70-85%），而生物利用度中等（Cu、Fe、Mn 和 Zn 为 27-43%）。通过用水浇和过夜膨胀，用这种方法制备的蜂花粉中研究元素的生物利用度平均增加了不到 15%（Mn）、20%（Ca、Cu、Fe、Zn）或 30%（Mn）。
避免使用浓试剂进行长时间高温湿法消解，该方法与 FAAS 一起提供了蜂花粉中 Ca、Cu、Fe、Mg、Mn 和 Zn 总量的精确和真实结果。该方法简单快速，可分析更多数量的样品。对蜂花粉的模拟胃肠道消化首次表明，Ca 和 Mg 是这种蜂产品中最易生物利用的元素。蜂花粉中 Cu、Fe、Mg 和 Zn 的生物利用度接近或低于 40%。
