Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, IRD, Univ. G. Eiffel, ISTerre, Grenoble, France.
Escuela Superior Politécnica del Litoral, ESPOL, Facultad de Ciencias de la Vida, Campus Gustavo Galindo Km. 30.5 Vía Perimetral, P.O. Box 09-01-5863, Guayaquil, Ecuador.
Food Chem. 2024 Jan 15;431:137068. doi: 10.1016/j.foodchem.2023.137068. Epub 2023 Aug 8.
Cadmium (Cd) concentrations in cacao often exceed food limits. Recently, it was shown that cacao bean fermentation enhances Cd solubility, opening potential for Cd mitigation in cacao products. This study was set-up to identify changes in Cd speciation during fermentation. X-Ray absorption spectroscopy (XAS) complemented with speciation calculations, were used on samples collected from high and low Cd farms, that were subjected to a fermentation-like incubation that reached high temperatures (>45 °C) and acidic pH (<5). Incubation decreased nib Cd concentration up to a factor 1.5 and changed Cd complexation in high Cd beans from sulphur to oxygen ligands, likely due to pH changes. In beans with lower Cd concentrations, Cd was complexed before and after incubation with oxygen-ligands. A combination of pH changes and/or phytate breakdown may explain the migration of Cd outward from the nib. XAS and speciation calculations proved complimentary techniques and indicated similar speciation changes during fermentation.
可可豆中的镉 (Cd) 浓度常常超过食品限量。最近的研究表明，可可豆发酵可以提高 Cd 的溶解度，为降低可可产品中的 Cd 提供了可能。本研究旨在确定发酵过程中 Cd 形态的变化。使用 X 射线吸收光谱 (XAS) 结合形态计算，对来自高 Cd 和低 Cd 农场的样品进行了分析，这些样品经历了类似于发酵的孵育过程，达到了高温 (>45°C) 和酸性 pH(<5)。孵育使 nib 中的 Cd 浓度降低了 1.5 倍，并改变了高 Cd 豆中 Cd 的配位体从硫变成了氧，这可能是由于 pH 值的变化。在 Cd 浓度较低的豆中，Cd 在孵育前后都与氧配位体结合。pH 值变化和/或植酸盐分解的结合可能解释了 Cd 从 nib 向外迁移的现象。XAS 和形态计算证明是互补的技术，并表明发酵过程中 Cd 形态发生了相似的变化。
