Environmental Geochemistry, Bayreuth Center for Ecology and Environmental Research (BAYCEER), University of Bayreuth, 95440 Bayreuth, Germany.
Food Chem. 2024 Mar 15;436:137723. doi: 10.1016/j.foodchem.2023.137723. Epub 2023 Oct 13.
Thioarsenates have recently been detected in rice and rice-based products, with particularly high contents in puffed rice cakes. Here, we show that puffing rice can cause almost complete transformation of dimethylarsenate (DMA) to dimethyldithioarsenate (DMDTA) and dimethylmonothioarsenate (DMMTA). Analysis of puffed rice cakes after 3 months of non-sealed storage at room temperature showed transformation of DMDTA mainly into DMMTA. From a food safety perspective, this likely represents an increased risk because DMMTA is highly cytotoxic and misidentified as non-regulated DMA by routine acid extractions. Analysis of 80 commercial puffed rice cakes confirmed widespread occurrence of thioarsenates. The sum of non-regulated, but potentially toxic DMMTA and DMDTA reached values up to 537 µg·kg and 241 µg·kg for generic and infant-labeled rice cakes, respectively. Our results highlight the importance of better understanding (de)thiolation processes along the rice cake-production chain and potentially revising current thresholds set for iAs to include DMMTA and DMDTA.
硫代砷酸盐最近在大米及其制品中被检测到，其中膨化米糕中的含量特别高。在这里，我们表明膨化米可以导致二甲砷酸（DMA）几乎完全转化为二甲基二硫代砷酸（DMDTA）和二甲基单硫代砷酸（DMMTA）。分析在室温下非密封储存 3 个月后的膨化米糕表明，DMDTA 主要转化为 DMMTA。从食品安全的角度来看，这可能代表着风险的增加，因为 DMMTA 具有高度细胞毒性，并且会被常规酸提取错误地识别为非监管的 DMA。对 80 个商业膨化米糕的分析证实了硫代砷酸盐的广泛存在。非监管但潜在有毒的 DMMTA 和 DMDTA 的总和分别达到普通和婴儿标签米糕的 537µg·kg 和 241µg·kg。我们的研究结果强调了更好地理解（脱）巯基化过程沿着米糕生产链的重要性，并可能需要修订目前为 iAs 设定的阈值，以包括 DMMTA 和 DMDTA。
