Department Analytical Chemistry, Reference Materials, Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter-Str. 11, 12489 Berlin, Germany.
Molecular Phytopathology and Mycotoxin Research Section, University of Goettingen, Grisebachstrasse 6, 37077 Goettingen, Germany.
Molecules. 2019 Jul 24;24(15):2697. doi: 10.3390/molecules24152697.
Tempeh is a common food in Indonesia, produced by fungal fermentation of soybeans using , as well as , for inoculation. Analogously, for economic reasons, mixtures of maize and soybeans are used for the production of so-called tempeh-like products. For maize, a contamination with the mycoestrogen zearalenone (ZEN) has been frequently reported. ZEN is a mycotoxin which is known to be metabolized by and species. Consequently, this study focused on the ZEN transformation during tempeh fermentation. Five fungal strains of the genera and , isolated from fresh Indonesian tempeh and authentic Indonesian inocula, were utilized for tempeh manufacturing from a maize/soybean mixture (30:70) at laboratory-scale. Furthermore, comparable tempeh-like products obtained from Indonesian markets were analyzed. Results from the HPLC-MS/MS analyses show that ZEN is intensely transformed into its metabolites α-zearalenol (α-ZEL), ZEN-14-sulfate, α-ZEL-sulfate, ZEN-14-glucoside, and ZEN-16-glucoside in tempeh production. α-ZEL, being significantly more toxic than ZEN, was the main metabolite in most of the incubations, while in fermentations ZEN-14-sulfate was predominantly formed. Additionally, two of the 14 authentic samples were contaminated with ZEN, α-ZEL and ZEN-14-sulfate, and in two further samples, ZEN and α-ZEL, were determined. Consequently, tempeh fermentation of ZEN-contaminated maize/soybean mixture may lead to toxification of the food item by formation of the reductive ZEN metabolite, α-ZEL, under model as well as authentic conditions.
豆豉是印度尼西亚常见的一种食物，由真菌发酵大豆制成，接种物通常使用 和 。类似地，出于经济原因，也会使用玉米和大豆的混合物来生产所谓的类似豆豉的产品。玉米经常被报道受到真菌雌激素玉米赤霉烯酮（ZEN）的污染。ZEN 是一种真菌毒素，已知它可以被 和 种微生物代谢。因此，本研究专注于豆豉发酵过程中 ZEN 的转化。从新鲜的印度尼西亚豆豉和正宗的印度尼西亚接种物中分离出的五个属于 和 属的真菌菌株，用于在实验室规模上从玉米/大豆混合物（30:70）生产豆豉。此外，还分析了从印度尼西亚市场获得的类似豆豉产品。HPLC-MS/MS 分析结果表明，ZEN 在豆豉生产过程中会被强烈转化为其代谢物 α-玉米赤霉烯醇（α-ZEL）、ZEN-14-硫酸盐、α-ZEL-硫酸盐、ZEN-14-葡萄糖苷和 ZEN-16-葡萄糖苷。与 ZEN 相比，α-ZEL 的毒性更大，是大多数 菌株发酵中的主要代谢物，而在 菌株发酵中则主要形成 ZEN-14-硫酸盐。此外，14 个正宗样本中的两个样本受到 ZEN、α-ZEL 和 ZEN-14-硫酸盐的污染，在另外两个样本中则检测到 ZEN 和 α-ZEL。因此，在模型和真实条件下，ZEN 污染的玉米/大豆混合物的豆豉发酵可能会导致还原型 ZEN 代谢物 α-ZEL 的形成，从而使食品中毒化。
