Structure elucidation of transformation products of toxic plant alkaloids in stored or processed foods

该研究项目旨在阐明食品污染物吡咯里西丁生物碱(PA)、托烷生物碱(TA)和秋水仙碱(Col)的潜在转化产物。这些有毒植物的产品在储存或进一步加工受污染的食品或原材料时可能会产生生物碱。本项目重点研究了蜂蜜、面包、牛奶或酸奶中有毒生物碱PA、TA和COL在储存、烘焙和微生物发酵过程中的影响。具体而言，该项目旨在研究蜂蜜储存对PA-N-氧化物的影响、面包烘焙对TA的影响以及酸奶发酵对PA和COL的影响。为此，必须建立所需的分析方法，并从上述食物基质中提取人工污染的样品。在蜂蜜储存期间或在烘焙面包和将牛奶发酵成酸奶的过程中，会定期检测PA、TA和Col的含量。在预期PA、TA和COL初始含量下降的情况下，通过对天然物质样品和产品样品的非靶向性分析，结合多元数据分析，确定有毒生物碱的潜在转化产物。通过改变工艺参数来确定对天然生物碱化合物的降解以及转化产物的形成的影响。最后，根据所获得的数据，推测了PA、TA和COL转化产物的可能形成途径。

The research project aims to elucidate potential transformation products of the food contaminats pyrrolizidine alkaloids (PA), tropane alkaloids (TA) and colchicine (COL). Products of these toxic plants alkaloids can arise during the storage or further processing of contaminated food or raw materials. Herein, the project focuses on the effects of storage, thermal processing (baking) and microbial fermentation on the toxic alkaloids PA, TA and COL in the relevant food matrices honey, bread and milk or yoghurt, respectively. In detail, the project aims to examine the effects of honey storing on PA-N-oxides, baking of bread on TA and fermentation of yogurt on PA and COL.For this, the required analytical methods have to be established, and artificially contaminated samples from the above mentiones food matrices have to be produced. The PA, TA and COL contents are examined at regular intervals during the storage of honey or during the process of baking bread and fermenting milk into yoghurt. In case of the expected decrease of the initial contents of PA, TA and COL, potential transformation products of the toxic alkaloids are identified by untargeted analysis of the native material samples and product samples, using high-resolution mass spectrometry (LC QToF-HRMS) combined with multivariate data analysis. Effects on the degradation of the native alkaloid compounds as well as the formation of transformation products are determined via a variation of process parameters. Finally, possible formation pathways of identified transformation products from PA, TA and COL are postulated with the obtained data .