Occurrence and thermal stability of the mycotoxin citrinin

霉菌毒素柑橘素的存在和热稳定性

• 批准号: 465450389
• 负责人: Professor Dr. Hans-Ulrich Humpf
• 金额: --
• 依托单位: Institut für Lebensmittelchemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/465450389?language=en
• 关键词: Occurrence; thermal; stability; mycotoxin; citrinin

Citrinin is a mycotoxin produced by Aspergillus, Penicillium and Monascus species found predominantly in the lower µg/kg range in cereals and in much lower concentrations in processed cereal samples. This difference clearly demonstrates that food processing has a strong impact on citrinin levels. Furthermore, recent human biomonitoring data show that citrinin is detectable in the majority of the analyzed European urine samples in the lower ng/mL range. The human biomonitoring data and the discrepancy between citrinin levels in raw material and processed cereals clearly demonstrate that there is a gap between exposure calculated from food intake and occurrence data. It has been shown that citrinin is a reactive mycotoxin which can be converted to degradation products when heated in pure solutions or as solid. However, studies describing thermal reactions of citrinin in the presence of realistic food matrices as well as the potential binding of citrinin to matrix-components have not been performed yet and are the subject of this proposal. Using model compounds mimicking food constituents such as carbohydrates, reducing sugars and proteins the formation of degradation and reaction products of citrinin will be investigated. In a second step, the thermal degradation of citrinin in complex matrices will be studied during classical thermal processing such as baking and extrusion cooking. The identification of degradation products will be first performed based on HPLC-HRMS followed by isolation and NMR-based structure elucidation. For the detection of matrix-bound forms of citrinin, samples obtained from baking and extrusion cooking with high reduction rates of citrinin will be enzymatically or chemically hydrolyzed and analyzed for monomers of matrix-bound forms of citrinin. Furthermore, the release (and metabolism) of matrix-bound forms of citrinin in the gastrointestinal tract will be studied using the pig cecum model. The cytotoxicity of formed degradation products will be investigated in cell culture experiments. Finally, citrinin, potential thermal degradation products as well as matrix-bound forms of citrinin will be quantified in commercially available food samples in order to estimate the relevance for human exposure.

柑橘霉素是一种霉菌毒素，由曲霉、青霉菌和红曲霉产生，在谷物中含量较低，在加工过的谷物样品中含量较低。这种差异清楚地表明，食品加工对黄朊蛋白水平有很大的影响。此外，最近的人类生物监测数据显示，在大多数分析的欧洲尿液样本中，柠檬酸钠在较低的ng/mL范围内可检测到。人体生物监测数据以及原料和加工谷物中柑橘霉素水平之间的差异清楚地表明，从食物摄入量计算出的暴露量与发生数据之间存在差距。研究表明，柑桔毒素是一种反应性真菌毒素，在纯溶液或固体加热时可转化为降解产物。然而，描述柑橘霉素在现实食物基质中存在的热反应以及柑橘霉素与基质成分的潜在结合的研究尚未进行，这是本提案的主题。利用模拟食物成分的模型化合物，如碳水化合物、还原糖和蛋白质，将研究柠檬黄蛋白的降解和反应产物的形成。在第二步中，将研究在经典的热加工过程中，如烘烤和挤压蒸煮，柑桔素在复杂基质中的热降解。降解产物的鉴定将首先基于HPLC-HRMS进行，然后是基于分离和核磁共振的结构解析。为了检测基质结合形式的柑桔霉素，通过烘烤和挤压蒸煮获得的样品具有很高的柑桔霉素还原率，将被酶或化学水解并分析基质结合形式的柑桔霉素单体。此外，将使用猪盲肠模型研究基质结合形式的柑橘霉素在胃肠道中的释放（和代谢）。形成的降解产物的细胞毒性将在细胞培养实验中进行研究。最后，将对市售食品样品中的柑橘霉素、潜在的热降解产物以及基质结合形式的柑橘霉素进行量化，以估计其与人类暴露的相关性。