食品中隐蔽型伏马菌素的发现及其膳食暴露风险研究

Fumonisins are widespread found in grains and their processed products, which could cause various carcinogenic diseases in humans. Conventional targeted analytical methods are commonly effective for detection of fumonisins, but not for their modified forms. Lack of a reliable analytical method leads to significant underestimation of the exposure risk of modified fumonisins. This food safety issue attracts strong attentions global wise. Combining advanced analytical chemistry and dietary exposure assessment, this project aims to discover modified fumonisins and assess their dietary exposure risk. Discovery of unknown toxins involves the core technology of non-targeted screening based on high-resolution mass spectroscopy. Following structure elucidation, the typical modified fumonisins could be synthesized to enable the establishment of an ultra-sensitive and multi-target quantification by LC-MS/MS. The project will analyze the migration and transformation of modified fumonisins caused by cooking through the raw-cooked paired sampling of China total diet study. This is the first time for modified fumonisins to be included in risk assessment for exposure to fumonisins. The project will further establish a principal database of modifed fumonisins in Chinese residential diet. As another outcome, dietary exposure risk will also be analyzed. Eventually, the project will provide technical support to setting combined maximum levels of fumonisins and modified fumonisins.

伏马菌素在粮食及其制品中广泛存在，与多种人类癌症相关，其隐蔽型通过传统靶向检测方法难以被发现，导致隐蔽型伏马菌素暴露风险被严重低估，引起国内外高度关注。本项目以隐蔽型伏马菌素为研究对象，结合分析化学与暴露评估手段，实现隐蔽型伏马菌素的发现与风险评估。本项目利用高分辨质谱非靶向筛查策略，发现未知毒素并解析结构，合成典型隐蔽型毒素，实现伏马菌素及其隐蔽型的痕量多组分定量分析，构建未知毒素筛查发现、结构解析、合成制备、精准定量分析平台。借助中国总膳食研究，收集生熟配对样品，分析隐蔽型伏马菌素在食物烹调过程中的迁移转化规律。首次将隐蔽型纳入伏马菌素暴露评估体系，创建我国居民膳食中隐蔽型伏马菌素污染基础数据库，分析膳食暴露风险及主要贡献。为伏马菌素及其隐蔽型联合限量标准的制定提供技术支持。

伏马菌素在粮食及其制品中广泛存在，与多种人类癌症相关，其隐蔽型通过传统检测方法难以被发现，导致隐蔽型伏马菌素暴露风险被严重低估，引起国内外高度关注。本课题以隐蔽型伏马菌素为研究对象，结合分析化学与暴露评估手段，实现隐蔽型伏马菌素的定量与暴露风险评估。本项目利用高分辨质谱对污染粮食的分析，发现伏马菌素类似物的结构骨架碎片离子，合成典型隐蔽型伏马菌素，并进行结构表征。进而建立准确、灵敏的谷物和膳食样品中伏马菌素及其隐蔽型的同位素稀释LC-MS/MS检测方法，克服了水解型伏马菌素及其同位素标准品无法商业化获得的瓶颈。本课题在我国24个省（直辖市和自治区）进行膳食样品采样和消费量调查，对样品进行含量分析，我国伏马菌素（FB1+FB2+FB3）及其隐蔽型的总量平均水平为7.95 ng/g，其中隐蔽型伏马菌素占27.6%。以FB1及其隐蔽型的总量最高，FB2次之，FB3最低，其比列约为6:3:1。本课题首次将隐蔽型纳入伏马菌素暴露评估体系，分析膳食暴露风险及主要贡献。从全国总体来看，我国原型伏马菌素暴露量为65.80 ng/kg bw/day，约为JECFA制定的PMTDI（2µg/kg bw/day）的3.29%；而伏马菌素总暴露量为93.64 ng/kg bw/day，约为JECFA制定的PMTDI的4.68%，其中约30%的暴露量为隐蔽型伏马菌素所贡献。不同地区暴露差异较大，北方地区隐蔽型伏马菌素对暴露量的贡献比（28.9%）较南方地区（8.67%）高，这表明由于南北方膳食种类的差异以及气候差异使隐蔽型伏马菌素的暴露贡献产生差异。FB1及其隐蔽型仍是暴露的主要来源，而FB2和FB3的贡献也不可忽视。因此，虽然总体上我国伏马菌素暴露健康风险较低，但若忽略隐蔽型伏马菌素的贡献会造成暴露风险被低估，需要将隐蔽型伏马菌素纳入食品污染监测和暴露评估之中。