Mineral oil hydrocarbons in foods: is the data reliable ?

The contamination of foods with mineral oil hydrocarbons (MOH) is a serious concern, requiring in most cases tedious mitigation measures that span across the whole food supply chain. A major issue today is the significant variability of the results generated by laboratories. This study was therefore designed to achieve a deeper insight into the analytical procedures used by commercial laboratories, identifying possible gaps and suggesting improvements that will enhance the reliability of the MOH data, an important prerequisite for risk assessment. In total six different food matrices, i.e. infant formula (IF), cocoa butter, cocoa powder, biscuits, fruit-based baby food containing biscuit and roast and ground coffee were subjected to comparative inter-laboratory studies, as well as one vegetable oil analysed within the frame of a professionally conducted proficiency test. The results indicate that on some matrices with possibly low amounts of MOH contamination, the current methodologies cannot reliably conclude whether or not a food sample is indeed contaminated with mineral oils (<10 mg/kg food). Urgently needed are: (i) an aligned and fully validated sample preparation strategy tested on a range of different food matrices; (ii) a confirmation of positive flame ionisation detection (FID) results by confirmatory methods such as mass spectrometry – in line with the CEN Standard and the Joint Research Centre (JRC) Guidance Document, (iii) a more detailed root-cause analysis in the reports of laboratories through the use of mineral oil markers, and (iv) a fully validated official method for the concerned foods with a limit of application <10 mg/kg food.

食品受到矿物油烃类（mineral oil hydrocarbons, MOH）污染是一项备受关注的严峻问题，多数情况下需在整条食品供应链中落实繁琐的防控举措。当前一项突出的核心问题是，不同实验室出具的检测结果存在显著差异。因此本研究旨在深入解析商业实验室所采用的分析流程，识别其中潜在的不足，并提出改进建议，以提升矿物油烃类检测数据的可靠性——这是开展风险评估的重要前提。本研究共纳入6种不同食品基质，即婴儿配方食品（infant formula, IF）、可可脂、可可粉、饼干、含饼干的果泥类婴幼儿食品以及烘焙研磨咖啡，开展实验室间比对试验；另有1份植物油在专业组织的能力验证框架下完成分析。结果表明，针对部分矿物油烃类污染负荷较低的食品基质，当前的检测方法无法可靠判定食品样品是否确受矿物油污染（<10 mg/kg食品）。当前亟需推进以下工作：(i) 制定统一且经全面验证的样品前处理策略，并在多类食品基质中完成验证测试；(ii) 遵循欧洲标准化委员会（CEN）标准及欧盟联合研究中心（Joint Research Centre, JRC）指导文件，采用质谱法等确证手段，对火焰离子化检测器（flame ionisation detection, FID）的阳性检测结果进行复核确证；(iii) 依托矿物油标志物，在实验室报告中开展更细致的根本原因溯源分析；(iv) 针对目标食品建立经全面验证的官方检测方法，其应用限值需低于10 mg/kg食品。