a Food Research Division, Bureau of Chemical Safety, Food Directorate-HPFB , Health Canada , Ottawa , Ontario , Canada.
b Analytical Laboratory , CER Groupe , Marloie , Belgium.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2019 Feb;36(2):327-335. doi: 10.1080/19440049.2019.1567943. Epub 2019 Jan 29.
Sterigmatocystin (STC) is a toxic secondary metabolite produced by more than 50 fungal species, including Aspergillus flavus, A. parasiticus, A. nidulans, and A. versicolor. The Joint FAO/WHO Expert Committee on Food Additives concluded that sterigmatocystin is genotoxic and carcinogenic with the critical effect determined to be carcinogenicity. The present study describes a simple method to prepare hapten and immunogens in order to generate polyclonal antibodies against this metabolite. We developed a sensitive and specific polyclonal antibody-based competitive indirect enzyme-linked immunosorbent assay (ciELISA) for monitoring STC in wheat and corn flours without the need for derivatisation of STC or clean-up of samples by immunoaffinity chromatography for quantification. The half inhibitory concentration (IC) of the established method was 4.52 ± 0.81 ng mL, with the limit of detection (IC) being 0.19 ± 0.04 ng mL in wheat and corn flour matrices with the coefficient of variation of less than 22%.The assay was very specific to STC and showed no cross-reactivity with its analogue structures. The ELISA allowed for up to 5% methanol without significant influence on the IC value. Validation of the assay was performed by spiking STC into a blank flour matrix and the recoveries were in the range of 75.3 % to 104.5 % with a coefficient of variation less than 15%. A small retail survey was conducted by purchasing wheat (n = 8) and corn flours (n = 2) from local grocery stores. All of these retail samples were negative for STC using the developed ELISA method and were confirmed by LC-MS/MS. We demonstrated a rapid, simple, and reliable method for screening STC in wheat and corn flours.
赭曲霉素（STC）是一种由超过 50 种真菌物种产生的有毒次级代谢物，包括黄曲霉、寄生曲霉、构巢曲霉和杂色曲霉。粮农组织/世卫组织食品添加剂联合专家委员会得出结论，赭曲霉素具有遗传毒性和致癌性，其关键效应被确定为致癌性。本研究描述了一种简单的方法来制备半抗原和免疫原，以便针对这种代谢物产生多克隆抗体。我们开发了一种基于敏感和特异性多克隆抗体的竞争性间接酶联免疫吸附测定（ciELISA），用于监测小麦和玉米粉中的 STC，而无需对 STC 进行衍生化或通过免疫亲和色谱对样品进行净化以进行定量。所建立方法的半抑制浓度（IC）为 4.52 ± 0.81 ng mL，检测限（IC）为 0.19 ± 0.04 ng mL，在小麦和玉米粉基质中的变异系数小于 22%。该测定法对 STC 具有很高的特异性，与类似结构无交叉反应。该 ELISA 允许添加高达 5%的甲醇，而对 IC 值没有显著影响。通过向空白面粉基质中添加 STC 来验证该测定法，回收率在 75.3%至 104.5%之间，变异系数小于 15%。通过从当地杂货店购买小麦（n = 8）和玉米粉（n = 2）进行了一项小型零售调查。使用开发的 ELISA 方法，所有这些零售样品均未检测到 STC，并用 LC-MS/MS 进行了确认。我们展示了一种快速、简单、可靠的方法，用于筛选小麦和玉米粉中的 STC。
