Niyibituronsa M, Onyango A N, Gaidashova S, Imathiu S M, Uwizerwa M, Wanjuki I, Nganga F, Muhutu J C, Birungi J, Ghimire S, Raes K, De Boevre M, De Saeger S, Harvey J
Rwanda Agriculture Board, Rwanda, P.O. BOX 5016 Kigali, Rwanda.
Jomo Kenyatta University of Agriculture and Technology, Kenya, P.O. BOX 62000 (00200) Nairobi Kenya.
Afr J Food Agric Nutr Dev. 2018;18(3). doi: 10.18697/ajfand.83.17710.
Soybean is a critical food and nutritional security crop in Rwanda. Promoted by the Rwandan National Agricultural Research System for both adults and as an infant weaning food, soybean is grown by approximately 40% of households. Soybean may be susceptible to the growth of mycotoxin-producing moulds; however, data has been contradictory. Mycotoxin contamination is a food and feed safety issue for grains and other field crops. This study aimed to determine the extent of mycotoxin contamination in soybean, and to assess people's awareness on mycotoxins. A farm-level survey was conducted in 2015 within three agro-ecological zones of Rwanda suitable for soybean production. Soybean samples were collected from farmers (n=300) who also completed questionnaires about pre-and post-harvest farm practices, and aflatoxin awareness. The concentration of total aflatoxin in individual soybean samples was tested by enzymelinked immunosorbent assay (ELISA) using a commercially-available kit. Other mycotoxins were analyzed using liquid chromatography-mass spectrometry (LCMS/MS) on 10 selected sub samples. Only 7.3% of the respondents were aware of aflatoxin contamination in foods, but farmers observed good postharvest practices including harvesting the crop when the pods were dry. Using enzyme-linked immunosorbent assay (ELISA), only one sample had a concentration (11 µg/kg) above the most stringent EU maximum permitted limit of 4 µg/kg. Multi-mycotoxins liquid chromatography-mass spectrometry (LC-MS/MS) results confirmed that soybeans had low or undetectable contamination; only one sample contained 13µg/kg of sterigmatocystine. The soybean samples from Rwanda obtained acceptably low mycotoxin levels. Taken together with other studies that showed that soybean is less contaminated by mycotoxins, these results demonstrate that soybean can be promoted as a nutritious and safe food. However, there is a general need for educating farmers on mycotoxin contamination in food and feed to ensure better standards are adhered to safeguard the health of the consumers regarding these fungal secondary metabolites.
大豆是卢旺达重要的粮食和营养安全作物。在卢旺达国家农业研究系统的推广下，大豆既作为成人食品，也作为婴儿断奶食品，约40%的家庭种植大豆。大豆可能易受产霉菌毒素霉菌的生长影响；然而，数据一直相互矛盾。霉菌毒素污染是谷物和其他大田作物的食品和饲料安全问题。本研究旨在确定大豆中霉菌毒素污染的程度，并评估人们对霉菌毒素的认识。2015年在卢旺达适合大豆生产的三个农业生态区进行了农场层面的调查。从农民那里收集了大豆样本（n = 300），这些农民还完成了关于收获前和收获后农场操作以及黄曲霉毒素认识的问卷。使用市售试剂盒通过酶联免疫吸附测定（ELISA）检测单个大豆样本中总黄曲霉毒素的浓度。对10个选定的子样本使用液相色谱 - 质谱联用（LC - MS/MS）分析其他霉菌毒素。只有7.3%的受访者意识到食品中的黄曲霉毒素污染，但农民们采取了良好的收获后操作，包括在豆荚干燥时收获作物。使用酶联免疫吸附测定（ELISA），只有一个样本的浓度（11微克/千克）高于欧盟最严格的4微克/千克最大允许限量。多霉菌毒素液相色谱 - 质谱联用（LC - MS/MS）结果证实大豆的污染水平较低或未检测到；只有一个样本含有13微克/千克的柄曲霉素。卢旺达的大豆样本霉菌毒素水平低到可以接受。与其他表明大豆受霉菌毒素污染较少的研究一起，这些结果表明大豆可以作为一种营养安全的食品来推广。然而，总体上需要对农民进行关于食品和饲料中霉菌毒素污染的教育，以确保遵守更好的标准，保障消费者关于这些真菌次生代谢产物的健康。
