A follow-up study on the quality of maize for sale in West African public markets was carried out in Benin and Niger from August 15–28, 2013. Complementing the earlier study, this present assessment included not only retailers but also wholesalers and maize producers. Samples were evaluated for parameters related to the physical quality of the maize and for aflatoxin contamination. Most maize value chain actors process their offered grain using traditional methods for threshing, winnowing and drying. Maize for sale in the markets surveyed had an average moisture content ranging between 12 and 14%. Non-grain impurities amounted to 0–2.3% while mouldy grains ranged between 0.2 and 0.8%. The impurity level in grain was three times higher among wholesalers compared to retailers and producers. An insect pest, the Larger Grain Borer (Prostephanus truncatus (Horn) was found only in Benin but Sitophilus zeamais Motschulsky, Cryptolestes ferrugineus Stephens, and Tribolium castaneum Herbst, were present in maize for sale in the markets in of both countries. Insect pest frequency was 16 times higher in wholesalers' grain compared to that of retailers and producers. Aflatoxin levels exceeding the accepted standard of 20 ppb were noted in markets in both countries. The highest proportion of aflatoxin-contaminated maize was in wholesalers’ grain in Malanville market.

中文翻译：

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贝宁和尼日尔市场销售的玉米质量


2013 年 8 月 15 日至 28 日，在贝宁和尼日尔对西非公共市场销售的玉米质量进行了后续研究。作为对早期研究的补充，本次评估不仅包括零售商，还包括批发商和玉米生产商。对样品进行了与玉米物理质量和黄曲霉毒素污染相关的参数评估。大多数玉米价值链参与者使用传统的脱粒、风选和干燥方法来加工其提供的谷物。接受调查的市场上出售的玉米平均含水量在 12% 至 14% 之间。非谷物杂质含量为0-2.3%，霉变谷物含量为0.2-0.8%。批发商的谷物杂质含量是零售商和生产商的三倍。大型谷物螟 (Prostephanus truncatus (Horn)) 等害虫仅在贝宁发现，但两国市场上出售的玉米中都存在 Sitophilus zeamais Motschulsky、Cryptoletes ferrugineus Stephens 和 Tribolium castaneum Herbst。两国市场上批发商的谷物中黄曲霉毒素含量比零售商和生产商高出 16 倍。马朗维尔市场的批发商谷物中受黄曲霉毒素污染的比例最高。