Small hermetic bags (50 and 100 kg capacities) used by smallholder farmers in several African countries have proven to be a low-cost solution for preventing storage losses due to insects. The complexity of postharvest practices and the need for ideal drying conditions, especially in the Sub-Sahara, has led to questions about the efficacy of the hermetic bags for controlling spoilage by fungi and the potential for mycotoxin accumulation. This study compared the effects of environmental temperature and relative humidity at two locations (Indiana and Arkansas) on dry maize (14% moisture content) in woven polypropylene bags and Purdue Improved Crop Storage (PICS) hermetic bags. Temperature and relative humidity data loggers placed in the middle of each bag provided profiles of environmental influences on stored grain at the two locations. The results indicated that the PICS bags prevented moisture penetration over the three-month storage period. In contrast, maize in the woven bags increased in moisture content. For both bag types, no evidence was obtained indicating the spread of Aspergillus flavus from colonized maize to adjacent non-colonized maize. However, other storage fungi did increase during storage. The number of infected kernels did not increase in the PICS bags, but the numbers in the woven bags increased significantly. The warmer environment in Arkansas resulted in significantly higher insect populations in the woven bags than in Indiana. Insects in the PICS bags remained low at both locations. This study demonstrates that the PICS hermetic bags are effective at blocking the effects of external humidity fluctuations as well as the spread of fungi to non-infected kernels.

中文翻译：

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储存环境对气密保鲜袋功效的影响


一些非洲国家小农使用的小型密封袋（容量为 50 公斤和 100 公斤）已被证明是防止昆虫造成的储存损失的低成本解决方案。采后操作的复杂性和对理想干燥条件的需求，尤其是在撒哈拉以南地区，引发了人们对密封袋控制真菌腐败的功效和霉菌毒素积累的可能性的质疑。本研究比较了两个地点（印第安纳州和阿肯色州）的环境温度和相对湿度对聚丙烯编织袋和普渡农作物改良储藏 (PICS) 密封袋中的干玉米（含水量 14%）的影响。放置在每个袋子中间的温度和相对湿度数据记录仪提供了环境对两个地点储存谷物的影响概况。结果表明，PICS 袋在三个月的储存期内可防止水分渗透。相比之下，编织袋中的玉米含水量有所增加。对于这两种袋子类型，没有获得证据表明黄曲霉从定植玉米传播到邻近的非定植玉米。然而，其他贮藏真菌在贮藏过程中确实有所增加。 PICS袋中的感染籽粒数量没有增加，但编织袋中的感染籽粒数量显着增加。阿肯色州温暖的环境导致编织袋中的昆虫数量明显高于印第安纳州。两个地点的 PICS 袋中的昆虫数量仍然很低。这项研究表明，PICS 密封袋可以有效阻止外部湿度波动的影响以及真菌向未受感染的籽粒的传播。