Impact of storage environment on the efficacy of hermetic storage bags

Abstract

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.

Effects of storage structures and moisture contents on seed quality attributes of quality protein maize

“…Similarly, Data logger placed inside the hermetic bags-PICS and woven polypropylene bag did not get fluctuate on its internal environmental profiles in two different locations and found no penetration of moisture too. (Lane & Woloshuk, 2017). …”

Changes in the Fungal Microbiome of Maize During Hermetic Storage in the United States and Kenya

“…The current study stems from two previous studies in the United States and Kenya that examine the efficacy of storing maize in hermetic bags to reduce the risk of mycotoxin accumulation during storage. In both studies, maize was sealed in hermetic and woven bags and stored for 3 months at three locations, Indiana and Arkansas, United States, and Makueni County, Kenya ( Maina et al, 2016 , 2017 ; Lane and Woloshuk, 2017 ). Maize stored in the United States was harvested from a single source, while in Kenya individual farmers grew, dried and stored the maize at their farms.…”

Mycotoxin concentrations in rice from three climatic locations in Africa as affected by grain quality, production site, and storage duration

“…Temperature and relative humidity showed an increasing trend in all storage rooms from the start to the end of storage period. Although the optimum conditions for fungal spore germination and proliferation are different from those for mycotoxin production, temperature (15.8–34.9°C) and humidity (34.2%–89.7%) ranges in the study sites were in the intervals reported as suitable for both microbial growth (Choi et al, ; Garbaba, Diriba, Ocho, & Hensel, ; Lane & Woloshuk, ) and mycotoxin production (Choi et al, ; Lane & Woloshuk, ; Murphy, Hendrich, Landgren, & Bryant, ) in cereals including rice. The optimum temperature for the growth of Aspergillus spp.…”