Abstract:
Aflatoxin contamination of maize remains a serious challenge in developing countries in the
tropics where it is pervasive due to favourable environmental conditions and high consumption
of maize. An assessment of the triple-layer hermetic bag and a conventional bag (polypropylene
bag) effectiveness to control the aflatoxin content in insect-free and insect-infested stored maize
was studied over a six month period at the farm level. Moisture content, temperature, relative
humidity, oxygen depletion, carbondioxide elevation and grain damage were analysed during
storage. Seasonal changes resulted in significant fluctuation in grain moisture content,
temperature and relative humidity in different storage bag technologies and storage environment.
Analysis of variance also showed significantly differences (p<0.05) in the degree of insect
damage and the corresponding levels of aflatoxins in hermetic and polypropylene bags. The
initial mean percentage damage and aflatoxin content of 1.24% and 38.2 ug/kg respectively, in
either storage bag technology increased significantly following seasonal changes and insect
metabolic activities. Prostephanus truncatus-infested maize in the polypropylene bags recorded
the highest damage (97.9%) with a corresponding aflatoxin level of 227.7 ug/kg after six (6)
months storage. An aflatoxins level (>70 ug/kg) was recorded in the triple-layer hermetic bags
despite the bags excellent prevention of insect activities (<5%) over the same period of storage.
Triple-layer hermetic bags have limited capacity to abate further accumulation of aflatoxins in
previously aflatoxin-contaminated grains in the tropics.
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