World Grain - July 2016 - 64

GRAIN OPERATIONS

Monitoring CO2 in stored grain
Carbon dioxide sensors can provide early detection of spoilage
by Dirk Maier

Millions of dollars are lost worldwide due to mold (fungi)
and insect-related spoilage during grain storage resulting
in substantial economic losses for farmers and stored grain
managers. Maintaining stored grain quality requires a combination of multiple tools and practices to ensure that the
quality and quantity of grain entering the storage facility
does not deteriorate over time. Despite decades of research
and the availability of advanced monitoring technology,
combating pre- and post-harvest mold infection and insect
infestation during storage remains a challenge throughout
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moisture are managed.
Molds are the primary cause of spoilage in stored grain.
They can cause detrimental changes in appearance, quantity
and quality, thus reducing the end use value for food, feed and
biofuel. More importantly, some mold species can produce
toxic substances known as mycotoxins. These are secondary
metabolites produced by a group of molds that belong mainly
to the Aspergillus, Fusarium and Penicillium genera.
Preventing these toxins from entering the food and feed
value chains is a major concern of the global grain and feed
industry. Worldwide, approximately 25% of food crops are affected by mycotoxins causing millions of tonnes of food stuff
lost each year. As a result, grain producers (including smallholder farmers) and grain handlers (including processors and
64

exporters) often suffer the consequences of reduced marketability of their commodities in the form of discounts or outright rejection both domestically and internationally.
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suppress the immune system, reduce nutrient absorption and
cause stunting in young children, cause cancer, and are lethal to humans and animals in high doses. Human exposure
is the result of ingestion of contaminated grain foods, or indirectly from consumption of food of animal origin previously
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The economic impact of mycotoxins includes loss of human
and animal life, increased health care and veterinary care
costs, reduced livestock production, disposal of contaminated
foods and feeds, post-harvest loss of crops, and higher cost for
regulatory programs directed toward mycotoxins.
The early detection of spoilage due to insects and molds
during grain storage is essential to keep them at levels
where they do not cause grain spoilage and affect economic
value. Grain sampling methods are tedious and time consuming, especially when sample analysis is involved such
DV PROG LVRODWLRQ DQG HQXPHUDWLRQ DQG LQVHFW LGHQWL¿FDtion. Informal surveys of farmers in the midwestern United
States indicate that they check their stored grain only every
four to six weeks, primarily visually and by odor. That is
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and cause spoilage, especially when excess moisture has
July 2016 / World Grain / www.World-Grain.com
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World Grain - July 2016

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