Monitoring & metering
Food security is a growing issue around the world and food storage and preservation is an important aspect of this. Storage of grains is typically done in modified environments. However, the chemical composition of the atmosphere in a grain bin is not a static one - stored seeds and cereals produce carbon dioxide and carbon monoxide gases. To ensure that modified atmospheric conditions in bins are kept at their optimum ranges, sensors, like those produced by Edinburgh Sensors, are used
G
uaranteeing food supplies is a growing issue. With a growing global population, climate change and ocean
acidification disrupting crops and fish stocks, many countries face serious challenges in ensuring food security. As well as issues affecting food production worldwide, another important aspect for food security is food storage and preservation. Cereals are one of the key sources of calories
for the world’s nutritional needs. Maize, in combination with rice and wheat, provides at least 30 per cent of calories for more than 4.5 billion people, with developing countries most heavily dependent on these types of crop. However, when crops such as maize are stored, there are numerous ways that the crop can deteriorate and become wasted, including damage from humidity, insects, and microorganisms. It is estimated that $500 million to $1 billion of maize is lost in the developing world each year from these last two factors alone. This means there is a strong impetus both economically and for human health to improve cereal storage methods, reducing losses. Historically, it was common to use fumigants, gaseous pesticides, in barns to kill invasive insects and microorganisms but now, it has become more common to use modified atmospheric conditions to achieve the same goals with fewer concerns about health and safety.
Gascard NG measurements are unaffected by humidity and relative humidity
ModiFiEd ATMoSpHEric condiTionS A modified atmosphere, or controlled atmosphere, is one in which the normal ratio of gases in the air is replaced with a specific combination of gases, often for the purposes of food preservation. Modified atmospheres are commonplace now in food packaging and transport, where they can be used to extend the lifetime and quality of produce such as meat and fruit, reducing the need for preservatives. Storage of grains is typically done in
environments composed partly of carbon dioxide, nitrogen, and oxygen. Increased carbon dioxide concentrations and lowered oxygen concentrations can have a lethal effect on insects and increasing nitrogen and oxygen can be used to control the relative humidity of the environment, reducing deterioration of crops and the risk of spoilage. However, the chemical composition of the atmosphere in a grain bin is not a static one. Respiration of molds and insects can lead to elevated carbon dioxide levels and stored seeds and cereals produce small amounts of not just carbon dioxide but also highly toxic carbon monoxide gas. Carbon dioxide rates of production may also be a better and more effective way of the early detection of spoilage than monitoring other conditions in the storage area such as temperature.
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August 2019 Instrumentation Monthly
Cereal gas monitoring
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