Preservation of peanuts, also called groundnuts, is a delicate subject. Conservation of peanuts like the Runner, Spanish, Virginia or Valencia varieties, means preserving their sensory attributes by fighting the development of rancidity and off-flavors through lipid oxidation.
According to the Food and Agricultural Organization (FAO), 25% of the world’s food crops are significantly contaminated with mycotoxins (Boutrif and Canet, 1998). In the peanut industry this reality is very present in day to day affairs. Significant deterioration caused by mold occurs during storage and, as a consequence, the development of aflatoxins.
Polypropylene bags are not airtight, and groundnut pods are susceptible to fungal and aflatoxin contamination (Hell et al., 2000; Udoh et al., 2000)
It has also been observed that pods stored in jute bags are significantly higher in moisture content, mold growth, aflatoxins, and free fatty acid content, than those stored in polyethylene-doubled bags (Bulaong and Dharmaputra, 2002).
The approach of VacQPack is higher in quality, using a liner of 7 layers and 200 microns, that ensures no condensation problems in raw peanuts packaged and shipped by container. This feature is especially important when peanuts are shipped to northern hemisphere latitudes during winter time, where they will experience drastic and swift changes of temperature. This situation, frequently observed in transoceanic voyages is responsible for a considerable amount of spoilage due to condensation, which causes rancidity.
Oxidation is the most direct risk in the preservation of groundnuts/roasted peanuts. Peanuts’ sensitivity to oxidation is very high, so their packaging must reach a modified atmosphere with oxygen (O2) levels below 4%, even in large bulks.
Regarding pests, Indianmeal moth is considered to be the most serious pest, followed by the red flour beetle, the merchant grain beetle, the almond moth, and cockroaches (Blatella germanica and Peripalneta americana). Application of Carbon Dioxide CO2 at low pressure and using storage temperature as an ally have proven to be effective ways of organically controlling and killing pests.
Traditional chemical treatments of peanuts are: malathion, synergized pyrethrum, diatomaceous earth (DE), and fumigation using phosphine gas. Methyl bromide was a commonly used fumigant in the peanut industry, but it is now forbidden. Chemical options can be replaced by organically compliant fumigation with a lower impact on the environment, less health risks, and are effective worldwide.