Preservation of cereal grains in nitrogen atmospheres

Abstract

The disinfestation of cereal grains by means of inert atmospheres is the simplest and least costly physical method to be used as an alternative to chemical treatments in temperate and hot climate zones. For the purpose of replacing the interstitial atmosphere of gas-tight storage bins, nitrogen is particularly suitable, as it is biologically inert and easily available on the market both in gaseous and liquid form. It can be utilized for short fumigations (approx. 20 days) and for the protracted storage of dry (years) and of medium to high moisture content cereals (months), since in the presence of low residual concentrations of oxygen (< 0.3%) the proliferation of moulds is significantly retarded.

This paper describes some of the storage experiments carried out with cereals in technical (O₂ ≤0.5%) and pure nitrogen. The results of soft wheat at low (< 14.5%), medium (16%) and high (17–18%) moisture content as well as of hard wheat preservation, attest the safety of the method and point out its advantages as compared with storage in air. The economics of the storage technique in nitrogen are advantageous, the operating costs being significantly lower than those of traditional storage methods, based on chemical insecticidal treatments or refrigeration.