FIELD: preservation of newly harvested grain with the use of organic substances. SUBSTANCE: method involves treating grain flow in electromagnetic superhigh frequency field with propionic acid including additive of chitosan; using specific preparation as chitosan source, said preparation being produced by sequential extracting of Mortierella exigua micromycet biomass with the use of non-polar extractant in above-critical state, water, alkaline, water, acid, water, alkaline, and water, followed by joining of first extract with solid residue. EFFECT: reliable storage of grain. 2 ex
