Reduction of fungi and mycotoxin decontamination by ozone gas treatment in three stored rice (Oryza sativa L.) varieties

Abstract

The present work brings together different rice varieties (black, brown and white) evaluated for their differences/ susceptibilities/resistance to ozone (O3) gas treatment for safer storage (mycological and toxicological contamination control). The three rice varieties were separated into two Groups –Control (GC) andtreated Groups (GT) which had O3 gas applied (5 L/min, 40 ppm and 60 min for gas flow). Samples were collected during the storage period to check for the O3 gas effect on fungi reduction (total count and fungi genera identification) and so for the humidity parameters of moisture content (mc) and water activity (aw). It was possible to verify the effectiveness of the O3 application in the samples when compared to Control. It was observed that even at the shortest time of gas exposure, O3 application caused changes to fungi (both growth speed & toxin formation). The grains did not change their organoleptic, physical and biochemical characteristics after O3 application. Recent studies from our Labmico Group indicated that the O3 application in addition to prevention of the biological contaminants, as reported in the current work, also reduces an insecticide (deltamethrin) residues. As O3 treated grain has reduced fungi contamination and toxicity of rice grains in all the varieties studied, it can be considered a potential agent to control fungi spoilage and so for toxigenic strains. Considering that there is a growing concern on the use of agrochemicals and their harmful effects on human health and the environment, O3 application can be a promising to implement decontaminationof highly consumed grains worldwide, such as rice.

Keywords

• rice
• fungi
• storage
• ozone
• mycotoxins