The Effect of Ozonation on the Chemical, Microbial and Sensory Properties of Rice Flour

The objective of this study was to achieve optimal conditions using ozone gas to maintain or improve the quality and reduce the microbial contamination of rice flour.

In this research, ozone gas was injected at the rate of 10, 20 and 30 g/h and grazing time (extinction treatment) of 15 and 30 minutes and after completing the exoneration, the specimens were examined at room temperature for 60 days.

The results showed that ozone gas had no significant effect on the moisture content of the samples (p> 0.05) but treatment with ozone gas had significant effect on pH and peroxide value of rice bran (p <0.05). Coliforms were only detectable in the control sample and negative results were reported in ozone treated samples at different concentrations and time of induction. Increasing ozone concentration significantly reduced the total count of microorganisms and mold and yeast in rice flour samples (p <0.05). Therefore the highest count was in the control sample and the lowest count was in the sample treated with ozone gas at the concentration of 30 g/h. The sensory characteristics of the control sample were higher than other samples, which was significant at the concentration of 20 and 30 g/h of ozone gas (p <0.05).

In conclusion, the best chemical, microbial and organoleptic characteristics of rice flour treatments were obtained at 10 g/h and 15 min.