Ozonation as a promising approach to improve stored rice quality in Ghana

Background Two species of rice pests that are responsible for postharvest losses, the rice weevil ( Sitophilus oryzae ) and the Angoumois moth ( Sitotroga cerealella ), are major destructive pests responsible for paddy grain deterioration. A benchtop custom‐built model of ozone‐generating equipment from ozone generator DKM‐10GY, producing 2000 ppm with a continuous flow rate of 0–23 mg/L, has demonstrated an effective means of seed treatment; hence, it was used at the entomology laboratory of Council for Scientific and Industrial Research (CSIR) to solve major limitations associated with conventional paddy rice handling, including seed quality deterioration and human health concerns. Approximately 0.2 g of an estimated 100 mature weevils and moths were incorporated into 5.0 kg of the infested Nerinca 14 rice variety, then the seed quality, seed germination, mortality rate, optimal ozone application rates, and unused ozone were determined. Results Ozone demonstrated strong antimicrobial properties and could be used as an alternative form of insect control, as it presents a promising opportunity to improve safety and quality at optimal levels via the use of gaseous ozone. Lower mortality rates were recorded at O 1 and O 2 , ranging from 80% to 85%, whereas the remaining application rates presented 95%–100%. Significant differences ( p < 0.05) existed between the rates of supplied ozone and unused ozone. No significance was recorded for the germination rates of O 3 , O 6 , and O 8 ( p > 0.05) (99%), while O 4 treatment produced the highest germination rate of 100%, which was also statistically significant ( p < 0.05). The preliminary examination demonstrated that lower‐than‐optimum ozone injection rates could kill some insect pests, whereas higher ozone application rates recorded lower seed viability and germination rates. Conclusion This preliminary study demonstrated ozonation's effectiveness in decontaminating food grains, attributed to specific ozone concentrations, constant pressure, and flow rates that inactivate microorganisms. Ozone outperforms traditional preservation methods due to its strong oxidation properties and broad antibacterial spectrum. Treatment O 4 achieved the highest germination rate (100%), while higher ozone levels O 9 negatively impacted rice germination. Ozone application at optimal rates significantly increased rice weevil mortality, achieving complete mortality at depths of 1 cm and 3 cm. Statistical analyses indicated significant differences in the grain preservation effects over varying storage periods. The results advocate for the commercialization of this technology to reduce postharvest losses in northern Ghana, thereby enhancing food production and alleviating poverty.