Exposure-time optimization of ozone fumigation against two Tribolium flour beetles: integrating insect suppression, oxidative stress, and wheat flour quality.

BACKGROUND: Stored wheat flour is highly susceptible to infestation by Tribolium castaneum and Tribolium confusum. This laboratory-scale study evaluated how ozone exposure duration at 1000 ppm affected insect suppression, reproductive performance, oxidative stress, infestation-associated flour weight loss, and flour quality.

RESULTS: Larvae and adults were exposed for 0, 5, 10, or 15 h. After 15 h, mortality reached 94.56% and 90.56% in T. castaneum and T. confusum adults and 81.92% and 77.44% in their larvae, respectively. F₁ progeny suppression reached 97.34%, 95.18%, 91.67%, and 87.91% in the corresponding groups. Longer exposures reduced fecundity, progeny production, and adult longevity, while increasing SOD, CAT, GST, and MDA. Among flour-related outcomes, infestation-associated flour weight loss declined. Moisture, crude protein, crude fat, total phenolics, and oil content also declined modestly, whereas peroxide value and free fatty acids increased. The 15 h treatment produced the greatest biological suppression, while 10 h showed a favourable laboratory-scale balance between insect control and the measured flour-quality responses.

CONCLUSION: Ozone produced a coordinated duration-dependent reduction in Tribolium survival and population-recovery potential, together with measurable oxidative and flour-quality changes. Integrating mortality, reproductive impairment, physiological stress, and commodity-damage indicators provides a more comprehensive framework than mortality-only assessment. However, the 10 h treatment should be regarded as laboratory-scale proof of concept rather than a commercial recommendation. Validation in larger flour masses, with chamber monitoring and rheological, sensory, structural, and digestibility assessments, is required. © 2026 Society of Chemical Industry.