The ozone fumigation system, located in the postharvest laboratory, School of Biosciences, University of Nottingham, Malaysia campus, was comprised of chambers constructed from 5 mm thick polycarbonate (112.0 cm length × 47.0 cm width × 43.0 cm height)and equipped with four 12 V fans positioned directly below the sample platform to ensure a well-mixed atmosphere. The chambers were ventilated with HEPA particulate-filtered air. Ozone was introduced to the chamber by an ozone generator (Model MedKlinn Professional Series, MedKlinn International Sdn. Bhd., Malaysia)and the ozone concentration was controlled manually using a sensor (Eco-Sensor, Model OEM-2, MedKlinn International Sdn. Bhd.,Malaysia).