Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/20/2008
Publication Date: 12/1/2008
Citation: Wall, M.M., Khan, S. 2008. Postharvest quality of dragon fruit (Hylocereus spp.) after x-ray irradiation quarantine treatment. HortScience. 43(7):2115-2119.
Interpretive Summary: The quality and composition of dragon fruit, a high-value, exotic tropical fruit was determined after low dose irradiation to establish the limits of fruit tolerance to this quarantine treatment. Quality was maintained following irradiation doses up to 800 Gy. This research supports a USDA, APHIS rule allowing the export of irradiated dragon fruit from Hawaii. Exporters can develop markets for Hawaii's dragon fruit with confidence that fruit quality will not be compromised by irradiation treatment at a maximum dose of 800 Gy.
Technical Abstract: The quality of three dragon fruit clones (Hylocereus sp.) was determined following x-ray irradiation for disinfestation of quarantine pests. Fruit were treated with irradiation doses of 0, 200, 400, 600, or 800 Gy and stored for 12 days at 10 °C. Irradiation did not affect soluble solids content, titratable acidity, or fructose concentrations. Glucose, sucrose, and total sugar concentrations decreased linearly as dose increased. Minimal softening occurred in the outer flesh layers for fruit treated with 400 or 600 Gy irradiation. Surface color, peel injury, and bract appearance differed among the three clones with irradiation stress, but in all cases visible changes were minor. Fruit decay was absent or minimal, and disease ratings were not affected by irradiation. Irradiation treatment of dragon fruit at doses = 800 Gy would ensure visual and compositional quality while providing quarantine security.