COMPARATIVE RADIATION DOSE MAPPING OF SINGLE FRUIT TYPE AND MIXED‐FRUIT BOXES FOR EXPORT FROM HAWAII

A generic radiation quarantine treatment of 400 Gy for insect pests infesting fresh fruit and vegetable and other horticultural commodities was recently approved in the U.S.A. Dose‐mapping studies were conducted to compare dose variation during radiation treatment at 400 Gy of a single‐fruit type and of mixed fruits packed in boxes. The tests included papaya, mango, banana, rambutan, longan, dragon fruit and various combinations of these tropical fruits. When radiation was applied to a single box containing one type of fruit or a mixture of two or three fruit types, measured doses were sometimes higher in the mixture. Irradiation of a simulated commercial load of 12 boxes resulted in no significant difference between single‐fruit boxes and mixed‐fruit boxes. In all experiments, the technical objectives of radiation treatment were met, meaning that all resulting doses fell between the minimum required dose of 400 Gy and the maximum allowable dose of 1,000 Gy.PRACTICAL APPLICATION Quarantine treatment protocols to disinfest fresh agricultural commodities of quarantine insect pests are traditionally developed for single commodities. No postharvest quarantine treatment has ever been approved for mixed fresh commodities. The information contained herein using a generic radiation dose will be submitted to regulatory authorities to gain approval for the first disinfestation treatment for mixed fresh commodities. This could lead to export approvals for value‐added mixed‐fruit gift boxes or other products which would diversify revenue for the tropical fruit industry.