Evaluation of the quality and shelf life of gamma irradiated blueberries by quarantine purposes

Fresh blueberries (Vaccinium spp.) are considered one of the richest sources of phenolic compounds and are appreciated for their high antioxidant capacity. But they are hosts in Argentina of the quarantine pests Ceratitis capitata and Anastrepha fraterculus, and have to be treated to avoid its spreading. Irradiation is being introduced in the Agricultural World trade, increasing exponentially on the last years. In order to guarantee the success of this process, it is required previous to the rutinary treatment, to define the irradiation dose range to be applied. The minimum dose for these pests has been already approved in the IPPC standard 28. The maximum dose depends on the tolerance of the fruit cultivars, maturity, pre-harvest conditions, harvest time, storage conditions, and interactions among these factors. The postharvest quality of Argentina´s blueberry treated with irradiation doses of 150 (generic quarantine dose used for fruit flies) and 300 Gy (to evaluate tolerance) was evaluated. The studies included blueberries from different harvest seasons 2009-2012). Misty, O'Neal and Emeral varieties were chosen, because they represent the biggest volume of exported blueberry from Argentina. The results indicated that irradiation at 150 Gy and 300 Gy did not significantly affect the postharvest quality and slightly improved shelf life of the different blueberries varieties. Therefore, it is possible to use irradiation as an alternative quarantine treatment for Argentina´s blueberries, establishing a dose range appropriate to be applied on a commercial irradiation facility.