Effects of gamma irradiation followed by climatization on the quality of 'Prata' banana (Musa acuminata x Musa balbisiana, AAB)

Banana is a highly perishable climacteric fruit. In order to ensure fast and homogeneous ripening that will make its processing and commercialization easier, it is usually treated by climatization. On the other hand, irradiation is an interesting physical process capable of delaying ripening and extending the shelf life of fruits. This work investigated the competing effects of irradiation followed by climatization on the quality of 'Prata' banana (Musa acuminata x Musa balbisiana, AAB). All fruits were harvested in the preclimacteric stage, rinsed and stored at 27 deg C after being submitted to five different treatments. After hygienization, four out of five samples were exposed to gamma-ray at doses of 0.25 and 0.50 kGy. The unirradiated fruits were left for control and half of the irradiated samples were then climatized by exposure to CaC2. Measurements of fresh mass loss, total soluble solids, peel coloration and disease index were performed on five different dates for up to nine days in order to monitor quality and the degree of ripening. It was found that high temperatures prevailing during climatization and storage accelerated maturation in all fruits in spite of the use of irradiation, with the control becoming ripe in 3 days only. In addition, based on the consistent results from the experiments performed, it can be concluded that irradiation at the doses tested was unable to overcome the maturation effects produced by climatization. However, the sole use of irradiation with 0.25 kGy yielded the lowest figures for fresh mass loss and disease index in the samples, thus becoming the most attractive among the treatments tested. (author)