Effects of ionizing radiation on papayas (<i>Carica papaya</i>) fruit

Abstract

The effects of ionizing radiation on papaya fruits were investigated with a particular interest on the disinfection and ripening. Twelve samples of papayas fruit, each weighing between 400 – 450 g were irradiated over four different regimes of radiation doses: 0.25, 0.50, 0.75 and 1.00 kGy, using a cobalt-60 gamma irradiation facility, with source strength of 1.11 x 10¹⁶Bq. The samples were subjected to a temperature of about 9.8^OC in control chamber 14 days before irradiation, after which they were subjected to the same temperature condition. Physical analyses were carried out on each set of the samples 1 day before irradiation, then 3 and 7 days after irradiation respectively. The samples were also analyzed 14, 19 and 21 days after irradiation at a temperature of 24.8^OC. The irradiated samples showed a slower yellow color development, which may be attributed to the effect of ionizing radiation. Of the four different regimes of radiation doses, 0.50 - 0.75 Gy was identified as the optimal range of radiation dose for effective delay in ripening of papayas fruit.

Keywords: Carica papaya, fruit ripening, ionizing radiation, irradiation, disinfection

International Journal of Natural and Applied Sciences, 7(1): 29 - 31, 2011