Effect of maturity stage at harvest and storage conditions on the ripening behavior of Pococi hybrid papayas

Abstract

Papayas (Híbrido Pococí) were harvested from a field in Cariari, Guapiles, Costa Rica, with 4 maturity degrees, which were defined by the number of yellow stripes on the surface of the fruit (0, 1, 2 or 3 stripes). The objective was to understand changes in the physico-chemical characteristics that occur in papayas under 2 storage conditions: 1) 22ºC and 85% RH (RT), or 2) 14ºC and 95% RH (CT), both during 14 days, followed by room temperatures storage for 9 more days. At the beginning of the storage at RT (22ºC), respiration rates of the fruits were low 6.3 to 13.3 ml.kg^-1.h^-1 CO₂, then an abrupt increase was observed between day 3 and 5. Fruit respiration rates did not differ among treatments after 7 days, regardless of the differences in color stripes number at harvest (0, 1, 2 or 3 stripes). Yellow coverage of the skin reached 75% of total area, after 7 days of storage for fruits picked with 2 or 3 yellow stripes, while fruits with one 1 stripe at harvest reached that color until day 9. Pulp firmness decreased throughout storage, reaching values below 20 N (good for consumption) at day 7 (2 and 3 stripes) and 9 (1 stripe) of storage at RT. After storage at 14ºC, fruit harvest at 1, 2 or 3 stripes showed similar respiration rates; an important increase was observed at day 5 at room temperature. Development of the skin color increased for all stripes between day 3 and 7, reaching 75% of total at day 7. Skin and pulp firmness of papaya fruits significantly decreased to 83% and 90%, respectively, after stored at 14ºC. On the other hand, soluble solids content (SSC) and titratable acidity (TA) did not significantly varied during storage.