Quality and Disease Incidence of `Waimanalo Solo' Papaya following Forced-air Heat Treatments

Abstract

Papaya fruit (Carica papaya L. cv. Waimanalo Solo), at color break ripeness, were either not heated (controls) or forced-air heated to center temperatures of 47.5, 48.5, or 49.5 °C, and held at these temperatures for 20, 60, 120, or 180 minutes. Following heat treatment, fruit were hydrocooled until reaching a center temperature of 30 °C, treated or not treated with prochloraz, allowed to ripen at 26 °C and then assessed for quality. Treatment at 48.5 °C or 49.5 °C for ≥60 minutes was associated with skin scalding. No significant scald was observed in other treatments or in the controls. Both control and heat-treated fruit had relatively high levels of decay. Heat treatment increased the incidence of body rots but did not affect the incidence of stem-end rots. Prochloraz treatment significantly reduced the incidence of decay. With the inclusion of a prochloraz treatment to control postharvest decay, fruit tolerated treatments of 47.5 °C for up to 120 minutes, and 48.5 °C and 49.5 °C for 20 minutes with no significant damage. Chemical name used: 1-N-propyl-N-(2-(2,4,6-(trichlorophenoxy)ethyl)-1H-imidazole-1-carboxamide (prochloraz).