Extension of shelf-life of Penicillium digitatum infected sweet oranges by vapor heat treatment

A.T. Aborisade, O.O. Elufisan
Heat treatment protocols making use of hot water for postharvest decay control on oranges has the disadvantage of the water serving as source of inoculum for wounded fruits. Vapor heat (VH) has the potential of eliminating this problem. Orange fruits inoculated with P. digitatum, exposed to vapor heat as steam at 55 and 60°C, stored at tropical ambient temperature (28-30°C) had extended shelf-life. Exposure at 55°C for 25, 30 and 35 min and 60°C for 30, 35 and 40 min were observed to preserve fruits for a minimum of 40 days compared to the control fruits that had started showing decay symptoms on day 6 post treatment. Inoculated fruits exposed to vapor heat at 60°C for 30 min remained disease free for 100 days. In vitro studies indicated that exposure to vapor heat did not significantly affect the germination of spores of P. digitatum but significantly reduced germ tube extension, showing that the treatment was effective due to prevention of fungal mycelium from growing into and colonizing the host despite spore germination. Vapor heat treatment is recommended for routine postharvest treatment of sweet oranges for significant extension of storage life at tropical ambient storage.
Aborisade, A.T. and Elufisan, O.O. (2021). Extension of shelf-life of Penicillium digitatum infected sweet oranges by vapor heat treatment. Acta Hortic. 1325, 41-46
DOI: 10.17660/ActaHortic.2021.1325.7
https://doi.org/10.17660/ActaHortic.2021.1325.7
vapor heat, sweet orange, decay, Penicillium infection, ambient storage
English

Acta Horticulturae