S21 - Session O3 - On the use of hot water treatment to control postharvest diseases of export grown banana fruit (Musa sp., Group AAA, subgroup Cavendish, cv. Williams)

Authors: Simón Uribe-Palacio, Maricruz Ramírez-Sánchez *, Gerardina Umaña-Rojas, Marco Vinicio Sáenz-Murillo

International markets set stricter regulations of pesticide residues to make produce safer for human consumption. Hot water treatment (HWT) is a viable physical treatment to replace fungicides used for quality preservation of bananas. Most experiments with HWT were performed with bananas grown in small-scale farms, and with minor cultivars. Our study revisited HWT using bananas grown under commercial orchards for the mainstream market. A set of two experiments were carried out, for the first one, HWT of 45 °C; for 10, 15, and 20 min, 50 °C for 5, 10, 15, and 20 min, and 55 °C for 1, 2, 3, 4 and 5 min were applied by dipping the fruit in a 600-L heated tank. In the second experiment, freshly harvested fruit was cut in clusters, cleaned, and disinfected in a commercial packing house, then inoculated with agents of crown rot and mold ( Fusarium semitectum (1x10 4 ) + Fusarium proliferatum (1x10 4 ) + Colletotrichum musae (1x10 3 )), and exposed to 55 °C for 1, 2, and 3 min, or 50 °C for 1, 3 and 5 min. In both experiments fruit was subjected to transport simulation 21 days at 14 °C and 85-90 % R.H., then commercially ripened and exposed to shelf-life conditions (20 °C and 80 % R.H.). Quality and pathological variables were evaluated. Results showed that HWT of 55 °C for 1, 2 and 3 min and 50 °C for 1, 3 and 5 min suppresed pathogens growth at crown and peel. Some re-infection with Fusarium spp may occur after HWT during transit to market, since these fungi are dispersed by air and grow in many surfaces. Treatments did not affect green life, ripening, and quality of the fruit. Previously published research suggest that delatexing time may be reduced by HWT, therefore no impact on total processing time is expected.