Hot water treatments to control internal rot of ‘MD-2’ pineapple fruit caused by Fusarium verticillioides

Abstract

Postharvest fungal infections in LSQUOMD-2RSQUO pineapple (Ananas comosus) fruit cause the majority of losses during export. The leading strategy for decay control is the use of synthetic fungicides, but constraints associated with the use of these products have led to the search for alternative methods to reduce fungal infections. Hot water treatments have the potential to improve the postharvest life on various fruits by controlling the germination of several pathogens. In this research, the efficacy of hot water dips at several temperatures and times for the control of Fusarium verticillioides rot of pineapple during cold storage was assessed. Results showed that, relative to untreated fruit, pineapples treated with the fungicide prochloraz (3 cm3 L(‑1)) resulted in a 59.2% disease reduction after 21 days storage at 8°C and 90% RH; on the other hand, fruits immersed at 40°C for one minute resulted in a 35.3% reduction in F. verticillioides, whereas the reduction in internal fruit rot in pineapples dipped at 50°C for one minute was 22.4%. Moreover, during storage for 21 days at 8°C, treatment at 40°C for one minute significantly (p<0.05) reduced weight loss, maintained firmness of pineapple and slowed changes in soluble solid content (SSC), titratable acidity (TA) and pH. In conclusion, the results suggest that a dip at 40°C for one minute may reduce internal fruit rot produced by F. verticillioides during postharvest storage without any negative effect on physicochemical quality. It is a residue-free method, respectful of human health and the environment.