Lichter, A., Dept. Postharvest Sci. Fresh Produce, ARO, Volcani Center, Bet Dagan 50250, Israel
Dvir, O., Dept. Postharvest Sci. Fresh Produce, ARO, Volcani Center, Bet Dagan 50250, Israel
Ackerman, M., Dept. Postharvest Sci. Fresh Produce, ARO, Volcani Center, Bet Dagan 50250, Israel
Feygenberg, O., Dept. Postharvest Sci. Fresh Produce, ARO, Volcani Center, Bet Dagan 50250, Israel
Pesis, E., Dept. Postharvest Sci. Fresh Produce, ARO, Volcani Center, Bet Dagan 50250, Israel

Litchi fruits are fumigated after harvest with sulfur dioxide (SO 2) to prevent their rapid browning. SO 2 blocks enzymatic activity but bleaches the fruits and, if this process is followed by dipping the fruit in dilute hydrochloric acid, the appealing red color is regained. Hot water brushing (HWB) is among the alternative methods that were developed to replace the use of SO 2. HWB reduced fungal population size on the surface of the fruit peel after treatment but did not eliminate fruit infection after storage. Whereas untreated fruits were infected with a variety of fungal species, Penicillium sp. was the only fungus that developed on the pericarp after storage in fruits that had been dipped in 1.5M HCl. Fruit treated by HWB followed by handling and storage under sterile conditions suffered greater decay than fruit stored under non-sterile conditions but with more ventilation. A Penicillium sp. isolated from litchi grew well in liquid medium acidified to the pH range reported for SO 2 and HCl-treated litchi fruits. Morphological analysis identified fungal isolates as P. aurantiogriseum. Internal transcribed spacer sequence analysis of five isolates suggested a sequence similarity to P. commune. Our data support the hypothesis that dipping litchi fruit in hydrochloric acid eliminates infection by common opportunistic fungi and selects for Penicillium species that tolerate low pH.