Effects of ethanol, acetaldehyde and ethyl formate vapour on the growth of<i>Penicillium italicum</i>and<i>P. digitatum</i>on oranges

SummaryEthanol (Etoh) (C2H5OH), acetaldehyde (Aa) (CH3CHO) and ethyl formate (EF) (CHO2C2H5) are naturally occurring volatiles reported to have either anti-microbial or insecticidal properties. The effect of these volatiles on the spoilage of oranges by Penicillium italicum and P. digitatum at 20°C was evaluated. Ethanol was the most effective and the least phytotoxic volatile in retarding the establishment of infection and the rate of microbial development of P. italicum and P. digitatum. Overall, P. digitatum was more resistant to the antifungal effect of Etoh and Aa than P. italicum. Ethyl formate was relatively ineffective against both pathogens. The effectiveness of the volatiles was dependent upon concentration and exposure time.