Hot water dipping treatments on Tarocco orange fruit and thier effects on peel essential oil

The most common and serious diseases which affect citrus fruit after harvest in Italy are induced byPenicillium digitatum Sacc. and Penicillium italicum Weh., responsible respectively for green and bluemold rots. This paper deals with the effectiveness of hot water dipping (HWD) treatments as alternativemeans to control postharvest decay on Tarocco orange fruit [Citrus sinensis (L.) Osbeck], and their effecton fruit quality with special regard to peel essential oils. Selected treatments were HWD at 52oC for 180 sand at 56oC for 20 s. These treatments were compared with an effective fungicide standard treatment(Imazalil) and an untreated control. The results showed that HWD at 56oC for 20 s was more effective ininhibiting P. digitatum spore germination than HWD at 52oC for longer exposure time. In addition, HWDtreatment at 56oC significantly increased the level of alcohols, esters and aliphatic (fatty) aldehydes.Therefore, the lowest values of decay incidence recorded in HWD fruit treated at 56oC may be due tothe increase in oxygenated monoterpenes, esters and aldehydes. Finally, HWD treatments did not causesurface damage or color change and did not influence internal quality parameters.