Preliminary Results on the Effect of a Simultaneous CO2/Ethylene Treatment on Some Quality Properties of Persimmon Fruit

Kaki or Japanese persimmon is a high nutritional fruit. Italy is the main grower in the Mediterranean area, where all the native varieties are of astringent type needing to be treated in order to remove the astringency. Many methods exist for astringency removal, the most rapid is the treatment under CO2 at high concentration (90% or more) for 24-48 hours. Following the CO2 treatment, ethylene is used to ripen the fruits, however, there are little information on the practical requirements for treating persimmons fruit with ethylene. In this study authors show the results of a simultaneous CO2/ethylene gas treatment of persimmon, as opposed to the common sequential application of ethylene following CO2. The influence of both treatments on the fruit quality was evaluated in terms of weight loss (WL), color index (CI), firmness (FS), total soluble solids (TSS), tannins content (TC), juice titratable acidity (TA), immediately after the treatment, after 7 and 21 days to simulate the shelf life period (fruits were stored at 6°C and 85%-95% RH). Results show that, 1 d following the treatment, no differences in FS were found, by contrast CI and TA showed significant differences between all treatments. Results will be used to startup an innovative electrochemical ethylene sensor able to control the ethylene/CO2 gas mixture levels during the simultaneous treatment.