*4.2. Preliminary Test*

A preliminary experimental set-up has been conducted in order to determine the possible phytotoxicity or negative effects of the EP on the examined produce quality. Tomatoes were placed in 1 L capacity polystyrene (2 fruits per container), snap-on lid containers.

A total of five concentrations of the EP were examined (0.05%–0.1%–0.2%–0.4%–0.8% *v*/*v*), while purified water (0.0% EP) was used as control treatment and applied either as vapor or dipping. Three replications were used for each concentration and for each application. Containers were placed in a chamber at 11 ◦C and 90% relatively humidity (RH), in the dark. To maintain high RH during storage period, wet filter paper was displaced inside each container, and was remoistened every second day [46]. Container lids were open every 48 h and aerated in order to avoid air composition abnormalities (i.e., decreased O2 and increased CO2 levels). Fresh produce was monitored for phytotoxicity (marked spots), marketability, aroma and weight loss (as described at the main experiment) after 2 days of storage. Based on the results, the concertation of 0.4% was selected for further investigation and it was compared with a double level of the eco-product (0.8% EP) and common postharvest sanitizer (i.e., chlorine) in vapor or dipping applications.
