Quality attributes of fresh-cut lettuce treated with cold plasma

Cold plasma is a novel method that has proved to be capable as a sanitizing process due to its antimicrobial effects. This study aims to highlight the optimization of this technique for maintaining freshness and safety of fresh-cut lettuce without using any other chemical preservatives. The used atmospheric pressure plasma jet is driven by a radio frequency generator (27.12 MHz) with argon as working gas. The jet has been used at different operating powers in order to evaluate the optimal process parameters that do not affect the product quality. The quality of the lettuce leaves was assessed by optical methods such as chlorophyll fluorescence imaging analysis, fluorescence spectroscopy and colour measurement before and after plasma treatment, and also during the storage period. Depending on the applied process parameters, the effects of the cold plasma treatment on the quality of lettuce leaves can be controlled. However, the treatment conditions have to be adapted to each type of commodity.