The effect of Non-Thermal Plasma treatment on antioxidant molecules of different edible organs: two case studies on leafy vegetables and edible flowers

Non-Thermal Plasma (NTP) treatments have been proposed to improve crop yield and quality. NTP-treated water is indeed enriched in radical oxygen and nitrogen species and its application might influence the antioxidant molecule contents potentially improving the nutraceutical proprieties of treated plants. Despite the potentiality of this practice, the effect of NTP on real (i.e., commercial or semi-commercial) growing conditions has been poorly investigated. The NTP devices was used to treat crop canopy and root zone through the irrigation water on soilless cultures in a prototype greenhouse at CREA-OF in Pescia, Italy. The effect of NTP was evaluated on some antioxidant molecules in two varieties of Salanova® lettuce (green and red) and the edible flowers of two varieties of Begonia cucullata Willd. (white and red). The NTP treatment showed a positive effect on few antioxidant molecules, such as the anthocyanins in red lettuce and begonia flowers (Fig. 2) while it had a negative effect on other compounds, such as phenols and carotenoids in red lettuce and begonia flowers, respectively. The NTP treatment increased the chlorophylls of white and red begonia flowers while the same parameter was decreased in green and red lettuce. The NTP influence on the antioxidant molecules of food crops has been highlighted, but its effect depends on the plant species, edible organ, and variety. Further investigation regarding the timing and intensity of NTP treatment are needed.