Extension of Tomato Shelf Life via Nitric Oxide Treatment Using Air Plasma

Abstract Nitric oxide (NO) generation-enhanced atmospheric-pressure plasma technology has been investigated as a nonthermal intervention technology for prolonging the ripening period of tomatoes. UV-irradiated dielectric barrier discharge plasma reaches the NO-enhanced mode earlier, and NO is rapidly involved in the inhibition of tomato respiration. With as little as 26 W of power in total, the NO-processing of tomatoes using plasma technology helps control the postripening of tomatoes. The NO-enrichment mechanism was analyzed through numerical calculations, which revealed that the photolysis of ozone (O3) and nitrous acid (HONO) occurred during UV irradiation. The measured amount of CO2 emitted from plasma-treated tomatoes was ~ 300 ppm lower than that emitted from nontreated tomatoes, indicating that metabolism and respiration were inhibited. In addition, the NO-enhanced plasma treatment of tomatoes is considered to be more effective because the so-treated tomatoes emitted 100 ppm less CO2 than the plasma-treated tomatoes. The delay of respiration through plasma treatment can help prevent color changes or decreases in the firmness of tomatoes.