Postharvest quality of fresh-cut watercress: impact of non-thermal treatments based on inert-gas and ionizing radiation

Ready-to-eat vegetables are having a growing consumer acceptance for attending to contemporary requirements of convenience, safety and wholesomeness. The growth of this sector has led to the introduction of new food products and the implementation of more efficient and sustainable postharvest technologies1 In this sense, the suitability of modified atmosphere packaging (MAP) and post-packaging gamma irradiation for preserving quality parameters of fresh-cut watercress (Nasturtium officinale R. Br.) during cold storage was evaluated. Wild samples of watercress were rinsed in tap water and a portion was immediately analysed (fresh control). The remaining fresh material was packaged under nitrogen- and argon-enriched atmospheres, air (passive MAP) and vacuum. Air-packaged samples were then irradiated at doses up to 5 kGy in a cobalt-60 chamber. All packaged samples were stored at 4 oc for 7 days. The quality analyses included color, total soluble solids, pH, macronutrients, the individual profiles of sugars, organic acids, tocopherols and fatty acids, and total phenolics and flavonoids. Four in vitro assays based on different reaction mechanisms were also performed to evaluate the antioxidant capacity. After assessing the effect on the individual quality parameters, it was possible to conclude that argon-enriched atmospheres and the 2 kGy dose were suitable choices for preserving quality attributes of watercress during cold storage2 . However, samples irradiated at 5 kGy revealed chemical profiles more prone to exert positive health effects. Thereby, advantageous effects induced by modified atmospheres and ionizing radiation in the quality of fresh-cut watercress were highlighted, justifying the inclusion of this vegetable in human diets.