Effect of nitrogen fertilizer level on quality and shelf-life of fresh cut Swiss chard

Swiss chard (Beta vulgaris L. var. cicla L.) is a leafy vegetable highly appreciated in some areas for its nutritional properties and year round supply. Its production area is not commercially important, but this minor vegetable offers an interesting enlargement of the current vegetable assortment by using its stalks and leaves. Swiss chard is a very nutritive demanding species. The content of mineral elements, total quality and yield are influenced by the amount, frequency and method of fertilization. The aim of this study was to evaluate the effect of high or low levels of nitrogen fertilization on the quality and shelf-life of minimally processed Swiss chard. Plants grown with a high (180 kg ha-1) or low (60 kg ha-1) level of nitrogen fertilizer were harvested and then immediately processed as fresh-cut produce. Leaves were stored in PE bags at 5°C for 14 days. On day 0, 7 and 14, the fresh and dry matter, colour, SSC, nitrate, ascorbic acid and chlorophyll were evaluated. After 2 weeks of cold storage, minimally processed Swiss chard showed good quality. Higher levels of nitrates and ascorbic acid were found in the leaves from plants grown with a higher level of nitrogen fertilization.