Glutathione and other sulphur metabolite changes into Brassica rapa l. cv. sylvestris during postharvest storage

Biotic and abiotic stresses results in an increased reactive oxygen species production (oxidative stress) that can cause changes of metabolism until to cell death. Glutathione appears as the major thiol compound involved in the control of oxidative stress and has been involved in the prevention of age- related degenerative diseases. Glutathione occurs mainly in leafy vegetables that have an important role in the Mediterranean diet. Leafy vegetables, due to cutting and manipulation processes at the harvest, apart the stop of the water, nutrient and hormone flow, suffer an oxidative stress that activate repair or senescence processes. In this study glutathione and other sulfur metabolites were determined during postharvest storage in an ecotype of Brassica rapa L cv. Sylvestris. An innovate pre-column monobromobimane based derivatization of the sulphur compounds producing highly fluorescent and stable compounds was developed. Their separation and quantification was performed by fluorimeter equipped HPLC. The results were analyzed and discussed. The work was financially supported by "Seconda Università degli Studi di Napoli" and "MIUR"•(PRIN2006077008_005;2008S9T3KK_003).