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This PhD thesis aimed to clarify the effects due to different ozone postharvest treatments on quality traits and accumulation of phenolic healthy compounds in white wine grapes, belonging to Grechetto cv. The thesis also aimed to investigate whether and how the ozone treatments could affect the flavor profile of the grapes. Finally, it aimed to apply one of the most used chemometric tools, the principal component analysis (PCA), to gain insights into variations in the nutritional profiles between different postharvest treatments trying to classify them on the basis of some molecular markers of oxidative state. Grapes were exposed to ozone gas in air (GO) or in nitrogen atmosphere (GNO) for 12 hours at 10°C and then kept in normal atmosphere for one day at room temperature. Grapes kept at 10°C, for 12 hours without ozone treatment plus one day at room temperature, were considered as the control sample (GC). Results showed that low temperature induced a great change of ripening features only in GC with reduction of weight, loss of sugars (about 20%) and increase in titratable acidity but, above all, 15% of increase in malondialdehyde (MDA). The use of ozone in air or in nitrogen neither altered the fruit quality attributes nor modified MDA concentration. Ozone provoked a high decrease of hydroxycinnamic acids, compared to the harvest grapes, overall in GNO samples (caftaric acid:-38.8%; coutaric acid:-26.1%). Besides, cold storage treatment without ozone enhanced the antiradical capacity of grapes. Three main flavonols, named hyperoside (quercetin-3-O-galactoside), rutin

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