Ozone treatments potentially allow to increase some wine grape compounds

Ozone is a natural, strong oxidant which has great toxicity for plants but when used as postharvest fumigation can? have significant sanification activity but also interesting metabolic effect. In this study, the effect of ozone on volatile organic compounds (VOCs), on cell wall and on polyphenols content have been studied based on a patent pending technology (EU 12704901.3-1357). Different wine grape varieties have been tested. On ?Sauvignon Blanc?, postharvest ozone treatment increased the glycosilated volatiles organic compounds, overall benzyl alcohol, methoxyeugenol, coniferol 2, 7-OH ?-terpineol and isogeraniol. In ?Cabernet Sauvignon? grapes harvested at different maturity stages, ozone postharvest treatment induced higher activity of cell wall enzymes activity, especially during dehydration and cell wall composition was modified by a release of neutral sugars and a decrease of cellulose and uronic acids content. Significant differences have been found on phenolic content. Some fraction as cinnamates and flavonols resulted to be positively affected by the treatment, whereas catechin and epicatechin was found to be more susceptible to ozone degradation. Anthocyanins are resulted to be less? sensitive to the ozone treatment, indeed, an increase was shown on unripe grape exposed to medium ozone concentration, while others samples remained quite stable after the exposure. SourcesMetabolic and structural effects of dehydration and ozone postharvest treatments on wine grapesF. De Sanctis1, J. Labatvich2, J.A. Kennedy3, C. Catelli4, F. Mencarelli11University of Tuscia, Via DeLellis, 01100 Viterbo, Italy2Department of Plant Science, Univesrity of California at Davis, One Shields Ave, 95616 Davis, USA3Department of Viticulture and Enology, CSU, 2360 East Barstow Ave, MS VR89, Fresno, CA 93740-8003, USA4PC Eng, Via Roma 81, 22029 Uggiate Trevano (CO), ItalyV Postharvest Unlimited, ISHS International Conference, 10-13 June 2014, Cyprus, http://web.cut.ac.cy/postharvest/Picture by osteoartritis.wordpress.com