Using ethanol as postharvest treatment to increase polyphenols and anthocyanins in wine grape
Modesti Margherita,
Alfieri Gianmarco,
Magri Anna,
Forniti Roberto,
Ferri Serena,
Petriccione Milena,
Taglieri Isabella,
Mencarelli Fabio,
Bellincontro Andrea
Affiliations
Modesti Margherita
Department for Innovation of Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
Alfieri Gianmarco
Department for Innovation of Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
Magri Anna
CREA - Research Centre for Olive, Fruit and Citrus Crops (CREA-OFA), Caserta, Italy; Department of Environmental, Biological and Pharmaceutical Sciences and Technologies (DiSTABiF), University of Campania Luigi Vanvitelli, Caserta, Italy
Forniti Roberto
Department for Innovation of Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
Ferri Serena
Department for Innovation of Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy
Petriccione Milena
CREA - Research Centre for Olive, Fruit and Citrus Crops (CREA-OFA), Caserta, Italy
Taglieri Isabella
Department of Agriculture Food and Environment (DAFE), University of Pisa, Pisa, Italy
Mencarelli Fabio
Department of Agriculture Food and Environment (DAFE), University of Pisa, Pisa, Italy
Bellincontro Andrea
Department for Innovation of Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy; Corresponding author. DIBAF, Via San Camillo de Lellis snc 01100 Viterbo (VT) Italy.
Red wine grapes are qualitatively evaluated for their content in polyphenols and anthocyanins. Due to certain conditions (weather, latitude, temperature), the concentration of these compounds may be not at the right level for reaching a high-quality wine, thus postharvest technologies can be operated as a remediation strategy. Ethanol is a secondary volatile metabolite and its application has been demonstrated to delay fruit ripening, to reduce decay, and to increase secondary metabolites. The present study investigates the effects of ethanol post-harvest application on wine grapes’ metabolism and composition. Red wine grapes (Vitis Vinifera L. cv Aglianico) were exposed to different ethanol doses (0.25, 0.5, or 1 mL L−1) for 12, 24, or 36 h. Ethanol increased sugar concentration, malic acid, free amino nitrogen, polyphenols, and anthocyanins. Particularly, anthocyanins reached an average value of 1820 mg/L in treated samples versus the 1200 mg/L of control grapes already after 12 h whatever the concentration was. Moreover, the highest concentration of ethanol modified berry metabolism shifting from aerobic to anaerobic one. Obtained results suggest that 12 h of ethanol postharvest treatment could be an interesting solution to improve anthocyanins in wine grapes, especially when the quality is not as good as expected.
