Margherita Modesti, Gianmarco Alfieri, Anna Magri, Roberto Forniti, Serena Ferri, Milena Petriccione, Isabella Taglieri, Fabio Mencarelli, Andrea Bellincontro
Department for Innovation of Biological, Agrofood and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy.
CREA - Research Centre for Olive, Fruit and Citrus Crops (CREA-OFA), Caserta, Italy.
Heliyon. 2024 Feb 8;10(4):e26067. doi: 10.1016/j.heliyon.2024.e26067. eCollection 2024 Feb 29.
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) 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.
对用于酿造红葡萄酒的葡萄进行多酚和花青素含量的定性评估。由于某些条件（天气、纬度、温度），这些化合物的浓度可能未达到酿造高品质葡萄酒所需的合适水平，因此采后技术可作为一种补救策略来应用。乙醇是一种次生挥发性代谢产物，其应用已被证明可延缓果实成熟、减少腐烂并增加次生代谢产物。本研究调查了采后施用乙醇对酿酒葡萄代谢和成分的影响。将酿酒葡萄（欧亚种葡萄品种阿利安尼科）暴露于不同剂量（0.25、0.5或1 mL/L）的乙醇中12、24或36小时。乙醇提高了糖浓度、苹果酸、游离氨基氮、多酚和花青素的含量。特别是，无论乙醇浓度如何，处理后的样品中花青素在12小时后就达到了平均1820 mg/L，而对照葡萄中的花青素含量为1200 mg/L。此外，最高浓度的乙醇改变了浆果的代谢，使其从有氧代谢转变为无氧代谢。所得结果表明，采后用乙醇处理12小时可能是提高酿酒葡萄中花青素含量的一个有趣解决方案，特别是当葡萄品质不如预期时。
