Department of Agriculture, Food and Environment (DAFE), University of Pisa, Pisa, Italy.
Council for Agricultural Research and Economics (CREA) - Research Centre for Olive, Fruit and Citrus Crops, Caserta, Italy.
J Sci Food Agric. 2024 Feb;104(3):1591-1598. doi: 10.1002/jsfa.13042. Epub 2023 Oct 25.
During postharvest dehydration, grapes are subject to metabolic changes including ethanol anabolism and catabolism. These changes affect the quality of the final product and ethanol production is a key step. Ethanol dissipation has never been measured during postharvest wine grape dehydration. Thus, the present study aimed to: (i) monitor ethanol dissipation and (ii) investigate chemical-biochemical changes in berries during dehydration.
Ethanol dissipation from Raboso grapes, under controlled postharvest dehydration, was found to comprise up to 36% of weight loss (w.l.). Moreover, the activity of enzymes involved in the anaerobic metabolism of grapes was investigated. Ethanol dissipation was highly correlated with grape weight loss (r = 0.989). Alcohol dehydrogenase activity, responsible for the reduction of ethanol to acetaldehyde, declined significantly with w.l. Similarly, pyruvate decarboxylase and lactate dehydrogenase reduced their activity. High lipoxygenase activity was measured at 27% w.l., whereas polyphenol oxidation was constant and declined in the last sampling.
Ethanol dissipation during postharvest dehydration allows for reducing anaerobic metabolism and promotes oxidative metabolism. The sensor used can be a useful commercial tool for monitoring berry metabolism. © 2023 Society of Chemical Industry.
在采后脱水过程中，葡萄会经历包括乙醇合成和分解代谢在内的代谢变化。这些变化会影响最终产品的质量，而乙醇生产是一个关键步骤。然而，在采后酿酒葡萄脱水过程中，从未测量过乙醇的消散。因此，本研究旨在：（i）监测乙醇的消散；（ii）研究浆果在脱水过程中的化学-生物化学变化。
在控制采后脱水的条件下，拉博索葡萄的乙醇消散量占葡萄失重的 36%。此外，还研究了参与葡萄无氧代谢的酶的活性。乙醇消散与葡萄失重高度相关（r=0.989）。负责将乙醇还原为乙醛的醇脱氢酶活性随失重显著下降。同样，丙酮酸脱羧酶和乳酸脱氢酶的活性也降低了。在 27%的失重时，检测到较高的脂氧合酶活性，而多酚氧化则保持不变，在最后一次采样时下降。
采后脱水过程中的乙醇消散可以减少无氧代谢，促进氧化代谢。所使用的传感器可以成为监测浆果代谢的有用商业工具。 © 2023 化学工业协会。
