Department of Agricultural Sciences, Division of Vine and Wine Sciences, University of Naples Federico II, Avellino, Italy.
Division of Food Science and Technology, Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy.
J Sci Food Agric. 2025 Jan 15;105(1):123-131. doi: 10.1002/jsfa.13810. Epub 2024 Aug 12.
Postharvest dehydration affects the metabolism of grapes, impacting odorous secondary metabolites and therefore the features of the corresponding passito wines - high-quality products with winemaking practices linked to specific territories and related autochthonous grape varieties. Water loss and temperature conditions are the main variables of the dehydration process. This study assessed how they impacted the patterns of free and glycosylated volatile organic compounds (VOCs) of the exocarp (pulp) and epicarp (skin) in Nebbiolo and Aleatico, a neutral and semi-aromatic red grape variety, respectively. Dehydration parameters were set in tunnel conditions, and VOCs were quantitatively analyzed by solid phase extraction-gas chromatography-mass spectrometry.
For Nebbiolo grapes, weight loss had a greater impact on free volatiles than dehydration temperature, with a 20% weight loss increasing total VOCs in both exocarp and epicarp. Low temperature (10 °C) significantly increased (P < 0.05) the glycosylated VOCs' terpene content. In Aleatico grapes, weight loss was key in modulating free volatiles, with 30% weight loss and 15 °C leading to significant increases in VOCs, especially exocarp terpenes, acids and benzenoids. More stressful dehydration (30% weight loss at 25 °C) resulted in higher aroma precursor concentrations.
These findings can assist passito wine production in preserving varietal aromas of original grapes trough optimized dehydration conditions, preventing sensory homologation occurring because of strong uncontrolled dehydration. They can also promote optimization of energy consumption, thus fostering financial and environmental sustainability. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
采后脱水会影响葡萄的新陈代谢，影响有气味的次生代谢物，进而影响相应的风干葡萄酒的特征——这些高品质的葡萄酒采用与特定地域和相关本土葡萄品种相关的酿酒工艺酿造。水分损失和温度条件是脱水过程的主要变量。本研究评估了它们如何影响内果皮（果肉）和外果皮（果皮）中游离和糖苷化挥发性有机化合物（VOC）的模式在 Nebbiolo 和 Aleatico 葡萄中，分别是中性和半芳香红葡萄品种。在隧道条件下设置脱水参数，并通过固相萃取-气相色谱-质谱法对 VOC 进行定量分析。
对于 Nebbiolo 葡萄，失水对游离挥发物的影响大于脱水温度，20%的失水会增加内果皮和外果皮中总 VOC 的含量。低温（10°C）显著增加（P<0.05）糖苷化 VOC 萜烯含量。在 Aleatico 葡萄中，失水是调节游离挥发物的关键，30%的失水和 15°C 会导致 VOC 显著增加，尤其是内果皮萜烯、酸和苯类。更强烈的脱水（在 25°C 下损失 30%的水分）会导致更多的香气前体浓度增加。
这些发现可以通过优化脱水条件帮助风干葡萄酒生产保留原始葡萄的品种香气，防止因强烈的不受控制的脱水而导致感官同质化。它们还可以促进能源消耗的优化，从而促进财务和环境的可持续性。© 2024 作者。John Wiley & Sons Ltd 代表化学工业协会出版的《食品科学杂志》。
