The Australian Wine Research Institute, P.O. Box 197, Glen Osmond, SA 5064, Australia.
Molecules. 2021 Aug 27;26(17):5197. doi: 10.3390/molecules26175197.
Due to the increasing frequency of wildfires in recent years, there is a strong need for developing mitigation strategies to manage the impact of smoke exposure of vines and occurrence of 'smoke taint' in wine. One plausible approach would be to prevent or inhibit the uptake of volatile phenols from smoke into grape berries in the vineyard. In this study we describe a model system we developed for evaluating under controlled conditions the effectiveness of a range of surface coatings (including existing horticultural sprays) for reducing/preventing the uptake of volatile phenols and their subsequent conversion to phenolic glycosides. Grapes were coated with the materials to be tested and then exposed to gaseous phenols, via evaporation from an aqueous solution, in a semi-closed glass container. Analysis of volatile phenols and their glycosidic grape metabolites demonstrated that the treatments typically did not provide any significant protection; in fact, some resulted in higher concentrations of these compounds in the grapes. The highest concentrations of volatile phenols and their glycosides were observed after application of oily, hydrophobic materials, suggesting that these materials may enhance the adsorption or transfer of volatile phenols into grape berries. Therefore, it is important to consider the types of sprays that are being applied in the vineyard before and during smoke events to prevent the potential of exacerbating the uptake of smoke compounds by grape berries.
由于近年来野火的频率不断增加，因此强烈需要制定缓解策略来管理烟雾暴露对葡萄藤的影响和葡萄酒中“烟雾异味”的发生。一种可行的方法是防止或抑制挥发性酚类物质从烟雾中被吸收到葡萄园里的葡萄浆果中。在这项研究中，我们描述了一个模型系统，用于在受控条件下评估一系列表面涂层（包括现有的园艺喷雾剂）在减少/预防挥发性酚类物质及其随后转化为酚糖苷方面的有效性。将待测试的材料涂覆在葡萄上，然后将其在半封闭的玻璃容器中通过从水溶液中蒸发来暴露于气态酚类物质。对挥发性酚类物质及其糖苷类葡萄代谢物的分析表明，这些处理通常不能提供任何显著的保护；实际上，一些处理导致葡萄中这些化合物的浓度更高。在应用油性疏水性材料后，观察到挥发性酚类物质及其糖苷的浓度最高，这表明这些材料可能会增强挥发性酚类物质向葡萄浆果中的吸附或转移。因此，在烟雾事件发生之前和期间，在葡萄园里应用的喷雾类型是非常重要的，以防止潜在地加剧葡萄浆果对烟雾化合物的吸收。
