Kaolin protective effect was assessed in a white grapevine cultivar ‘Cerceal’ in ‘Alentejo’ Region (southeast Portugal) where plants face extreme conditions during the summer season. We addressed the hypothesis that kaolin effects lead to several changes in leaves, fruits, and wine characteristics on the primary and secondary metabolism. Results showed that kaolin reduces leaf temperature which provokes an improvement in physiological parameters such as net photosynthesis and water use efficiency. This protection interferes with berry color, leaving them more yellowish, and an increase in phenolic compounds were observed in all fruit tissues (skin, seed, and pulp). Additionally, both berry and wine characteristics were strongly affected, with an increase of tartaric and malic acid and consequently high total acidity, while the sugar concentration decreased 8.9% in berries provoking a low wine alcohol level. Results also showed that kaolin induces high potassium, magnesium, and iron, and low copper and aluminum concentrations. Moreover, the control wine showed higher content of esters related with hostile notes whereas wine from kaolin treated vines presented higher content of esters associated with fruity notes. Overall, the results strengthen the promising nature of kaolin application as a summer stress mitigation strategy protecting grapevine plants and improving fruit quality and creating more balanced wines.

中文翻译：

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从葡萄到葡萄酒的高岭土效果概述：宫颈白变种案例研究

在“ Alentejo”地区（东南葡萄牙）的白色葡萄品种“ Cerceal”中评估了高岭土的保护作用，该地区的植物在夏季处于极端条件。我们提出了一个假设，即高岭土作用导致主要代谢和次生代谢中的叶片，果实和葡萄酒特性发生若干变化。结果表明，高岭土降低了叶片温度，从而提高了生理参数，例如净光合作用和水分利用效率。这种保护作用会干扰浆果的颜色，使它们变黄，并且在所有水果组织（皮肤，种子和果肉）中都观察到酚类化合物的增加。此外，浆果和葡萄酒的特性均受到严重影响，酒石酸和苹果酸增加，因此总酸度高，而浆果中的糖浓度降低了8.9％，导致葡萄酒的酒精含量较低。结果还表明，高岭土诱导高钾，镁和铁，以及低铜和铝浓度。此外，对照葡萄酒显示出与敌对味相关的酯的较高含量，而来自高岭土处理过的葡萄藤的葡萄酒显示出与果味相关的酯的较高含量。总的来说，这些结果增强了高岭土应用的前景，将其作为夏季缓解应力的策略来保护葡萄植物并改善果实品质并创造出更加平衡的葡萄酒。对照酒显示出与敌对味相关的酯含量更高，而高岭土处理过的葡萄藤的酒与果味相关的酯含量更高。总的来说，这些结果增强了高岭土应用的前景，将其作为夏季缓解应力的策略来保护葡萄植物并改善果实品质并创造出更加平衡的葡萄酒。对照酒显示出与敌对味相关的酯含量更高，而高岭土处理过的葡萄藤的酒与果味相关的酯含量更高。总的来说，这些结果增强了高岭土应用的前景，将其作为夏季缓解应力的策略来保护葡萄植物并改善果实品质并创造出更加平衡的葡萄酒。