Prediction of astringency in red wine using tribology approach to study in-mouth perception

Global warming is accelerating grape ripening, leading to unbalanced wines from fruit with high sugar content but poor aroma and colour development. Reducing the size of the photosynthetic apparatus after veraison has been shown to delay technological ripeness in cool climates, but methods have not been tested in areas with high irradiance and temperature where fruit exposure could have disastrous effects on berry composition. In this Cabernet-Sauvignon trial, we compared the application of an antitranspirant (pinolene), to severe canopy topping and above bunch zone leaf removal, all performed at mid-ripening, with an untouched control. We monitored the vines weekly by measuring stem water potential, gas exchange, fruit zone light exposure. We sampled berries to measure berry weight, total soluble solids, pH, titratable acidity, and the anthocyanin profile. At harvest, we assessed yield components, measured carbon isotope discrimination, rated sunburn on clusters, and produced experimental wines. We submitted harvest samples to metabolomic profiling through PFP-Q Exactive MS/MS and wines to sensory analysis. Application of the antitranspirant significantly reduced stomatal conductance and assimilation rate but did not affect the stem water potential. Inversely, leaf removal and topping increased water potential but did not affect leaf gas exchange. The late topping was the only treatment able to decrease sugar content (up to 2Bx), increase titratable acidity and pH, and improve anthocyanin content because of lower degradation of di-hydroxylated forms. Late leaf removal above the bunch zone increased lightning conditions in the canopy and produced the most significant damage on fruits. Yield components were not affected. This work suggests that late-season canopy management can effectively control ripening speeds and improve grapes and wines. Still, the effect on grape exposure in a critical time must be well balanced to avoid problems with the appropriate technique.

In recent years, the consumption of alcoholic beverages is changing, driven by evolving consumer preferences and societal trends, including a wave of health consciousness. Among these changes, the emergence and proliferation of nolo (no alcohol/low alcohol) alcoholic beverages have gained significant attention within the industry. Nolo alcohol beverages are produced to emulate the appearance, aroma, and taste of alcoholic beverages, potentially facilitating a sense of social integration when consuming a product that closely resembles alcohol.

The grapevine is facing significant challenges due to climate change, as rising temperatures impact its physiological traits and disrupt plant phenology.

Viticulture worldwide is currently affected by the effects of climate change. This set of adverse phenomena lead to a deterioration of functional vine mechanisms, affecting growth, physiology and grape ripening, which may cause severe losses with respect to yield and quality. To prevent water stress and other abiotic factors from severely affecting its physiology, the vine’s response is to reduce transpiration and photosynthesis rates. This response varies depending on the cultivar and its ability to adapt to the environment. The hydroscape method is based on the internal regulation of water status in the plant. It has been recently used to classify grapevine genotypes according to their iso/anisohydric behavior when they are subjected to water stress conditions.

Brazil is one of the few countries where vineyards of Vitis labrusca and Vitis vinifera coexist in the same geographical spaces, due to complex processes of territorial occupation by successive waves of European settlers.