The limonene-derived mint aroma compounds in red wines. Recent advances on analytical, chemical aspects and sensory aspects

Regionality, frequently called terroir, is often used to market wines from different locations. Savatiano (Vitis Vinifera L.), is the dominant indigenous variety of the Mesogeia – Attiki region, reaching a percentage of 70% of the total vine cultivation, and being the most widely planted variety in Greece. In this context, this research focuses on the evaluation of the impact of different terroirs within the PGI Attiki zone on the aromatic profile of Savatiano.

Recently, foliar treatments with mineral-based compounds have shown positive effects on grapevine production by protecting grape from thermal excesses and reducing the decoupling between technological and phenolic maturity caused by climate change. Unraveling the effect of mineral particle applications on grape-associated microbes is pivotal for successful wine processing, due to the influence of the microbiota on wine composition and stability. To our knowledge, this is the first work that comprehensively studied the effects of kaolin and chabasite-rich zeolitites treatments on grape-related microorganisms (by real-time PCR quantification of total fungi, Hanseniospora uvarum, Metschnikowia pulcherrima, plant-associated bacteria and lactic acid bacteria), the expression of genes related to the flavonoid biosynthesis (PAL1, CHS1, F3H2, DFR, LDOX, UFGT, MYBA1, GST4, FLS4 genes) and the berry composition (°Brix, pH, acidity and anthocyanin concentrations) in cv. Sangiovese during ripening in two growing seasons (2019 and 2020).

The elaboration of sparkling wine is a demanding process requiring technical as well as scientific skills. Uncovering the role of the terroir to the final product quality is of great importance for the wine market. Although the impact of the yeast strains and their metabolites on the final product quality is well documented, the action of bacteria still remains unknown. The malolactic fermentation (MLF) is carried out by the lactic acid bacteria after the alcoholic fermentation in order to ensure the microbial stability during the second fermentation that takes place in the bottle or in tanks. Oenococcus oeni is the only selected species to drive MLF that has been commercialized for sparkling wine elaboration and it is naturally present on grapes, in the cellar and also in the final product. However, whether the bacterial strain contributes to the sensory characteristics of sparkling wine is still questioned.

Aged red wines possess phenolic composition very different from young ones due to the transformations among native grape phenolics and the formation of new polymeric polyphenols during aging process.

Grapevine physiology and production are challenged by forecasted increases in temperature and water deficits. Within this scenario, photoselective overhead shade films are promising tools in warm viticulture areas to overcome climate change related factors. The aim of this study was to evaluate the vulnerability of ‘Cabernet Sauvignon’ grape berry to solar radiation overexposure and optimize shade film use for berry integrity. A randomized complete block design field study was conducted across two years (2020-2021) in Oakville, Napa Valley, CA, with four shade films (D1, D3, D4, D5) differing in the percent of radiation spectra transmitted and compared to an uncovered control (C0). Integrals for gas exchange parameters and mid-day stem water potential were unaffected by the shade films in 2020 and 2021. By harvest, berries from uncovered and shaded vines did not differ in their size or primary metabolism in either year. Despite precipitation exclusion during the dormant season in the shaded treatments, yield did not differ between them and the control in either season. In 2020, total skin anthocyanins (mg/g fresh mass) in the shaded treatments was greater than C0 during berry ripening and at harvest. Conversely, flavonol concentrations in 2020 were reduced in shaded vines compared to C0. The 2020 growing season highlighted the impact of heat degradation on flavonoids. Flavonoid concentrations in 2021 increased until harvest while flavonoid degradation was apparent from veraison to harvest in 2020 across shaded and control vines. Wine analyses highlighted the importance of light spectra to modify wine composition. Wine color intensity, tonality and anthocyanin values were enhanced in D4 whereas antioxidant properties were enhanced in C0 and D5 wines. Altogether, our results highlighted the need of new approaches in warm viticulture areas given the impact that composition of light has on berry and wine quality.