Non-Saccharomyces yeasts, particularly Metschnikowia pulcherrima, are considered alternatives to SO₂ in winemaking, combating specific microorganisms. The sensory profile of the wine is contingent upon the type of yeast, the fermentation conditions, and the concentration and mode of application with Saccharomyces cerevisiae strains (whether pure or used in mixed/sequential co-fermentation). This study assessed the aroma in red wines produced with S. cerevisiae (Sc) and M. pulcherrima (Mp, non-Sc), incorporating variations in the method of addition and the inclusion or exclusion of SO₂. The enological parameters of the wines were slightly affected. Volatile compounds were analysed in the wines through gas chromatography–mass spectrometry (GC-MS) at three moments: at the end of malolactic fermentation (MLF) and after 6 and 9 months of bottle ageing. Sequential fermentation of Sc and Mp reduced the concentration of most identified alcohols and acids, which is favourable, as these compounds can yield undesirable aromas at high concentrations. Regardless of the yeast mixture and Mp dose, a majority of the acetate esters and ethyl esters were quantified at concentrations above their perception thresholds, thus enhancing the sensory quality of the wines. Sensory analysis of wines showed generally positive evaluations. Using non-Saccharomyces as an alternative to SO₂ improves the aromatic profile of wines.

Foliar nutrient sprays are broadly used in commercial agriculture. To date, the application of Ca and Si has been little explored in vineyard production but may lead to positive responses at various levels. Therefore, the aim of this work was to evaluate the effect of supplying single or combined calcium (Ca, 120 mM) and silicon (Si, 120 mM) sprays in Tempranillo grape composition. Foliar treatment with Ca + Si foliar enhanced all families of aromatic compounds, whereas single Ca and Si sprays induced lower effects. Regarding phenolic compounds, all foliar treatments led to minor effects. However, all three foliar Ca and Si treatments increased the total grape amino acid content. Consequently, the application of combined Ca and Si sprays to a vineyard is recommended as a tool for improving grape quality.

Methyl jasmonate (MeJ) is an elicitor that, when applied in the vineyard, can improve grape quality. There are several studies about the MeJ influence on red grape varieties; however, to our knowledge, there is little information about white grape varieties, specifically Tempranillo Blanco. Therefore, the aim of this work is to evaluate the effect of MeJ foliar treatments, carried out at veraison and post-veraison, on the aromatic, phenolic and nitrogen composition of Tempranillo Blanco grapes. The results showed that grape volatile compounds content increased after MeJ application, especially terpenoids, C₁₃ norisoprenoids, benzenoids and alcohols, and, in general, mainly at post-veraison. Regarding phenolic and nitrogen compounds, their concentrations were enhanced after MeJ treatments, regardless of application time. Consequently, MeJ treatment improved grape volatile, phenolic and nitrogen composition, particularly when this elicitor was applied post-veraison. Therefore, this is a good and easy tool to modulate white grape quality.

BACKGROUND: Viticulture has adapted foliar applications of biostimulants as a tool to improve crop quality. Recently, nanotechnology has been incorporated as a strategy to reduce the loss of biostimulants and treat nutrient deficiencies. Therefore, the present study aimed to investigate the effect of foliar applications of amorphous calcium phosphate nanoparticles (ACP) doped with methyl jasmonate (ACP‐MeJA) and urea (ACP‐Ur), individually or together (ACP‐MeJA+Ur), on the content of volatile compounds in ‘Tempranillo’ grapes, compared to the conventional application of MeJA and Ur, individually or in combination (MeJA+Ur).RESULTS: The results showed that nanoparticle treatments reduced the total C6 compounds and some carbonyl compounds in the grape musts. This is of novel interest because their presence at high levels is undesirable to quality. In addition, some aroma‐positive compounds such as nerol, neral, geranyl acetone, β‐cyclocitral, β‐ionone, 2‐phenylethanal and 2‐phenylethanol increased, despite applying MeJA and Ur at a lower dose.CONCLUSION: Consequently, although few differences in grape volatile composition were detected, nanotechnology could be an option for improving the aromatic quality of grapes, at the same time as reducing the required doses of biostimulants and generating more sustainable agricultural practices. © 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.