From grapes to sparking wines: Aromas evaluation in a vine-spacing

Light is responsible for adverse reactions in wine including the formation of unpleasant flavors, loss of vitamins or photodegradation of anthocyanins. Among them, the riboflavin degradation leads to the formation of undesirable volatile compounds, known as light-struck taste. These photo-chemical reactions could be avoided by simply using opaque packaging. However, most rosé wines are kept in transparent bottles due to different commercial reasons. Some agri-food waste extracts have been studied for their photoprotective action which turn to be highly correlated with phenolic content [1].

Methoxypyrazines (MPs) are readily extracted from grape berry and rachis during fermentation and can impart “green” and “herbaceous” sensory attributes to wine. Irrespective of whether MPs, including 3-isobutyl-2-methoxypyrazine (IBMP), 3-isopropyl-2-methoxypyrazine (IPMP), and 3-sec-butyl-2-methoxypyrazine (SBMP), are extracted from berry or other vine material, techniques for remediation of wine with overpowering sensory characters attributable to MPs suffer from poor specificity or produce undesirable sensory outcomes, meaning that alternative control approaches are needed.

Schiava cv. (germ. Vernatsch) is a group of grape varieties used for winemaking (e.g. Kleinvernatsch-Schiava gentile, Grauvernatsch-Schiava grigia, Edelvernatsch-Schiava grossa) historically reported in Northern Italy, Austria, Germany and Croatia. Beside common phenotypic traits, these varieties have been also hypothesized to share a common geographical origin in Slavonia (Eastern Croatia). Nowadays, Schiava cv. are considered historical grape varieties of northern regions of Italy such as Lombardy, Trentino and South Tyrol. Traditionally widely consumed locally and also exported, over the past decades there has been a steady drop in production of these grapes, although with a parallel increase in wine quality. In this report, the effects of three main enological variables on the chemical components of Schiava produced in South Tyrol (var. Schiava grossa) are investigated from grape to bottle.

Many farming operations aim at controlling the leaf area of the vine according to its load. There are several techniques, direct and indirect, of estimate of this leaf area in a specific way, but impossible to implement at great scales. These last years, research in airborne and satellite remote sensing made it possible to show that a multispectral index of vegetation, computed from measurements of reflectances (red and near infrared), the « Normalised Difference Vegetation Index » (NDVI), is well correlated to the « Leaf Area Index » (leaf area per unit of ground) of the vine. Nevertheless these methods of acquisition and processing data are rather constraining and complex.

In this audio recording of the IVES science meeting 2022, Gonzaga Santesteban (Department of Agronomy, Biotechnology and Food Science, Public University of Navarra (UPNA), Pamplona, Navarra, Spain) speaks about cover crops in viticulture. This presentation is based on 2 original articles accessible for free on OENO One.