IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Study of grape-ripening process variability using mid infrared spectroscopy

Study of grape-ripening process variability using mid infrared spectroscopy

Abstract

To obtain a quality wine, it is necessary to collect grapes in an optimal state of maturation, so the control of the ripening process is fundamental for the viticulturist. During this process, the grapes suffer different physiological and chemical changes that include berry softening, sugar accumulation and metabolism of different chemical compounds such as organic acids, polyphenols or aromatic compounds. As these changes occur within each berry, the same bunch may contain berries at different stages of maturity, making it difficult to determine a single optimal state. In addition, when the position of the bunch on the vine and the position of the vine within the vineyard are also considered, the difficulty to correctly determine the optimum ripening point becomes even greater. To solve this problem, a representative sampling of the vineyard is usually made and the average values of sugar contents, acidity (pH or titratable acidity) and phenolic compounds (mainly in red varieties) are determined towards the designation of harvest time.

The classical analytical methods used to determine these parameters are destructive, time consuming and cannot be applied on-site. Recent developments in equipment, such as infrared spectroscopy, hyperspectral imaging or specific sensors (i.e. DA-meter) allow obtaining real-time information about the maturity of the grapes. In this work, a strategy
consisting on coupling FTIR-ATR spectroscopy and chemometric tools is proposed for an effective ripening control, which implies knowing the real state of maturation of the berries and not a single average value. This information will make it possible to carry out the suitable viticultural practices to improve the quality of the grapes.

ANOVA-simultaneous component analysis (ASCA) was applied to factorize the ripening variability sources, such as the bunch-height in the plant or the grape-position in the bunch. The variability sources affecting the MIR spectra and the sugar content and pH were studied, showing an evolution over time and depending on the position of the berries. Moreover, prediction of sugar content and pH was achieved by measuring the grapes in the vineyard, showing the capability of the FTIR portable device to monitor the ripening process.

DOI:

Publication date: June 23, 2022

Issue: IVAS 2022

Type: Article

Authors

Schorn-Garcia Daniel¹, Giussani Barbara², Busto Olga¹, Aceña Laura¹, Boqué Ricard¹ and Mestres Montserrat¹

¹Universitat Rovira i Virgili, Department of Analytical Chemistry and Organic Chemistry, Instrumental Sensometry (iSens)
²Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell’Insubria

Contact the author

Keywords

grape-ripening process, FTIR, portable device, ASCA

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Multi-omics methods to unravel microbial diversity in fermentation of Riesling wines

Wine aroma is shaped by the wine’s chemical compositions, in which both grape constituents and microbes play crucial roles. Although wine quality is influenced by the microbial communities, less is known about their population interactions.

Read More

Effect of foliar application of urea and nano-urea on the cell wall of Monastrell grape skins

The foliar application of urea has been shown to be able to satisfy the specific nutritional needs of the vine as well as to increase the nitrogen composition of the must. On the other hand, the use of nanotechnology could be of great interest in viticulture as it would help to slow down the release of urea and protect it against possible degradation. Several studies indicate that cell wall synthesis and remodeling are affected by nitrogen availability.

Read More

Climate change and viticulture in Nordic Countries and the Helsinki area

The first vineyards in Northern Europe were in Denmark in the 15th century, in the southern parts of Sweden and Finland in the 18th century at 55–60 degrees latitude. The grapes grown there have not been made into wine, but the grapes have been eaten at festive tables. The resurgence of viticulture has started with global warming, and currently the total area of viticulture in the Nordic countries, including Norway, is estimated to be 400–500 hectares, most of which is in Denmark. Southern Finland, like all southern parts of Northern Europe, belongs to the cool-cold winegrowing area.

Read More

Volatile composition of base wines to obtain sparkling wines from seven autochthonous grape varieties from Castilla y León (Spain)

The aim of this work was to characterize the aromatic profile of white and rosé base wines for the elaboration of sparkling wines from seven autochthonous grape varieties of Castilla y León. The ‘Albarín’, ‘Godello’ and ‘Verdejo’ white grape cultivars contribute with more fruity notes than the ‘Viura’ and ‘Malvasía’ cultivars; and ‘Prieto picudo’ coloured grape cultivar has more fruity character than ‘Garnacha’.

Read More

Rapid optical method for tannins estimation in red wines

In this work, an innovative analytical method has been proposed for fast and reliable in-line analysis of tannins in wines; the method is fast, does not require sample preparation and is based on the selective reactivity of tannins in a mixture containing proteinaceous matter (i.e. gelatin), under pH 3.5, resulting in the formation of white cloudiness.

Read More