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…

The influence of site aspect and pruning types on Pinot Noir phenology and shoot growth

Aim: Managing the influence that terroir in vineyards has on vine development depends on improving our understanding the effect of the interaction of within-site variability, within-vine variability, and management practices (such as pruning types) on phenology and vine development. This study evaluates the consequence of site aspect

Read More

Viñedos de la D.O. Ribeira Sacra: heterogeneidad varietal y sanitaria

La D.O. Ribeira Sacra (Galicia, N.O. de España) se distribuye a lo largo de las riberas de los ríos Miño y Sil. Su característica mas destacada son las fuertes pendientes. Desde 1990 se estudia el estado

Read More

Recent advances in our understanding of the impact of climate change on wine grape production

According to the last IPCC report, the scale of recent climate changes are unprecedented over many centuries. Each of the last four decades has been successively warmer than any decade since 1850. Projections for the future foresee that temperature could reach +3.3°C to +5.7°C under the most pessimistic scenario. It is also projected that every region will face more concurrent and multiple changes in climatic impact-drivers. The frequency of extreme climate events is also likely to increase, as well as the occurrence of indirect constraints. These evolving climatic conditions are alrealdy affecting and will continue to affect the suitability of traditional wine grape production areas, but also create opportunities in new locations.

Read More

Oenological potential of wines and agronomical characterisation of grapes from five white resistant Italian varieties at Serra Gaúcha, Southern Brazil

Rio grande do sul is the main grape producing state in Brazil, with the largest wine-growing area, responsible by 90% of the national production of wines and grape juices. Serra Gaúcha is the main vitivinicultural region, where around 15% of the area is destined to produce wines from vitis vinifera L. grapes. This region presents high rainfall during the grape maturation cycle, a factor that leads to great risk of attacks by fungal pathogens. the use of resistant varieties can reduce the cost and quantity of spraying, improving wine quality, focusing on a sustainable vitiviniculture.

Read More

Unravelling Saccharomyces cerevisiae biosynthethic pathways of melatonin, serotonin and hydroxytyrosol  by UPLC-HRMS Isotopic labelling analysis

The main objective is to unravel the yeast biosynthetic pathways for MEL, SER and HT by using the respective labelled amino acids precursors: 15N2-L tryptophan and 13C-tyrosine.
The alcoholic fermentation experiments are performed with two different commercial
S cereviseae yeasts using synthetic must with the addition of the labelled compounds and the bioactive compounds were followed during the fermentation process. Six biological replicates of the fermentations were considered. MEL, SER and HT were analysed by UHPLC coupled to High Resolution Mass Spectrometry (HRMS). Accurate mass determination allowed to unequivocally distinguishing labelled and unlabelled compounds.

Read More