terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Optimization of the acquisition of NIR spectrum in grape must and wine 

Optimization of the acquisition of NIR spectrum in grape must and wine 

Abstract

The characterization of chemical compounds related with quality of grape must and wine is relevant for the viticulture and enology fields. Analytical methods used for these analyses require expensive instrumentation as well as a long sample preparation processes and the use of chemical solvents. On the other hand, near-infrared (NIR) spectroscopy technique is a simple, fast and non-destructive method for the detection of chemical composition showing a fingerprint of the sample. It has been reported the potential of NIR spectroscopy to measure some enological parameters such as alcohol content, pH, organic acids, glycerol, reducing sugars and phenolic compounds.

This work focuses on the evaluation of the optimal parameters and pathlengths for fast measurement of the UV/VIS/NIR/MIR spectra in grape must and wine. The study was carried out with three different type of samples: (i) red wine cv Mencía, (ii) white wine cv Albariño, and (iii) grape must cv Albariño. Absorbance spectra were collected in rectangular quartz cuvettes of different optical pathlengths (1, 2, 5, and 10 mm) where different bandwidth parameters were tested.

The results indicated that increasing the optical pathlengths of the cuvettes increases the absorption intensity up to a saturation level (absorbance >2.5 units) at long wavelengths using long pathlengths (5 and 10 mm). The interpretation of the spectra also improves with 1 and 2 mm pathlengths. The bandwidth parameters evaluated indicated that using higher values, the spectrum appeared more defined, and the range of analysis was increased, reaching the MIR part of the spectrum.  In conclusion, the best combination of pathlength and bandwidth for the measurement of grape must and wine in the UV/VIS/NIR/MIR range is 1 mm of pathlength cuvette with the bandwidth set at 40 nm.

DOI:

Publication date: October 13, 2023

Issue: ICGWS 2023

Type: Poster

Authors

Manzano JI.1, Cozzolino D.2, Vilanova M.1

1 Instituto de Ciencias de la Vid y el Vino-ICVV (CSIC, UR, GR) 26007 Logroño (España)
2 Centre for Nutrition and Food Sciences (CNAFS), Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, Brisbane, QLD 4072, (Australia)

Contact the author*

Keywords

NIR, wine, must, cuvette, bandwidth

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

Options to replace or reduce the sulphite content in Tannat red wines produced with minimal intervention

Several Uruguayan wineries have begun to produce wines with minimal intervention, to increase the sustainability of their vineyards and wines. These wines are characterized by the minimum intervention in the management of the vineyard, its harvest, vinification, conservation and aging1,2. Sulfur dioxide (SO2) is not used or is used in reduced doses, although chitosan can be substituted or supplemented1. The objective of this research is to evaluate SO2 reduction or replacement options adapted to the production of Tannat red wines with minimal intervention. Vinification of the Tannat grapes with autochthonous yeasts (LN) was carried out during the 2023 vintage.

White grape must processed by UHPH as an alternative to SO2 addition: Effect on the phenolic composition in three varieties

The quantity and distribution of polyphenols in musts play a fundamental role in the white winemaking. This is because these substances are exposed to oxidation reactions, which are catalysed by the polyphenol oxidase (PPO), leading to a decrease in the quality of the wines produced. PPO is inactivated by SO2, but currently, due to the restrictions of the legislation, other methodologies are being investigated. Ultra-High Pressure Homogenization (UHPH) is a non-thermal physic technology that exerts an ultrahigh pressure pumping (>200 MPa) of a fluid through a valve in a continuous system.

Wine without added SO2: Oxygen impact and color evolution during red wine aging

SO2 play a major role in wine stability and evolution during its aging and storage. Winemaking without SO2 is a big challenge for the winemakers since the lack of SO2 affects directly the wine chemical evolution such as the aromas compounds as well as the phenolic compounds. During the red wine aging, phenolic compounds such as anthocyanin, responsible of the red wine colour, and tannins, responsible of the mouthfeel organoleptic properties of wine, evolved quickly from the winemaking process to aging [1]. A lot of new interaction and molecules occurred lead by oxygen[2] thus the lack of SO2 will induce wine properties changes. Nowadays, the phenolic composition of the wine without added SO2 have not been clearly reported.

Typicality of Rioja wines: identification of sensory profiles for the three subregions of DOCa Rioja

Within the DOCa Rioja three main production areas are differentiated: Rioja Alta (RA), Rioja Alavesa (RAv) and Rioja Oriental (RO). They are three diverse territories with particular characteristics that are claimed to give rise to differentiated profiles. The present work aims at evaluating the sensory diversity of young commercial red wines in these three subregions. Therefore 30 young red wines (mainly Tempranillo and vintage 2021), ten from each subregion, were sensory described following a non-verbal free sorting task and a verbal free comment task by 32 well-established Rioja winemakers.

Reconstructing ancient microbial fermentation genomes from the wine residues of Herod, Roman king of Judea

The fortress of the Herodium, built towards the end of the first century BCE/ante Cristo, on the orders of Herod the Great, Roman client king of Judea, attests the expansion of Roman influence in the eastern Mediterranean. During archaeological excavations of the Herodium in 2017[1], a winery was discovered on the ground floor of the palace, with an assortment of clay vessels in situ, including large dolia – clay fermentation vessels each capable of fermenting up to 300-400 L of wine. Thanks to the recent progresses in the field of paleogenomics[2], we could analyse the organic material consistent with grape pomace at the bottom of these vessels, by extracting and sequencing the DNA using shotgun metagenomics and targeted capture, aiming for enrichment of DNA from fermentation associated microbes.