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…

Biotype diversity within the autochthonous ‘Bobal’ grapevine variety

Bobal is the second most widely grown Spanish red grape variety (54,165 has), mainly cultivated in the Valencian Community and especially, in Utiel-Requena region (about 67% of 34,000 has). In this study, agronomic and enological parameters were determined in 98 biotypes selected during 2018 and 2019 in more than 50 vineyards over 50 years-old in the Utiel-Requena region. Moreover, a multi-criteria approach considering temperature and rainfall (Fig. 1A), among other parameters, was made to establish three different zones within the region (Fig. 1B), where in the future the selected biotypes will evaluated. In fact, in 2020, 4 replicates and 12 vines per biotype were planted in an experimental vineyard to preserve this important intra-cultivar diversity.

Performance of Selected Uruguayan Native Yeasts for Tannat Wine Production at Pilot Scale

The wine industry is increasing the demand for indigenous yeasts adapted to the terroir to produce unique wines that reflect the distinctive characteristics of each region. In our group, we have identified and characterized 60 native yeast strains isolated from a vineyard in Maldonado-Uruguay, in which three strains stood out: Saccharomyces cerevisiae T193FS, Saturnispora diversa T191FS, and Starmerella bacillaris T193MS. Their oenological potential was evaluated at a semi-pilot scale in Tannat must vinification in the wine cellar to have a more precise and representative evaluation of the final product.

Differences in metabolism among species and hybrids of the genus Saccharomyces during wine fermentation unveiled by multi-omic analysis 

Yeast species S. cerevisiae, S. uvarum, S. kudriavzevii and their hybrids present clear metabolic differences, even when we compared S. cerevisiae wine versus wild strain. These species and hybrids produced significantly higher amounts of glycerol, organic acids, 2,3-butanediol, and 2-phenyl ethanol and a reduction of the ethanol yield, properties very interesting in the sector to deal with climate change effects. To understand the existing differences, we have used several omics techniques to analyze the dynamics of the (intra- and extracellular) metabolomes and/or transcriptomes of representative strains of S. cerevisiae, S. uvarum, S. kudriavzevii, and hybrids.

The combined use of Lachancea thermotolerans and lactic bacteria in wine technology

The production of most red wines that are sold involves an alcoholic fermentation carried out by yeasts of the Saccharomyces genus, and a subsequent fermentation carried out by lactic bacteria of the Oenococus oeni species after the first one is fully completed. However, the traditional process can face complications, which can be more likely in grape juices with high levels of sugar and pH. Because of climate change, these situations are more frequent in the wine industry. The main hazards in those scenarios are halts or delays in the alcoholic fermentation or the growth of unwanted bacteria while the alcoholic fermentation is not done yet and the wine still has residual sugars.

Investigation of cellulose nanofiber-based films used as a protective layer to reduce absorption of smoke phenols into wine grapes

Volatile phenols from wildfire smoke are absorbed by wine grapes, resulting in undesirable smoky and ashy sensory attributes in the affected wine.[1] Unfortunately the severity of wildfires is increasing, particularly when grapes are ripening on the vine. The unwanted flavors of the wine prompted a need for solutions to prevent the uptake of smoke compounds into wine grapes. Films using cellulose nanofibers as the coating forming matrix were developed as an innovative means to prevent smoke phenols from entering Pinot noir grapes. Different film formulations were tested by incorporating low methoxy pectin or chitosan.