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…

Optimization of the ripening time of new varieties descendants of Monastrell

Given the impact of climate change on viticulture in the Region of Murcia, this paper attempts to expose the possibility of using genetic improvement as a dilemma that allows access to new descendant varieties of the autochthonous variety Monastrell crossed with varieties such as Syrah and Cabernet. Sauvignon, thus obtaining hybrids (Gebas and Myrtia). In it, the chromatic parameters and the phenolic profile of the new varieties will be compared with those obtained by the Monastrell variety at two moments during maturation (12 and 14 º Baumé), to check if the results would allow earlier harvests in these new varieties thus avoiding the decoupling between phenolic and technological maturity, while improving the quality of grapes and wines.

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.

Sustainable management of grapevine trunk diseases

Grapevine trunk diseases (GTD) occur wherever grapes are grown and are considered the main biotic factor reducing yields and shortening vineyards’ lifespan. Currently, no product is available to eradicate GTD once grapevines are infected. Therefore, prophylactic strategies based on pruning wound protection and ‘remedial surgery’, the only eradication method based on the elimination of infected wood and renewal of the vine by means of new canes or suckers, are the only effective strategies available. The Canadian grape and wine industry focusses on a sustainable production and thus, looking for alternatives to chemicals for disease management is a top priority.

Time vs drought: leaf age rather than drought drives osmotic adjustment in V. vinifera cv. Pinot Noir

Global warming and increased frequency and/or severity of drought events are among the most threatening consequences of climate change for agricultural crops. In response to drought, grapevine (as many other plants) exhibits osmotic adjustment through active accumulation of osmolytes which in turn shift the leaf turgor loss point (TLP) to more negative values, allowing to maintain stomata opened at lower water potentials1. We investigated the capacity of Pinot noir leaves to modulate their osmotic potential as a function of: (i) time (seasonal osmoregulation), (ii) growing temperatures, and (iii) drought events, to enhance comprehension of the resilience of grapevines in drought conditions. We performed trails under semi-controlled field conditions, and in two different greenhouse chambers (20/15 °C vs 25/20 °C day/night). For two consecutive vegetative seasons, grafted potted grapevines (Pinot noir/SO4) were subjected to two different water regimes for at least 30 days: well-watered (WW) and water deficit (WD).

Application of antagonistic Metschnikowia strains against Botrytis cinerea in vineyards 

Less and less chemical plant protection products are approved by the E U. Plant pathogenic fungi become increasingly resistant to the active ingredients that have been around for a long time. Besides, there is a valid demand for effective products that can be applied in organic cultivation.
We examined Metschnikowia strains under laboratory conditions in order to find effective strains against B. cinerea. The antimicrobial mechanism of these yeasts is based on the competition for the ferric ions from the environment. Metschnikowia cells release the pulcherriminic acid which chelates with Fe3+, forming the pigment pulcherrimin.