IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Determination of Aroma Compounds in Grape Mash under Conditions of Tasting by On-line Near-Infrared Spectroscopy

Determination of Aroma Compounds in Grape Mash under Conditions of Tasting by On-line Near-Infrared Spectroscopy

Abstract

The production of high-quality wines requires the use of high-quality grapes. Some compounds originating from grapes may negatively influence the odour and flavour of the resulting wine in their original form or as precursors for off-odours and –flavours. Therefore, a rapid evaluation of the grapes directly upon receival at the winery is advantageous. Up to now, grape aroma is mainly evaluated by tasting, however, this leads to subjective results. The use of near-infrared (NIR) spectroscopy allows a rapid, objective and destruction-free analysis without previous sample preparation. Moreover, the measurement can be integrated into an existing process without additional sampling.

The aroma compounds in grape mash samples were analysed by gas chromatography-mass spectrometry (GC-MS) under highly comparable conditions to those in the mouth (temperature, pH value, enzymes etc.). This way, only compounds were detected, which are released during tasting. Furthermore, the destruction of compounds and possible artefact formation should be avoided. The determined concentrations of the detected aroma compounds were related to the corresponding NIR spectra of the samples and calibration models were developed for determination by NIR spectroscopy.

Regarding the presence and the concentrations of the detected aroma compounds, differences occurred between samples with varying phytosanitary status of the grapes and for several grape varieties. The addition of artificial saliva solution before measurement did not significantly influence the concentrations of the aroma compounds. Global calibration models for the single aroma compounds showed varying results (0,365 ≤ R2 ≤ 0,976). Separate calibration models for cultivation region and/or grape colour improved the prediction accuracy.

For the majority of the detected aroma compounds at least a semi-quantitative determination by NIR spectroscopy is possible to evaluate the aroma quality of grapes. However, more samples need to be analysed to extend the models and to assure sufficient prediction accuracy.

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

Gehlken Jana1, Pour Nikfardjam Martin2 and Zörb Christian1

1University of Hohenheim, Institute of Crop Science, Dept. Quality of Plant Products and Viticulture (340e)
2State Research Institute for Viticulture and Pomiculture, Traubenplatz 5, 74189 Weinsberg/Germany

Contact the author

Keywords

Near-infrared spectroscopy, grape tasting, grape mash, aroma compounds, calibration

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

The vineyard landscape of the oasis norte of Mendoza Argentina. Economic assessment of the recreational use through contingent valuation method

Oasis Norte’s vineyards of Mendoza Argentina have shaped along their existence, a characteristic landscape; this area is close to Mendoza City

Relationship between chemical parameters of tannins and in-mouth attributes of grape phenolic fractions

Establish relationships between taste and mouthfeel properties of grapes and tannin-related chemical parameters. Tempranillo Tinto and Garnacha Tinta grapes were harvested from distinct blocks in different dates; each sample collection date was separated by one week. Grapes were destemmed and macerated in 15% of ethanol for one week. The polyphenolic fraction (PF) of samples was submitted to solid phase extraction on C18 cartridges and recovered with ethanol. PFs were reconstituted in wine model and their taste and mouthfeel properties were characterised by rate-K-attributes methodology. In parallel, concentration (TC) and activity (TAc) of tannins as well as the concentration of tannins linked to anthocyanins (T-A) were determined using HPLC-UV–VIS.

EVALUATION OF A SEAWEED EXTRACT OF RUGULOPTERYX OKAMURAE AGAINST ERYSIPHE NECATOR IN GRAPEVINE

Powdery mildew, caused by Erysiphe necator, is a widespread disease that causes high economical losses in viticulture. The main strategy to control the disease is the recurrent application of sulphur based phytochemical compounds. However, in order to reduce their accumulation in the environment and promote the sustainability of the sector, the European Commission has applied restrictions to the number of pesticide treatments and the maximum quantity of fungicides to be applied in viticulture. Seaweeds, in particular macroalgae, are marine resources rich in sulphated polysaccharides with bio-protective potential for the plant, representing an environmentally-friendly alternative approach for sustainable wine production.

The Cognac industry: history, successes and challenges

With alcohol consumption steadily declining, the growing popularity of dry january, a fiercely competitive environment, high dry matter inflation, economic upheavals, commercial uncertainties… The wine industry must adapt and offer products that meet consumer expectations, without denying their historical singularities.

Effect of “Terroir” on quanti-qualitative paramethers of “vino nobile di Montepulciano”

In this last ten years period, there has been many integrated and interdisciplinary studies to determine the aptitude of different zones to viticulture (Lulli et al., 1989 ; Costantini, 1992 ; Fregoni et al., 1992). The researches needed some différent knowledges about environment characteristics (soil, climate), ecology, vineyard management, vine genetic, winemaking and sensory analysis. The interaction of all these knowledge produced the assessment about the environmental vocation (Scienza et al., 1992). By means of this metodology, the “viticultural vocation” joined the word “zoning”, that is the territory parting for its ecopedological and geographical characteristics in relation to adaptative answer of winegrape (Morlat, 1989).