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IVES 9 IVES Conference Series 9 EFFECTS OF WINEMAKING FACTORS AND AGEING ON THE POLYPHENOLIC AND COLORIMETRIC PROFILES IN RED WINES PRONE TO COLOUR INSTABILITY

EFFECTS OF WINEMAKING FACTORS AND AGEING ON THE POLYPHENOLIC AND COLORIMETRIC PROFILES IN RED WINES PRONE TO COLOUR INSTABILITY

Abstract

The effects of (A) grape freezing, and (B) malolactic fermentation, have been evaluated on the chemical and colorimetric profiles of red wines from Schiava grossa cv. grapes, thus prone to colour instability. The aim was to observe if specific variables (e.g. grape freezing) could improve the extraction and stability of pigments. The samples were studied from musts up to twelve months in bottle. The study was conducted with independent parallel micro-vinifications (12 = 4 theses x 3 replicates) under strictly-controlled conditions. The measured parameters included: 1) sugars, organic acids and %ABV (measured by specific enzymatic methods or by OIV reference methods), 2) dissolved oxygen (measured according to OIV protocols), 3) semi-quantitative determination of pigments, profile of non-anthocyanidin phenols, and profile of condensed tannins (LC-QqQ/MS [1]), spectrophotometric indexes (Hue and Intensity), colorimetric indexes (CIELab parameters), and the volatile profiles (GCxGC-ToF/MS [2]). A striking relation among the abundances of four anthocyanidin monoglucosides (peonidin-3-glu, malvidin-3-glu, petunidin-3-glu, and cyanidin-3-glu) has been observed in the musts from frozen grapes, but not in wines from frozen or non-frozen grapes. Cyclic procyanidins showed neither significant differences in concentration in must and wine due to any specific applied factor, nor due to specific treatments (such as with bentonites), proving again their applicability as markers for the grape variety in wine [3]. A substantial drop in peonidin-3-glu over the vinification (the main anthocyanin in Schiava cv. grapes) was studied in relation to the applied study factors. Grape freezing increased the extraction of peonidin-3-glu in the must, though the rate of its subsequent loss was faster than in wines from non-frozen grapes. Nonethe-less, peonidin-3-glucoside was still more concentrated in the wines from frozen grapes than in wines from non-frozen grapes up to wine bottling. The wines made from frozen grapes and without malolac-tic fermentation had the highest colorimetric parameters a* (green→red), ΔE* (difference in colour), C* (chromaticity), and ΔH* (difference in tone) colorimetric parameters. b* (blue→yellow) was highest in wines from frozen grapes, but regardless of the application or not of the malolactic fermentation.

 

1. C Dupas de Matos, A., Longo, E., et al. (2020). Foods, vol. 9(4), p. 499
2. Poggesi, S., Dupas de Matos, A., Longo, E., et al. (2021). Molecules, vol. 26(20), p. 6245
3. Longo, E., Rossetti, F., Jouin, A., et al. (2019). Food chemistry, vol. 299, p. 125125

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Edoardo Longo1,2,*,†, Aakriti Darnal1,2, Adriana Teresa Ceci1,2, Simone Poggesi1,2,3, Tanja Mimmo², Emanuele Boselli1,2

1. Oenolab, NOI TechPark Alto Adige/Südtirol, Via A. Volta 13/B, 39100 Bolzano (Italy)
2. Faculty of Agricultural, Environmental and Food Sciences, Free University of Bozen-Bolzano, Piazza Università 5, 39100 Bolzano (Italy)
3. Food experience and sensory testing laboratory (Feast), Massey University, Private Bag 11222, Palmerston North 4410 (New Zealand)

Contact the author*

Keywords

Colour instability, Grape freezing, Chemical profile, Colorimetry

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

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