terclim by ICS banner
IVES 9 IVES Conference Series 9 OENOLOGICAL TANNINS FOR PREVENTING THE LIGHT-STRUCK TASTE IN WHITE AND ROSÉ WINES

OENOLOGICAL TANNINS FOR PREVENTING THE LIGHT-STRUCK TASTE IN WHITE AND ROSÉ WINES

Abstract

The light exposure of wine can be detrimental as a relevant loss of aromas takes place [1] and light-induced reactions can occur. The latter involves riboflavin (RF), a photosensitive compound, that is fully reduced by acquiring two electrons. When the electron-donor is methionine, the light-struck taste (LST) can appear leading to cooked cabbage, onion and garlic odours-like [2]. The use of oenological tannins can limit the appearance of LST in both model wine [3] and white wine [4]. This research aimed to evaluate the impact of certain oenological tannins, selected in a previous study as the most effective against LST [5], in both white and rosé wines.
Six white wines and two rosé wines (5 still and 3 sparkling wines) produced in different vintages, were added with grape seed, tea and tara tannins (40 mg/L) at bottling or disgorgement. The wines were stored in the dark until the light exposure that was carried out under controlled condition [3] at bottling, and after 4 and 9 months of storage. Tannin-free wine samples were considered at each sampling point as control. The total flavonoids (FLVs), the color index (at 420 nm or 520 nm) and the content of RF were determined. The sensory analysis was also performed.
As expected, the addition of oenological tannins led to an increase of FLVs reaching the highest concentrations in the presence of tara tannins followed by tea tannins; a comparable content of FLVs was ob-served in control wines and those added with grape seed tannin. Only slight color index changes were found in the wines added with tannins. The light exposure did not affect neither FLVs nor the color index. In the samples stored in the dark, the content of RF ranged from about 50 μg/L (in 2 white sparkling wine samples) up to 130 μg/L that decreased when the wines were kept under light. The perception of bitterness and astringency was evident in particular with tara and grape seed tannins getting stronger especially in the 2 low-RF wine samples after the light exposure. A decrease of the overall aromatic profile was evidenced after the light exposure and LST was less perceived in the presence of tea tannins that seemed to limit aroma loss.
This study evidenced the impact of the wine on the light-induced fault that can have different wine-dependent facets and it seems of higher intensity in younger wines. Among the oenological tannins tasted, tea tannin was the most effective against LST and, in some cases, also in limiting the aroma decay.

 

1. Carlin S., Mattivi F., Durantini V., Dalledonne S., Arapitsas P. (2022). Flint glass bottles cause white wine aroma identity degradation. PNAS, 119, e2121940119 https://doi.org/10.1073/pnas.2121940119
2. Fracassetti D., Di Canito A., Bodon R., Messina N., Vigentini I., Foschino R., Tirelli A. (2021). Light-struck taste in white wine: Reaction mechanisms, preventive strategies and future perspectives to preserve wine quality. Trends in Food Science & Technology 112, 547-558. https://doi.org/10.1016/j.tifs.2021.04.013
3. Fracassetti D., Limbo S., Pellegrino L., Tirelli A. (2019). Light-induced reactions of methionine and riboflavin in model wine: Effects of hydrolysable tannins and sulfur dioxide. Food Chemistry, 2019, 298, 124952. https://doi.org/10.1016/j.food-chem.2019.124952
4. Fracassetti D., Limbo S., Messina N., Pellegrino L., Tirelli A. (2021). Light-struck taste in white wine: Protective role of glutathione, sulfur dioxide and hydrolysable tannins. Molecules 26, 5297. https://doi.org/10.3390/molecules26175297
5. Fracassetti D., Messina N., Saligari A., Tirelli A. (2023). Evaluation of oenological tannins for preventing the light-struck taste. Food Chemistry 404, 134563. https://doi.org/10.1016/j.foodchem.2022.134563

Acknowledgments The work was supported by European Agricultural Fund for Rural Development [Enofotoshield project; D.d.s. 1 luglio 2019 – n. 9551 , B.U. R.L. Serie Ordinaria n. 27 – 04 luglio 2019].

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Article

Authors

Daniela Fracassetti1,*, Alessio Altomare1, Denis Allieri1, Antonio Tirelli1

1. Department of Food, Environmental and Nutritional Sciences (DeFENS), Universit. degli Studi di Milano, Via G. Celoria 2, 20133 Milan, Italy

Contact the author*

Keywords

Riboflavin, Light exposure, Wine fault, Storage

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

SIP and save the planet: a sensory and consumer exploration of australian wines made from potentially drought-tolerant white wine grapes

In order to attenuate the effects of climate change on the ability to cultivate quality wine grape vines in Australia, it is essential to adapt to the projected less favourable Australian climate scenarios. One response may be to convert a portion of the current grapevine plantings to those varieties that demand less water and can tolerate increased heat. This investigation aimed to (i) generate sensory profiles and (ii) obtain knowledge about Australian wine consumers’ preferences and opinions of Australian wines made from potentially drought tolerant, white wine grape varieties not traditionally cultivated in Australia. A Rate-All-That-Apply (RATA) sensory panel (n = 49) generated sensory profiles of 44 commercial white wines made from 7 different white grape varieties (Arinto, Fiano, Garganega, Greco, Verdejo, Verdelho and Vermentino), plus two benchmark examples each of an Australian Riesling, Pinot Gris and Chardonnay wine.

HYBRID GRAPEVINE CV BACO BLANC, BETWEEN TRADITION AND MODERNISM: FOCUS ON ENDOGENOUS EUGENOL AS RESISTANCE FACTOR TO BOTRYTIS CINEREA

The well-known antifungal and antibiotic molecule, eugenol, is widely spread in various plants including clove, basil and bay. It is also abundant in the hybrid grapevine cultivar (cv) Baco blanc (Vitis vi-nifera x Vitis riparia x Vitis labrusca), created by François Baco (19th century) in the Armagnac region. This study confirmed this cv as highly resistant to Botrytis cinerea by comparing fruit rot incidence and severity with two Vitis vinifera cultivars: Folle Blanche and Ugni Blanc. We have demonstrated the efficiency of eugenol in vitro, by further investigating the effect of small concentrations of eugenol, 3 to 4 ppm (corresponding to IC10), on B. cinerea. By comparing the two major modes of action (direct or volatile antibiosis), the vapour inhibiting effect of eugenol was more powerful. In the skin of Baco blanc berry, the total eugenol concentration reached a maximum at veraison, i.e. 1118 to 1478 μg/kg.

‘TROPICAL’ POLYFUNCTIONAL THIOLS AND THEIR ROLE IN AUSTRALIAN RED WINES

Following anecdotal evidence of unwanted ‘tropical’ character in red wines resulting from vineyard interventions and a subsequent yeast trial observing higher ‘red fruit’ character correlated with higher thiol concentrations, the role of polyfunctional thiols in commercial Australian red wines was investigated.
First, trials into the known tropical thiol modulation technique of foliar applications of sulfur and urea were conducted in parallel on Chardonnay and Shiraz.1 The Chardonnay wines showed expected results with elevated concentrations of 3-sulfanylhexanol (3-SH) and 3-sulfanylhexyl acetate (3-SHA), whereas the Shiraz wines lacked 3-SHA. Furthermore, the Shiraz wines were described as ‘drain’ (known as ‘reductive’ aroma character) during sensory evaluation although they did not contain thiols traditionally associated with ‘reductive’ thiols (H2S, methanethiol etc.).

LARGE SURVEY OF THE CHEMICAL COMPOSITION OF WINES RESULTING OF THE PRESSING OF RED WINE MARC. FIRST RESULTS

In the Bordeaux vineyards, press red wine represents about 15% of the volume of wines. Valuing this large volume of press wine is necessary from an economic point of view, of course, but also because of their organoleptic contribution to the blend. Nevertheless, there is a lack of recent knowledge on the composition of press wines. This work aims to establish an initial assessment of their composition (aromatic and polyphenolic) and to set up hypothesis on to the links with their sensorial identity.

HOW OXYGEN CONSUMPTION INFLUENCES RED WINES VOLTAMMETRIC PROFILE

Phenolic compounds play a central role in sensory characteristics of wine, such as colour, mouthfeel, flavour and determine its shelf life. Furthermore, the major non-enzymatic wine oxidation process is due to the catalytic oxidation of phenols in quinones. Due their importance, during the years have been developed different analytical methods to monitor the concentration of phenols in wine, such as Folin-Ciocalteu method, spectrophotometric techniques and HPLC. These methods can also be used to follow some oxidation-related chemical transformations.