terclim by ICS banner
IVES 9 IVES Conference Series 9 EFFECT OF OXIDATION ON LOW MOLECULAR WEIGHT PHENOLIC FRACTION, SALIVARY PROTEINS PRECIPITATION AND ASTRINGENCY SUBQUALITIES OF RED WINES

EFFECT OF OXIDATION ON LOW MOLECULAR WEIGHT PHENOLIC FRACTION, SALIVARY PROTEINS PRECIPITATION AND ASTRINGENCY SUBQUALITIES OF RED WINES

Abstract

Changes in the low molecular weight phenolic fraction, obtained by liquid-liquid microextraction technique, were studied after controlled oxidation of two typologies of Sangiovese wines (Brunello di Montalcino and Chianti Classico) belonging to two vintages (2017 and 2018). The fractions were characterized by LC-MS and quantified by HPLC. The most abundant extracted compounds were the phenolic acids. The effect of oxidation, vintage, and wine typology was stated by a three-ways ANOVA. Gallic and syringic acids significantly increased after oxidation while (–)-epicatechin decreased the most. The interaction and precipitation with salivary proteins, mechanism at the basis of astringency, was carried out at three phenolic concentrations (3.0–5.0–7.5 g/L). The amount of salivary proteins and phenolic compounds were in turn analysed by HPLC. Only the caftaric, cis- and trans-coutaric acids, and procyanidin dimer B7 showed a significant precipitation with salivary proteins. The oxidated wine fractions showed a high interaction and more precipitation with salivary proteins than the not oxidated ones. However, the high precipitation of the low molecular weight phenolics was not correlated with the sensory astringency of wines. Control wines were characterized by unripe astringency felt with acidity, described as greenness subquality, due to the high content of (+)-catechin, (–)-epicatechin, caftaric acid and myricetin-3-O-glucoronide in the fractions. The decrease of such phenolic compounds by oxidation was correlated with the corresponding increase of silkiness and velvety sensation in the oxidated wines.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Alessandra Rinaldi¹, Elsa Brandão², Monica Jesus², Angelita Gambuti¹, Victor De Freitas², Susana Soares²

1. Dipartimento di Agraria, Sezione di Scienze della Vigna e del Vino, Università degli Studi di Napoli Federico II, Viale Italia, 83100 Avellino, Italy
2. REQUIMTE/LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 689, Porto, Portugal

Contact the author*

Keywords

oxidation, astringency, subquality, greenness

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

WHITE WINES OXIDATIVE STABILITY: A 2-VINTAGE STUDY OF CHARDONNAY CHAMPAGNE BASE WINES AGED ON LEES IN BARRELS

Ultra-premium champagne wines are characterized by a long stay on laths. The goal of the winemaker is to use all possible oenological techniques to keep the aromatic freshness of the future products. To that purpose, some champagne base wines can be aged on lees in oak barrels. However, if it is now acknowledged that such ageing practices contribute to the oxidative stability of dry white wines, no study has been done on Chardonnay champagne base wines designed for a long ageing on laths [1].

CONSENSUS AND SENSORY DOMINANCE ARE DEPENDENT ON QUALITY CONCEPT DEFINITIONS

The definition of the term “quality” in sensory evaluation of food products does not seem to be consensual. Descriptive or liking methods are generally used to differentiate between wines (Lawless et al., 1997). Nevertheless, quality evaluation of a product such as wine can also relate to emotional aspects. As exposed by Costell (2002), product quality is defined as an integrated impression, like acceptability, pleasure, or emotional experiences during tasting. According to the ‘modality appropriateness’ hypothesis which predicts that wine tasters weigh the most suitable sensory inputs for a specific assess- ment (Freides, 1974; Welch & Warren, 1980), the nature of the quality definitions may modulate sensory influences.

FOURIER TRANSFORM INFRARED SPECTROSCOPY IN MONITORING THE WINE PRODUCTION

The complexity of the wine matrix makes the monitoring of the winemaking process crucial. Fourier Transform Infrared Spectroscopy (FTIR) along with chemometrics is considered an effective analytical tool combining good accuracy, robustness, high sample throughput, and “green character”. Portable and non-portable FTIR devices are already used by the wine industry for routine analysis. However, the analytical calibrations need to be enriched, and some others are still waiting to be thoroughly developed.

SENSORY PROPERTIES IMPORTANT TO AUSTRALIAN FINE WINE CONSUMER SEGMENT PERCEPTION OF CHARDONNAY WINE COMPLEXITY AND PREFERENCE

Wine complexity is considered a multidimensional yet equivocal sensory percept. This project uncovered sensory attributes Australian Chardonnay wine consumers associate with Chardonnay wine complexity
and correlations between expert and consumer perceived wine complexity and preference. A
wine consumer test examined 6 Australian Chardonnay wines of three complexity levels designated low (LC1&2), medium (MC1&2), and high (HC1&2) by an expert panel (n = 8) using a benchtop sensory task. Consumers (n = 81) rated their perceived liking using a 9-point hedonic scale; wine complexity with a 5-point scale anchored “low”, “low-medium”, “medium”, “medium-high”, and “high” and lastly, profiled the wines using Rate-All-That-Apply (RATA). Psychographic segmentation with the Fine Wine Instrument
(FWI) generated three segments; Wine Enthusiasts (WE n=29), Aspirants (ASP n=40) and No- Frills (NF n=12).

IMPACT OF GRAPE-ASSOCIATED MOLDS IN FRESH MUSHROOM AROMA PRODUCTION

Mycobiota encountered from vine to wine is a complex and diversified ecosystem that may impact grape quality at harvest and the sensorial properties of wines, thus leading to off-flavors [1-3]. Among known off-flavors in wine, fresh mushroom aroma (FMA) has been linked to some mold species, naturally pre-sent on grapes, producing specific volatile organic compounds (VOC) [4-5]. The most well-known are 1-octen-3-ol and 1-octen-3-one, although many other VOC are likely involved. To better understand the FMA defect, biotic and abiotic factors impacting growth kinetics and VOC production of selected fungal species in must media and on grapes were studied.