terclim by ICS banner
IVES 9 IVES Conference Series 9 EFFECT OF MANNOPROTEIN-RICH EXTRACTS FROM WINE LEES ON PHENOLICCOMPOSITION AND COLOUR OF RED WINE

EFFECT OF MANNOPROTEIN-RICH EXTRACTS FROM WINE LEES ON PHENOLICCOMPOSITION AND COLOUR OF RED WINE

Abstract

In 2022, wine production was estimated at around 260 million hl. This high production rate implies to generate a large amount of by-products, which include grape pomace, grape stalks and wine lees. It is estimated that processing 100 tons of grapes leads to ~ 22 tons of by-products from which ~ 6 tons are lees [1]. Wine lees are a sludge-looking material mostly made of dead and living yeast cells, yeast debris and other particles that precipitate at the bottom of wine tanks after alcoholic fermentation. Unlike grape pomace or grape stalks, few strategies have been proposed for the recovery and valorisation of wine less [2]. Nevertheless, this by-product could become a source of interesting compounds, such as mannoprotein rich extracts (MRE). Therefore, the aim of this work was to obtain MRE from different lees, to characterize them, and to evaluate their effect on wine colour and on the phenolic composition of red wines.

Red, rosé and white wines were used as sources of lees, which were collected after the alcoholic fermentation with different Saccharomyces cerevisiae commercial varieties. The extraction of MRE was performed by physical extraction (autoclave) followed by a purification with ethanol. The protein and polysaccharidic moieties of the purified extracts were characterized by SDS-PAGE, Lowry method, HR-SEC-RID and HPLC-DAD-MS. The obtained MRE were added to a red wine (Vitis vinifera L. cv Tempranillo) and the changes in the phenolic composition and colour were analysed by HPLC-DAD-MS and triestimulus colorimetry, respectively, before and after the stabilization of the wine (involving cold treatment). Results obtained showed that the extraction yield of MRE was efficient (~ 40 mg/g wet lees) for all types of lees assayed, which supports the valorisation of wine lees as a sustainable source of MRE. Interestingly, MRE presented important structural and compositional differences, both in the protein content and in the polysaccharidic profile, although the source of lees, namely red, white and rosé wines, was not the main factor determining these differences, but the winemaking techniques or the S. cerevisiae strain employed. Furthermore, the addition of the MRE to red wine had an effect on the stabilization of wine colour and its phenolic content that rely mainly on the saccharidic characteristics of each MRE. These results pointed out that MRE from wine less could be a potential tool to improve the colloidal stability of wine phenolic compounds.

 

1. Oliveira & Duarte, 2016. Front. Environ. Sci. Eng., 10(1): 168–176.
2. De Iseppi et al., 2020. Food Res. Int., 137, 109352. 

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Marcos, Martín-Andrés¹; Ignacio, García-Estévez¹; M. Teresa, Escribano-Bailón¹; Elvira Manjón¹

1. Department of Analytical Chemistry, Nutrition and Food Science, Universidad de Salamanca, Salamanca, E37007, Spain

Contact the author*

Keywords

lees, mannoprotein, colour wine, phenolic compounds

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

FLAVONOID POTENTIAL OF MINORITY RED GRAPE VARIETIES

The alteration in the rainfall pattern and the increase in the temperatures associated to global climate change are already affecting wine production in many viticultural regions all around the world (1). In fact, grapes are nowadays ripening earlier from a technological point of view than in the past, but they are not necessarily mature from a phenolic point of view. Consequently, the wines made from these grapes can be unbalanced or show high alcohol content. Dramatic shifts in viticultural areas are currently being projected for the future (2).

HAZE RISK ASSESSMENT OF MUSCAT MUSTS AND WINES : WHICH LABORATORY TEST ALLOWS A RELIABLE ESTIMATION OF THE HEATWAVE REALITY?

Wines made from Muscat d’Alexandria grapes exhibit a high haze risk. For this reason, they are systematically treated with bentonite, on the must and sometimes also on wine. In most oenological labora-tories and in companies (trade, cooperatives, independent winegrowers), the test that is by far the most widely used, on a worldwide scale, remains the heat test at 80°C for 30 minutes to 2 hours (and some-times up to 6 hours). The tannin test (sometimes coupled with a heat treatment) and the Bentotest are still used. In this study, we show that all these tests give much higher estimates of the haze risk than the risk assessed by a 24-48h treatment at 42°C, which represents a heat wave.

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

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.

HOW DO ROOTSTOCKS AFFECT CABERNET SAUVIGNON AROMATIC EXPRESSION?

Grape quality potential for wine production is strongly influenced by environmental parameters such as climate and agronomic factors such as rootstock. Several studies underline the effect of rootstock on vegetative growth of the scions [1] and on berry composition [2, 3] with an impact on wine quality. Rootstocks are promising agronomic tools for climate change adaptation and in most grape-growing regions the potential diversity of rootstocks is not fully used and only a few genotypes are planted. Little is known about the effect of rootstock genetic variability on the aromatic composition in wines; thus further investigations are needed.

Metabolomics for grape and wine research: exploring the contributions of amino acids to wine flavour

A critical aspect of wine quality is the overall expression of wine flavour, which is formed by the interplay of volatile aroma compounds, their precursors, and taste and matrix components.
Grapes directly contribute to wine only a small number of potent aroma compounds, and the unique
sensory attributes and perceived quality of a wine result from combining 100s of metabolites of grapes, yeast and bacteria, and oak wood.