Macrowine 2021
IVES 9 IVES Conference Series 9 New plant protein extracts as fining agents for red wines

New plant protein extracts as fining agents for red wines

Abstract

AIM: Quinoa (Chenopodium quinoa) is a non-allergenic pseudocereal with a high protein content. The aim of this work was to determine the phenolic fining ability of quinoa protein extracts (QP), and to compare them against commercial proteinaceous fining agents.

METHODS: Quinoa seeds of the variety Regalona-Baer, cultivated in Santa Rosa Experimental Center (Chillán, Chile) and red wine samples (Petit Verdot and Malbec) from the Maule Region of Chile were used for this study. QP were obtained by alkaline extraction and isoelectric precipitation. The protein content of quinoa samples and QP was determined by the Dumas method with a nitrogen to protein conversion factor of 5.85. SDS-PAGE profile of QP was analysed by electrophoresis, according to the Laemmli method (1). The fining efficacy of QP was evaluated at 20°C at different doses and contact times (48 and 96 h) and compared against three commercial fining agents of animal and vegetal origin (Vegefine, Vegecoll and Gelatin). The total tannin content in wines were measured spectrophotometrically by the methyl cellulose precipitable (MCP) tannin assay (2) and the Harbertson-Adams tannin assay (3). The total phenolics were quantified by the Folin-Ciocalteu assay (4). The anthocyanin content was determined according to the HPLC-DAD method OIV-MA-AS315-11 for the analysis of major anthocyanins in red and rosé wines.

RESULTS: QP showed a content of 60% protein with molecular weight distribution of ̴ 35 kDa, ̴ 22 kDa and ̴ 10 kDa. QP treatments significantly reduced turbidity, total tannin and total phenolics in Petit Verdot wine at the two doses tested (30 and 50 g/hL) and in a similar proportion than the commercial fining agents. For all fining agents it was observed that tannin content decreased more after 96 hours of contact time (11-16%) than after 48 hours (5-11%) of treatment. Like so, QP fining resulted in a significant reduction of the tannin content in Malbec fined wine (20-25%), more so than when using the commercial fining agents (3-10%). For both wines, the color of the fined samples (measured as malvidin-3-glucoside equivalent at 520 nm) was not significantly affected by the treatments with QPs.

CONCLUSIONS:

 The results obtained suggest that QP could be an interesting alternative for wine fining with plant derived proteins; therefore, more studies on this subject are being performed.

DOI:

Publication date: September 10, 2021

Issue: Macrowine 2021

Type: Article

Authors

Liudis L. Pino

University of Talca,V. Felipe LAURIE, University of Talca

Contact the author

Keywords

 wine, fining, plan ptoteins, quinoa, phenolics, tannin

Citation

Related articles…

Energy optimization of the Charmat-Martinotti refermentation process

The european union has estimated that energy consumption for wine production is about 1,750 million kwh per year, of which 500 million kwh is attributable to italy. In recent years, Italy has emerged as the world’s leading wine producer with about 50 million hectoliters per year. About 20 percent (9.8 million hectoliters) of Italian wine is marketed after refermentation according to the Charmat-Martinotti method.

DETERMINATION OF FREE AMINO ACIDS, AMINO ACID POTENTIAL AND PROTEASE ACTIVITY IN THE LEES AND STILL WINES OF CHAMPAGNE

Prior to winemaking, organic or mineral nitrogen compound concentrations are usually measured in the vineyard and in grape musts. These indicators facilitate vine cultivation decisions, usually through yield or vigor. During vinification, yeast and bacteria metabolize nitrogen compounds in the musts in order to generate biomass. After fermentation, the microorganisms rerelease a part of this nitrogen as soluble compounds into the wines. Another part remains bound in the lees and can be lost during racking. The must’s natural nitrogen quantities, additional supplements during fermentation, and lees contact management enhance the release of nitrogen compounds to the wines. During ageing these nitrogen compounds – primarily the amino acids – are implicated in the generation of odorous compounds such as heterocycles(1).

Effect of rootstock and preplant fumigation on plant parasitic nematode development in Washington wine grapes

In Washington State, the majority of winegrape (Vitis vinifera) vineyards are planted to their own roots. This practice is possible due to the lack of established phylloxera populations, and is preferred due to the ease of retraining after damaging winter cold events. However, own-rooted V. vinifera is generally susceptible to most plant parasitic nematodes that attack grape. In Washington State, management of nematodes is dominated by preplant soil fumigation. One practice that may mitigate economic loss due to nematodes is the adoption of nematode-“resistant” rootstocks.

Development of a LC-FTMS method to quantify natural sweeteners in red wines

The quality of a wine is largely related to the balance between its sourness, bitterness and sweetness. Recently, molecules coming from grapes have been showed to notably contribute to sweet taste of dry wines. To study the viticultural and oenological parameters likely to affect their concentration, their quantification appears of high interest and subsequently requires powerful analytical techniques. Therefore, a new method using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) was developed and validated to quantify epi-DPA-3′-O-β-glucopyranoside acid (epi-DPA-G) and astilbin, sweet molecules identified in wine. Three gradients were tested on five different C18 columns (Hypersil Gold, HSS T3, BEH, Syncronis and Kinetex).

To a better understanding of the impact of vine nitrogen status on volatile thiols from plot to transcriptome level

Volatile thiols contribute largely to the organoleptic characteristics and typicity of Sauvignon blanc wines. Among this family of odorous compounds, 3-sulfanylhexan-1-ol (3SH) and 4-methyl-4-sulfanylpentan-2-one (4MSP) have a major impact on wine flavor. These thiols are formed during alcoholic fermentation by the yeast from odorless and non-volatile precursors found in the berry and the must. The effect of vine nitrogen status on 3SH and 4MSP in Sauvignon blanc wine and on the glutathionylated and cysteinylated precursors of 3SH (Glut-3SH and Cys-3SH) was investigated in this study.