 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

Replay of the Wine Vision 2040 event

A webinar organised by the UBC Wine Research Centre, on June 25th 2020. About Wine Vision 2040 Wine Vision 2040 is delivered by wine-passionate, high-profile individuals keen to share ideas and views that will spark conversations within wine communities. No...

Cytochrome P450 CYP71BE5 from grapevine (Vitis vinifera) catalyzes the formation of the spicy aroma compound, (-)-rotundone

(-)-Rotundone, an oxygenated sesquiterpene, is a potent odorant molecule with a characteristic spicy aroma existing in various plants including grapes1. It is considered as a significant compound notably in wines and grapes because of its low sensory threshold (16 ng L-1 in red wine, 8 ng L-1 in water) and aroma properties. (-)-Rotundone was first identified in red wine made from the grape cultivar Syrah (regionally called Shiraz) in Australia1, and then it was found in several grape varieties such as Duras, Grüner Veltliner, Schioppettino and Vespolina from Europe2, 3. Several environmental factors affecting the accumulation of (-)-Rotundone during the grape maturation, were reported such as ambient temperature4, soil properties and topography5, soil moisture from irrigation and light exposure in the bunch zone by leaf removal2.

Rootstock impact on foliar symptom expression of esca on Vitis vinifera cv. Cabernet-Sauvignon

Trunk diseases and esca in particular, represent a major threat to the sustainability of the vineyards. The percentages of unproductive vines in a plot could vary from 4% to over 20 % depending on local conditions and vintages.

Viticultural heritage in mountain territories of Catalonia: prospecting in the region of Osona, northern Spain

The recovery of ancestral or minority vine varieties has been gaining great interest in recent years, among other reasons because it is likely that some of these varieties, due to the fact that they are found in relict areas, have a greater potential for adaptation to external factors (biotic or abiotic) and can minimize the effects that climate change is causing in viticulture. Varieties that can be grown at altitude are currently being sought to combat rising temperatures and prolonged extreme drought conditions. In Catalonia, the Pyrenean expansion of vineyard cultivation is documented from the 10th century and has been related to the “small climatic optimum” (9th-12th centuries) and also to seigniorial power.[1] But different adverse climatic periods and the arrival of Phylloxera by the late 19th century made many of these crops disappear.[2]

The drought, the temperature, and the time: drivers of osmotic adjustment?

Context and purpose of the study. Leaf osmotic adjustment (i.e., active accumulation of osmolytes in the cells) has been reported in grapevines in response to drought and as a natural process throughout the growing season (seasonal osmotic adjustment).