OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 Grape seed powder as an alternative to bentonite for wine fining

Grape seed powder as an alternative to bentonite for wine fining

Abstract

PR proteins can cause haze in wines, and the risk is to keep the wine unsold. Generally, in winemaking bentonite solves this problem by removing proteins, but it is not a renewable resource, has poor settling, which means difficulty in filtering after use and a considerable loss of wine, it is not a specific adsorbent and may reduce aromas and flavor compounds. This work studied the use of grape seeds powder (GSP) to remove haze-forming proteins from wine and grape juice. GSP was tried both roasted 180°C x 10 minutes and unroasted, while contact time was set at one hour and two hours for comparison. GSP was tried first on four different heat-unstable wines in small-scale experiments. The results showed that GSP removed PR proteins and permitted to achieve heat stability (DNTU<2) but with high doses (25-32 g/L) of addition. A similar reduction of PR proteins was obtained in all the wines after 1-h contact time with unroasted GSP as wells as with roasted GSP, which suggests that roasting did not substantially alter the protein-binding capability of GSP. Contact time (1 or 2 hours) did not change the efficacy of protein removal suggesting that the reaction between grape tannins and proteins occurs within one hour. Treated wines showed changes in the matrix composition, with increased phenolic contents (A280) and improved yellow color (CIELAB b* parameter). As for the experiments with grape juice, GSP was added in two juices before fermentation to observe the impact on the composition of the finished wines. Roasted GSP was chosen as the fining agent and the contact time was 1 hour. A lower amount of GSP (5 g/L) was observed to be needed to heat-stabilize (DNTU<2) the juices. The corresponding wines showed minor changes in the matrix composition, perhaps because of phenolic-protein interaction and precipitation during the fermentation or degradation via non-enzymatic processes. These results suggested that GSP may be a viable alternative to bentonite. Furthermore, being a by-product of winemaking, GSP utilization would improve the environmental sustainability of winemaking processes.

DOI:

Publication date: June 10, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Elia Romanini, Jacqui M. McRae, Donato Colangelo, Milena Lambri

The Australian Wine Research Institute, Waite Precinct, Hartley Grove cnr Paratoo Road, Urrbrae (Adelaide), PO Box 197, Glen Osmond, SA 5064, Australia.
UniversitàCattolica del Sacro Cuore – DiSTAS Via Emilia Parmense, 84, 29122 Piacenza, Italy.

Contact the author

Keywords

grape seeds, bentonite, fining, hazing proteins 

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Terroir and Typicity: proposed definitions for two essential concepts in the understanding of Geographical Indications and sustainable development

The content of this communication arises from the deliberations of a working group mandated within the framework of the INRA-INAO 2000-2003 research convention, which brought together INAO representatives and researchers who had worked on AOCs or PGIs, in disciplines from the sphere of the humanities (consumer science, marketing, rural development) and biotechnical sciences (agronomy, animal production science, technology, biochemistry).

Read More

Geological, mineralogical and geochemical influences on the cultivation of vines

Aims: The aims of this study are to determine the influences of the local geology, mineralogy and geochemistry of surroundings, substrate and soil on the cultivation of vines, these as an additional factor of specificity and locality in the production of wine and definition of terroir, as well as for the discrimination of local variance of substrate and soil properties for the strategic management of cultivation plots and/or the evaluation of new cultivation regions, necessary within a scope of global climate change.

Read More

Adsorption of tetraconazole by organic residues and vineyard organically-amended soils 

Spain is the country with the largest wine-producing area in the EU and its productivity is largely controlled applying fungicides. However, residues of these compounds can move and contaminate surface and groundwater. The objective of this work was to evaluate the capacity of bioadsorbents from different origin to adsorb and immobilize tetraconazole by themselves or when applied as organic soil amendment, and to prevent soil and water contamination by this fungicide. The adsorption of tetraconazole by 3 organic residues: spent mushroom substrate (SMS), green compost (GC) and vine pruning sawdust (VP), as well as by vineyard soils unamended and amended individually with these residues at 1.5% (w/w) was evaluated using the batch equilibrium technique.

Read More

Effects of mesoclimate on the yield, quality and phenolic maturity of Grenache

The potential climate change, due to global change, will increase temperature general and could increase at local level. These changes are not going to be the same in different parts of the world, being especially important in the Mediterranean Basin.

Read More

The environmental impact of viticulture: analysis of the influence type of biofertilisers on wine quality and microbiology activity of soil

The trial was conducted in variety/rootstock Riesling/Kober 5 BB in the vineyard district of Vrsac. The vineyard was planted in 1996 on a south-facing slope, with rectangular type pruning of 3×1 m. The training system is of symmetric cordon type and mixed type pruning is practiced.

Read More