Terroir 2004 banner
IVES 9 IVES Conference Series 9 Screening of different commercial wine yeast strains: the effect of sugar and copper additions on fermentation and volatile acidity production

Screening of different commercial wine yeast strains: the effect of sugar and copper additions on fermentation and volatile acidity production

Abstract

The aims of this study were to examine the effect of high sugar concentrations of must and copper residues on different commercial wine yeasts. Copper originating from pesticides has been known to inhibit yeast, but it’s effect on fermentation performance and VA production of different yeast strains had not been investigated in detail. Fermentation performance was monitored through mass loss and growth as measured at OD600. VA, glucose and fructose concentrations were monitored after 21 days of fermentation with the FOSS 2000 Grape Scan. Certain strains were initially less affected by high sugar concentrations than others, but only musts fermented with strains VIN13, WE372, N96 and L2056 contained less than 11 g/L fructose after 21 days. VIN13 and RJ11 produced the lowest VA in the 21°B, 25°B and 28°B musts. Higher VA concentrations were also produced in higher sugar containing musts. It must, however, be kept in mind that the nutrient requirements of yeast stains differ which can affect this, although these must all received sufficient DAP. The fermentation ability of six trains was also monitored in must containing Cu concentrations close to the legal limit in SA. Strains NT50, Collection Cépage Cabernet (CC) and D80 were not significantly affected, whereas musts fermented with strains VIN13, NT112 and RJ11 contained significantly more glucose and fructose after fermentation. The utilization of fructose was also more affected by the copper than that of glucose, which might further had contributed to a sluggish fermentation. This inhibition was also reflected in the growth of the different yeast strains. Copper also increased the VA production by yeast strains with certain strains being affected more than others.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

W.J. Du Toit (1), J. Ferreira (1), and M. Du Toit (1,2)

(1) Department of Viticulture and Oenology
(2) Institute for Wine Biotechnology, Stellenbosch University, Z.A-7600, Stellenbosch, South Africa

Contact the author

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

Flavanol glycosides in grapes and wines : the key missing molecular intermediates in condensed tannin biosynthesis ?

Polyphenols are present in a wide variety of plants and foods such as tea, cacao and grape1. An important sub-class of these compounds is the flavanols present in grapes and wines as monomers (e.g (+)-catechin or (-)-epicatechin), or polymers also called condensed tannins or proanthocyanidins. They have important antioxidant properties2 but their biosynthesis remains partly unknown. Some recent studies have focused on the role of glycosylated intermediates that are involved in the transport of the monomers and may serve as precursors in the polymerization mechanism3, 4. The global objective of this work is to identify flavanol glycosides in grapes or wines, describe their structure and determine their abundance during grape development and in wine.

Regenerative agricultural approaches to improve ecosystem services in Mediterranean vineyards

REVINE is a 3 year European projected funded by PRIMA programme which proposes the adoption of regenerative agriculture practices with an innovative and original perspective, in order to improve the resilience of vineyards to climate change in the Mediterranean area. The potential for innovation lies in developing and combining new approaches that make agriculture more environmentally sustainable and enable a circular economy capable of improving farmers’ incomes. Primarily REVINE aims to improve soil health and biodiversity by promoting the multiplication of soil saprophytic microorganisms and the presence of useful microorganisms linked to the life cycle of the plant, such as rhizobacteria (PGPR) and fungi (PGPF) that promote plant growth which, in addition to increasing plant performance, increase tolerance to biotic and abiotic stresses.

qNMR metabolomics a tool for wine authenticity and winemaking processes discrimination

qNMR Metabolomic applied to wine offers many possibilities. The first application that is increasingly being studied is the authentication of wines through environmental factors such as geographical origin, grape variety or vintage (Gougeon et al., 2019).

Wine by-products valorisation by green chemistry methods: Impact of the extraction process on the structure, functionalities and activity of the extracted molecules

Wine by-products valorisation by green chemistry methods: Impact of the extraction process on the structure, functionalities and activity of the extracted molecules

Water and nutritional savings shape non-structural carbohydrates in grapevine (Vitis vinifera L.) cuttings

Global changes and sustainability challenge researchers in saving water and nutrients. The response of woody crops, which can be forced at facing more drought events during their life, is particularly important. Vitis vinifera can be an important model for its relevance in countries subjected to climate changes and its breeding, requiring cuttings plantation and strong pruning.