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…

Perception, liking and emotional response of tropical fruit aromas in Chardonnay wines

Tropical fruit aromas in wines are thought to be important to wine consumers, although there is little research to confirm this statement. With so many wine styles available, it has become important to understand the qualities that are desirable to consumers and how to achieve those qualities. Thiols and esters are compounds that have been found to cause tropical fruit aromas in chardonnay (ref). Fermentation temperature gradients and skin contact were found to increase these compounds using micro scale fermentations. This work aimed to scale up these fermentations/operations to determine if the desired tropical fruit aromas could still be achieved and if there is a perceivable difference in tropical fruit aromas, liking, and emotional response in the wines at the consumer level.

Wine microbial diversity and cross-over applications: emerging results and future perspectives

AIM: Cross-over applications are an emerging technological approach in food microbiology where a microorganism from one traditional specific fermentation process is used to improve quality and safety in another agri-food production/chain (Dank et al., 2021). A complex microbial diversity is found in association with fermentation in wine, including Saccharomyces, non-Saccharomyces and malolactic bacteria,  all microorganisms versatile in terms of enological utilisation (Tempère et al., 2018). Here, we propose a systematic literature review highlighting the existing trends and possible future applications related to cross-over exploitation of wine-related microbiota. 

Caratterizzazione vitivinicola delle “Terre del Piacenziano” ricomprese nella zona D.O.C. “colli piacentini” attraverso l’analisi sensoriale dei vini prodotti

I territori della Riserva Geologica del Piacenziano sono parte del pedeappennino piacentino e sono noti per essere la culla del Pliocene, quel periodo di storia della Terra compreso tra 5.3 e 1.8 milioni di anni fa. Gli strati argillosi e sabbiosi riccamente fossiliferi qui presenti sono da sempre oggetto di studi geo-paleontologici tant’è che il Pliocene medio (3.6-2.6 milioni di anni fa) è internazionalmente noto come Piacenziano. Le analisi sensoriali strutturate dei vini qui prodotti hanno evidenziato, soprattutto per il vino Monterosso, le positive peculiarità dei loro caratteri sensoriali e descritto gli scostamenti significativi del loro profilo sensoriale rispetto agli altri vini presi a riferimento.

Novel biorefinery step for grape marc valorisation: polysaccharides extraction by subcritical water

The exploitation of food by-products has garnered significant attention over the past few decades, particularly within the framework of the European Green Deal.

Impact of closures on aroma of godello and torrontés white wines post-bottling

Aromatic composition contributes mainly to the quality aroma of white wine. A natural and gradual evolution of the aroma in the bottle occurs over storage with a very low oxygen content.