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…

Unraveling the complexity of high-temperature tolerance by characterizing key players of heat stress response in grapevine

Grapevine (Vitis spp.) is greatly influenced by climatic conditions and its economic value is therefore directly linked to environmental factors. Among these factors, temperature plays a critical role in vine phenology and fruit composition. In such conditions, elucidating the mechanisms employed by the vine to cope with heat waves becomes urgent. For the past few years, our research team has been producing molecular and metabolic data to highlight the molecular players involved in the response of the vine and the fruit to high temperatures [1]. Some of these temperature-sensitive genes are currently undergoing characterization using transgenesis approaches coupled or not with genome editing, taking advantage of the Microvine genotype [2].

NIR based sensometric approach for consumer preference evaluation

Climate change has had a global impact on grape production, and as a result, developing table grape varieties that can withstand climate-related threats has become a significant goal. However, it is equally important to ensure that these new grape varieties meet the preferences of consumers. To achieve this goal, a procedure has been developed that combines sensory analysis with spectroscopic data collected in the NIR region. Each sample was analyzed using both traditional analytical techniques and non-destructive NIR spectroscopy.

Studio preliminare sulla microzonazione Bioclimatica condotto in un’area viticola collinare

La caratterizzazione bioclimatica del territorio rappresenta un elemento sempre più impor­tante per il miglioramento dell’ attività agricola. La conoscenza degli andamenti assunti dai parametri meteorologici puà consentire di individuare le peculiarità dei singoli appezzamenti aziendali, ottimizzando le scelte sia in termini tattici (esecuzione dei più opportuni interventi colturali) che strategici (scelta delle specie o varietà più idonee a valorizzare ciascun am­biente).

Recent advances in measuring, estimating, and forecasting grapevine yield and quality

Grapevine yield and fruit quality are two major drivers of input allocation and, ultimately, revenue for grape producers. Because yield and fruit quality vary substantially from year-to-year and within a single block, opportunities exist for optimization via precision management activities that could lead to more profitable and sustainable grape production. Here, we review recent advances in the techniques and technology used to measure, estimate, and forecast grapevine yield and fruit quality. First, we discuss direct “measurement” of yield and quality (i.e. ground-truth data generation), with an emphasis on potential for scalability and automation. Second, we discuss technology and techniques that do not directly measure yield and quality, but use correlated measurements for their estimation.

Toasted Vine-Shoots As An Alternative Enological Tool. Impact On The Sensory Profile Of Tempranillo Wines

The use of toasted vine-shoots as an alternative enological tool to make differentiated wines has generated interest among researchers and wineries. However, the evolution of these wines in bottle and the effect on the sensory profile has not been studied so far.