Subject
Now showing items 1-17 of 17
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The deletion and overexpression of two esterase genes, IAH1 and TIP1, in Saccharomyces cerevisiae to determine their effects on the aroma and flavour of wine and brandy
(Stellenbosch : Stellenbosch University, 2002-12)ENGLISH ABSTRACT: No single chemical constituent can be accredited with giving wine and brandy their overall aroma and flavour. The aroma and flavour of wine and brandy are rather attributed to a number of chemical ... -
Evaluating the impact of yeast co-inoculation on individual yeast metabolism and wine composition
(Stellenbosch : Stellenbosch University, 2014-12)ENGLISH ABSTRACT: The use of non-Saccharomyces yeasts together with Saccharomyces cerevisiae in mixed starter cultures has become an accepted oenological tool to enhance the organoleptic properties of wine. Recent studies ... -
Evaluating the vitamin requirements of wine-related yeasts and the resultant impact on population dynamics and fermentation kinetics
(Stellenbosch : Stellenbosch University, 2019-04)ENGLISH ABSTRACT: Within the vineyard environment, grape berries serve as a habitat to various microorganisms including bacteria, filamentous fungi and yeasts, of which some play distinct roles in winemaking. Studies on ... -
The evaluation of bacteriocins and enzymes for biopreservation of wine
(Stellenbosch : Stellenbosch University, 2002-03)ENGLISH ABSTRACT: The winemaking process involves a number of microorganisms, each with its own role. Yeasts are responsible for the alcoholic fermentation, the lactic acid bacteria (LAB) are Gram-positive bacteria ... -
Extracellular acid proteases of wine microorganisms : gene identification, activity characterization and impact on wine
(Stellenbosch : Stellenbosch University, 2012-03)ENGLISH ABSTRACT: Non-Saccharomyces yeasts of oenological origin have previously been associated with spoilage or regarded as undesired yeasts in wine. However, these yeasts have recently come under investigation for their ... -
Impact of the protease-secreting yeast Metschnikowia pulcherrima IWBT Y1123 on wine properties and response of protease production to nitrogen sources
(Stellenbosch : Stellenbosch University, 2019-04)ENGLISH ABSTRACT: Yeast of oenological origin belong to various genera and harbour unique metabolic properties that may significantly impact aspects of wine processing and composition. Extracellular aspartic proteases, and ... -
Influence of winemaking practices on the chemical characteristics of winery wastewater and the water usages of wineries.
(Stellenbosch : Stellenbosch University, 2015-04)ENGLISH ABSTRACT: The production of wine globally has increased over the past years, increasing the volume of water used and wastewater generated for every litre of wine produced. In the past, the small volumes of winery ... -
Investigating the impact of sulphur dioxide on Brettanomyces bruxellensis at a molecular and cellular level
(Stellenbosch : Stellenbosch University, 2012-03)ENGLISH ABSTRACT: The yeast Brettanomyces was isolated from beer in 1904 and associated with wine thereafter. A sporulating form, Dekkera, was discovered later. Brettanomyces bruxellensis produces high levels of volatile ... -
Die invloed van bemesting en lowerbestuur op die kaliuminhoud en pH van Cabernet sap en wyn
(Stellenbosch : Stellenbosch University, 2002-03)ENGLISH ABSTRACT: In an attempt to reduce the pH of juice and wine, different fertiliser applications and canopy management practices were evaluated in a field trial. Fertiliser treatments consisted of no, CaS04, Ca(OH)2, ... -
Linking the phenolic potential of grape berries with polyphenol distribution during wine making : a Sauvignon Blanc case study.
(Stellenbosch : Stellenbosch University, 2019-04)ENGLISH ABSTRACT: The focus of this study was the phenolic potentials of grape and wine matrices of Sauvignon Blanc produced in either a high or low light microclimate. Phenolic compounds are important in grapes due to ... -
Manipulating the levels of ethyl acetate and isoamyl acetate formation during the production of wine and brandy
(Stellenbosch : Stellenbosch University, 2002-12)ENGLISH ABSTRACT: The production of wine is a complex process, which involves the conversion of sugar in grape must to ethanol, carbon dioxide and other byproducts. The principal organism in winemaking is yeast, of which ... -
Molecular typing of wine yeasts : evaluation of typing techniques and establishment of a database
(Stellenbosch : Stellenbosch University, 2012-03)ENGLISH ABSTRACT: The yeast species, Saccharomyces cerevisiae and S. bayanus are well known for the key role they play during alcoholic fermentation in both wine and beer industries. These yeasts are available in pure ... -
Multispecies interactions in a simplified wine yeast consortium
(Stellenbosch : Stellenbosch University, 2018-03)ENGLISH ABSTRACT: Over the last two decades various studies have evaluated the impact of non-Saccharomyces (NS) yeasts on alcoholic fermentation of wine, the chemical imprint they leave in the wine and how this affects ... -
Some aroma compounds of importance to the quality of Ferdinand de Lesseps and Kerner wines
(Stellenbosch : Stellenbosch University, 2000-03)ENGLISH ABSTRACT: Ferdinand de Lesseps grapes have a distinctive fruity varietal character and were often used judiciously by wine-makers to enhance the fruity bouquet of some white table wines. Ferdinand de Lesseps ... -
Stationary phase-specific expression of dominant flocculation genes for controlled flocculation of yeast
(Stellenbosch : Stellenbosch University, 2003-04)ENGLISH ABSTRACT: Flocculation can be defined as the asexual aggregation of yeast cells in a liquid environment. This aggregation of cells, also referred to as "floc formation", will in most cases lead to rapid settling ... -
Stress, fermentation performance and aroma production by yeast
(Stellenbosch : Stellenbosch University, 2012-03)ENGLISH ABSTRACT: Yeast strains contend with numerous stresses during winemaking. An inability to perceive and initiate the physiological changes needed to adapt to stress, has been linked to slow or incomplete (residual ... -
The transformation of wine yeasts with glucanase, xylanase and pectinase genes for improved clarification and filterability of wine
(Stellenbosch : Stellenbosch University, 2003-03)ENGLISH ABSTRACT: Cellulose is by far the most abundant carbohydrate available from plant biomass. These biopolymers are therefore an important renewable source of food, fuels and chemicals. Cellulose is embedded in a ...
