Institute for Wine Biotechnology

Investigating the effect of selected non-saccharomyces species on wine ecosystem function and major volatiles

Bagheri, Bahareh; Zambelli, Paolo; Vigentini, Ileana; Bauer, Florian Franz; Setati, Mathabatha Evodia (Frontiers Media, 2018-11-13)

Natural alcoholic fermentation is initiated by a diverse population of several non-Saccharomyces yeast species. However, most of the species progressively die off, leaving only a few strongly fermentative species, mainly ...

Carnitine requires choline to exert physiological effects in saccharomyces cerevisiae

Du Plessis, Michelle; Franken, Jaco; Bauer, Florian F. (Frontiers Media, 2018-07-02)

L-Carnitine is a key metabolite in the energy metabolism of eukaryotic cells, functioning as a shuttling molecule for activated acyl-residues between cellular compartments. In higher eukaryotes this function is essential, ...

Modulation of yeast-derived volatile aromas by oleic acid and sterols

Fairbairn, S.; Ferreira, A. C. Silva; Bauer, F. F. (South African Society for Enology and Viticulture, 2019)

Unsaturated fatty acids and sterols are essential constituents of the yeast plasma membrane. Recently, their contribution to modulating the production of yeast-derived volatile compounds has received significant attention. ...

Nutrient exchange of carbon and nitrogen promotes the formation of stable mutualisms between chlorella sorokiniana and saccharomyces cerevisiae under engineered synthetic growth conditions

Naidoo, Rene K.; Simpson, Zoe F.; Oosthuizen, Jennifer R.; Bauer, Florian F. (Frontiers Media, 2019-04)

Microbial biotechnological processes can be based on single species pure cultures or on multi-species assemblages. While these assemblages can be advantageous by offering more functionalities and more resilience to changing ...

Linking terpene synthases to sesquiterpene metabolism in grapevine flowers

Smit, Samuel Jacobus; Vivier, Melane Alethea; Young, Philip Richard (Frontiers Media, 2019)

Grapevine (Vitis vinifera L.) terpene synthases (VviTPS) are responsible for the biosynthesis of terpenic volatiles. Volatile profiling of nine commercial wine cultivars showed unique cultivar-specific variation in volatile ...

Rapid sensory profiling methods for wine : workflow optimisation for research and industry applications

Brand, Jeanne (Stellenbosch : Stellenbosch University, 2019-04)

ENGLISH ABSTRACT: Descriptive sensory analysis techniques are widely used and trusted methodologies. Due to time and cost constraints, the demand for cost-effective methods for profiling is growing rapidly in food and ...

A microbiological solution to visible wine defects : pinking and protein haze formation

Kufa, Amanda (Stellenbosch : Stellenbosch University, 2019-04)

ENGLISH ABSTRACT: The wine industry is challenged with visible and nonvisible wine defects, which result in profit losses as consumers reject such wines. The clarity and color of the wine are essential to white wine ...

Insights into South African wine consumer behaviour : a mixed methods study

Gevers, Claudia (Stellenbosch : Stellenbosch University, 2019-04)

ENGLISH ABSTRACT: South Africa is not considered a wine drinking nation. Wine is faced by competition, especially from beer and ready-to-drink beverages, for a larger share of the local alcoholic beverage market. Therefore, ...

Linking the phenolic potential of grape berries with polyphenol distribution during wine making : a Sauvignon Blanc case study.

Williams, Davin Lance (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 ...

Exploring consumers’ risk perception in wine retail decision-making : insights for Chenin blanc

Van der Colff, Nadia (Stellenbosch : Stellenbosch University, 2019-04)

ENGLISH ABSTRACT: South Africa is a large wine producing country without a wine-drinking culture. Therefore, the development of the domestic wine market is a priority of the Wine Industry Strategic Exercise (WISE). The ...

Impact of the protease-secreting yeast Metschnikowia pulcherrima IWBT Y1123 on wine properties and response of protease production to nitrogen sources

Snyman, Carla (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 ...

Evaluating the vitamin requirements of wine-related yeasts and the resultant impact on population dynamics and fermentation kinetics

Julies, Jerobiam Marvin (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 ...

Investigating the influence of a wine yeast consortium on population dynamics, alcoholic and malolactic fermentation

Janse van Rensburg, Philippe Jacques (Stellenbosch : Stellenbosch University, 2018-12)

ENGLISH ABSTRACT: Non-Saccharomyces (NS) starter cultures of species such as Metschnikowia pulcherrima, Torulaspora delbrueckii, Pichia kluyveri and Lachancea thermotolerans, have received attention for their desirable ...

The impact of UV-light on grapevine berry and wine metabolites.

Honeth, Chandré (Stellenbosch : Stellenbosch University, 2018-12)

ENGLISH ABSTRACT: Within their natural environments, plants are constantly challenged by a multitude of stress factors and have therefore evolved different adaptive strategies to mitigate potential damage as well as to ...

A survey of the YAN status of South African grape juices and exploration of multivariate data analysis techniques for spectrometric calibration and cultivar discrimination purposes.

Petrovic, Gabriella (Stellenbosch : Stellenbosch University, 2018-12)

ENGLISH ABSTRACT: Yeast assimilable nitrogen (YAN) has been identified as one of the main drivers of wine quality, influencing the production of various aromas and ensuring a successful fermentation to dryness. Due to the ...

Effect of foliar Nitrogen and Sulphur spraying on white wine composition ( Vitis vinifera L.cv. Chenin Blanc and Sauvignon Blanc)

Bruwer, Freda Aléta (Stellenbosch : Stellenbosch University, 2018-12)

ENGLISH ABSTRACT: Chenin Blanc and Sauvignon Blanc, as the most planted wine cultivars in South Africa, are of great interest to researchers worldwide, due to its increased high wine quality. Wine quality is interlinked ...