Institute for Wine Biotechnology

Modulation of wine flavor using hanseniaspora uvarum in combination with different saccharomyces cerevisiae, lactic acid bacteria strains and malolactic fermentation strategies

Du Plessis, Heinrich; Du Toit, Maret; Nieuwoudt, Helene; Van Der Rijst, Marieta; Hoff, Justin; Jolly, Neil (MDPI, 2019-07-20)

Hanseniaspora uvarum is one of the predominant non-Saccharomyces yeast species found on grapes and in juice, but its effect on lactic acid bacteria (LAB) growth and wine flavor has not been extensively studied. Therefore, ...

Non-Saccharomyces yeast and lactic acid bacteria in Co-inoculated fermentations with two Saccharomyces cerevisiae yeast strains : a strategy to improve the phenolic content of Syrah wine

Minnaar, P. P.; Du Plessis, H. W.; Jolly, N. P.; Van Der Rijst, M.; Du Toit, M. (MDPI, 2019)

Syrah must was co-inoculated with mixed cultures of Saccharomyces + O. oeni/Lb. plantarum and Saccharomyces + non-Saccharomyces + O. oeni/Lb. plantarum to evaluate the effect on phenolics and sensory attributes. Reference ...

Deconstructing wine grape cell walls with enzymes during winemaking : new insights from glycan microarray technology

Gao, Yu; Zietsman, Anscha J. J.; Vivier, Melane A.; Moore, John P. (MDPI, 2019-01-04)

Enzyme-aid maceration is carried out in most modern winemaking industries with a range of positive impacts on wine production. However, inconsistencies in enzyme efficiency are an issue complicated by unclear targets ...

Functional analysis of candidate terpenoid biosynthetic genes isolated from grapevine

Bezuidenhout, Ilse-Marie (Stellenbosch : Stellenbosch University, 2021-03)

ENGLISH ABSTRACT: Terpenoids are a group of compounds found in various organisms, with diverse functions, and can be broadly grouped into primary or specialised (secondary) metabolites. This compound diversity is achieved ...

In-Line Monitoring of Red Wine Fermentation

Lambrecht, Kiera Nareece (Stellenbosch : Stellenbosch University, 2021-03)

ENGLISH ABSTRACT: Phenolic compounds may only account for a small percentage of the final composition of a finished red wine but are vital to its sensory attributes. During red wine making, extraction of ...

Cell wall profiling of tobacco leaves and grapes in the context of Botrytis cinerea infection

Weiller, Florent (Stellenbosch : Stellenbosch University, 2021-03)

ENGLISH ABSTRACT: The plant cell wall has been shown to be at the centre of plant-biotic stress interactions. In the case of a pathogen encounter (e.g. fungi), the cell wall acts as the second barrier after the cuticle to ...

Is there a link between coffee aroma and the level of furanmethanethiol (FMT) in pinotage wines

Garrido-Banuelos, G.; Buica, A. S. (South African Society for Enology and Viticulture, 2020)

Over the years, Pinotage has found its way into the South African and international market. Producers have used the flavour potential of this “original” South African grape to produce different wine styles, one of them ...

Investigating the concept of South African old vine Chenin blanc

Mafata, M.; Brand, J.; Panzeri, V.; Buica, A. S. (South African Society for Enology and Viticulture, 2020)

Although South African vineyards are still young by European standards, there is a belief in the industry that vines aged 35 or more years produce grapes and wines with specific characteristics (“old vine wines”). The aim ...

Plant immunity is compartmentalized and specialized in roots

Chuberre, Coralie; Plancot, Barbara; Driouich, Azeddine; Moore, John P.; Bardor, Muriel; Gugi, Bruno; Vicre, Maïte (Frontiers Media, 2018)

Roots are important organs for plant survival. In recent years, clear differences between roots and shoots in their respective plant defense strategies have been highlighted. Some putative gene markers of defense responses ...

Sequence-function relationships of the Vitis vinifera L. terpene synthase (VviTPS) family towards understanding the grapevine flower volatilome

Smit, Jacobus Samuel (Stellenbosch : Stellenbosch University, 2020-04)

ENGLISH ABSTRACT: Terpenes are ubiquitous to plants and represent the most diverse class of natural products. More than 50 000 terpenes have been described in nature with the enzymes involved in their ...

Insights into South African sparkling wine : a sensory and consumer study

Mokonotela, Tshepo Tshiamo (Stellenbosch : Stellenbosch University, 2020-03)

ENGLISH ABSTRACT: To be locally and internationally competitive, the South African wine industry needs to understand consumers’ preferences and purchase motivations. It is especially the sparkling wine category Méthode ...

Impact of complex yeast nutrient products on selected non Saccharomyces yeasts

Beukes, Louisa (Stellenbosch : Stellenbosch University, 2020-03-31)

ENGLISH ABSTRACT: In recent years there has been a growing interest in non-Saccharomyces yeasts for winemaking due to their ability to produce more complex wines. These yeasts, considered weak fermenters, are used in ...

Sorting in combination with quality scoring : a tool for industry professionals to identify drivers of wine quality rapidly

Brand, J.; Kidd, M.; Van Antwerpen, L.; Valentin, D.; Naes, T.; Nieuwoudt, Helene (South African Society for Enology and Viticulture, 2018)

Quality plays an important role in the criteria directing wine product development. The evaluation of sensory characteristics associated with wine quality, as perceived by industry professionals, is therefore important. ...

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

Bagheri, Bahareh; Zambelli, Paolo; Vigentini, Ileana; Bauer, Florian; 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 (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, Florian (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 (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 ...