WINETECH Technical Yearbook 2020

REFERENCES Jolly, N.P., Varela, C. & Pretorius, I.S. 2014. Not your ordinary yeast: Non- Saccharo- myces yeasts in wine production uncov- ered. FEMS Yeast Research 14, 215-237. Jolly, N.P., Augustyn, O.P.H. & Pretorius, I.S. 2003. The occurrence of non- Saccharomyces cerevisiae yeast species over three vintages in four vineyards and grape musts from four production regions of the Western Cape, South Africa. South African Journal of Enology and Viticulture 24, 35-42. Brežná, B., Ženišová, K., Chaovanová, K., Chebeňová, V., Kraková, L., Kuchta, T. & Pangallo, D. 2010. Evaluation of fungal and yeast diversity in Slovakian wine- related microbial communities. Antonie van Leeuwenhoek 98, 519-529. Bedford, C.L. 1942. A taxonomic study of the genus Hansenula. Mycologia 34, 628-649. Prior, K.J., Bauer, F.F. & Divol, B. 2019. The utilization of nitrogenous compounds by commercial non- Saccharomyces yeasts associated with wine. Food Microbiology 79, 75-84.

Padilla, B., Gil, J.V. & Manzanares, P. 2016. Past and future of non- Saccharomyces yeasts: From spoilage microorganisms to biotechnological tools for improving wine aroma complexity. Frontiers in Microbiology 7, 411. Escribano, R., González-Arenzana, L., Gar- ijo, P., Berlanas, C., López-Alfaro, I., López, R., Gutiérrez, A.R. & Santamaría, P. 2017. Screening of enzymatic activities within different enological non- Saccharomyces yeasts. Journal of Food Science and Tech- nology 54, 1555-1564. Benito, A., Calderón, F. & Benito, S. 2019. The influence of non- Saccharomyces species on wine fermentation quality parameters. Fermentation 5, 54. Morata, A., Escott, C., Bañuelos, A., Loira, I., De Fresno, J.M., González, C. & Suárez- Lepe, J.A. 2020. Contribution of non- Saccharomyces yeasts to wine freshness – a review. Biomolecules 10, 34.

imparts flowery, rose and fruity aromas in wine) in pure culture and in sequential inoculation with S. cerevisiae (Prior et al ., 2019) . It also produces about 10% more ethyl octanoate (which imparts sweet, ripe fruit, pear and pineapple aromas in wine) than S. cerevisiae (Benito et al ., 2019) . Sequential inoculation of Riesling with S. cerevisiae increases overall impression of peach/apricot character (Benito et al ., 2015), while the volatile thiols released by this yeast enhance grapefruit and passion fruit aromas in Sauvignon blanc (Morata et al ., 2020). CONCLUSION Pichia kluyveri Frootzen ® from Chr. Hansen (www.chr-hansen.com) is the only commercial product available. It is supplied as a frozen product used for direct inoculation into grape must without any rehydration. This yeast is especially recommended for Sauvignon blanc, Riesling and Chardonnay wines (Benito et al ., 2015; Morata et al ., 2020).

Nutt, J. 2018. Multispecies interactions in a simplified wine yeast consortium. MSc Thesis, Stellenbosch University, South Africa. Available on https://scholar.sun. ac.za/handle/10019.1/103538. Mestre Furlani, M.V., Maturano, Y.P., Combina, M., Mercado, L.A., Toro, M.E. & Vazquez, F. 2017. Selection of non- Saccharomyces yeasts to be used in grape musts with high alcoholic potential: A strategy to obtain wines with reduced ethanol content. FEMS Yeast Research 17, foc010. Benito, S., Hoffmann, T., Laier, M., Loch - bühler, B., Schüttler, A., Ebert, K., Fritsch, S., Röcker, J. & Rauhut, D. 2015. Effect on quality and composition of Riesling wines fermented by sequential inoculation with non- Saccharomyces and Saccharomyces cerevisiae. European Food Research and Technology 24, 707-717. Anfang, N., Brajkovich, M. & Goddard, M.R. 2009. Co-fermentation with Pichia kluyveri increases varietal thiol concentrations in Sauvignon blanc. Australian Journal of Grape and Wine Research 15, 1-8.

For more information, contact Evodia Setati at setati@sun.ac.za.

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