WINETECH Technical Yearbook 2019

need to be evaluated under industrial wine production conditions. ACKNOWLEDGEMENTS The authors wish to thank the Agricultural Research Council (ARC) and University of the Western Cape (UWC) for the infrastructure and/or financial support; Anchor Oenology and the NRF/THRIP for financial support; as well as the Wine Technology Subdivision for technical support. REFERENCES Bovo, B., Carlot, M., Fontana, F., Lombardi, A., Soligo, S., Giacomini, A. & Corich, V., 2015. Outlining a selection procedure for Saccharomyces cerevisiae isolated from grape marc to improve fermentation process and distillate quality. Food Microbiology 46, 573-581. Coetzee, C. & Du Toit, W. J., 2012. A comprehensive review on Sauvignon blanc aroma with a focus on certain positive volatile thiols. Food Research International 45, 287-298. Du Toit, M. & Pretorius, I.S., 2000. Microbial spoilage and preservation of wine: Using weapons from nature’s own arsenal – a review. South African Journal of Enology and Viticulture 21, 74-96. Harsch, M.J., Benkwitz, F., Frost, A., Colonna-

Ceccaldi, B., Garner, R.C. & Salmon, J.M., 2013. New precursor of 3-mercaptohexan- 1-ol in grape juice: Thiol-forming potential and kinetics during early stages of must fermentation. Journal of Agricultural and Food Chemistry 61, 3703. Hart, R., Jolly, N., Mohamed, G., Booyse, M. & Ndimba, B., 2016. Characterisation of Saccharomyces cerevisiae hybrid yeasts selected for low volatile acidity formation and the production of aromatic Sauvignon blanc wine. African Journal of Biotechnology 15, 2068-2081. Hart, R.S., Ndimba, B.K. & Jolly, N.P., 2017. Characterisation of thiol-releasing and lower volatile acidity forming intra-genus hybrid yeast strains for Sauvignon blanc wine. South African Journal of Enology and Viticulture 38(2), 144-155. Holt, S., Cordente, A.G., Williams, S.J., Capone, D.L., Jitjaroen, W., Menz, I.R., Curtin, C. & Anderson, P.A., 2011. Engineering Saccharomyces cerev i s i ae to re l ease 3-mercaptohexan-1-ol during fermentation through overexpression of an S. cerevisiae gene, STR3, for improvement of wine aroma. Applied and Environmental Microbiology 77, 3626-3632. King, E.S., 2010. The modulation of Sauvignon blanc wine aroma through control of primary

fermentation. PhD thesis, The School of Agriculture, Food and Wine, University of Adelaide, Adelaide SA, 5005, Australia. Pinu, F.R., Jouanneau, S., Nicolau, L., Gardner, R.C. & Villas-Boas, S.G., 2012. Concentrations of the volatile thiol 3-mercaptohexanol in Sauvignon blanc wines: No correlation with juice precursors. American Journal of Enology and Viticulture 63, 407-412. Roland, A., Schneider, R., Razungles, A. & Cavelier, F., 2011. Varietal thiols in wine: Di scovery, ana l ys i s and appl i cat ions . Chemical Reviews 22, 7355-7376. Swiegers, J., Bartowsky, E., Henschke, P. & Pretorius, I., 2005. Yeast and bacterial modulation of wine aroma and flavour. Australian Journal of Grape and Wine Research 11, 139-173. Swiegers, J.H., Capone, D.L., Pardon, K.H., Elsey, G.M., Sefton, M.A., Francis, I.L. & Pretorius, I.S., 2007a. Engineering volatile thiol release in Saccharomyces cerevisiae for improved wine aroma. Yeast 24, 561-574. Swiegers, J.H., Francis, I.L., Herderich, M.J. & Pretorius, I.S., 2006a. Meeting consumer expectations through management in vineyard and winery: The choice of yeast for fermentation offers great potential to adjust the aroma of Sauvignon blanc wine.

Australian and New Zealand Wine Industry Journal 21, 34-42. Swiegers, J.H., King, E., Travis, B., Francis, L. & Pretorius, I.S., 2007b. Enhancement of Sauvignon blanc wine aroma through yeast combinations. Online: http://www. wineland.co.za/technical/enhancement-of- sauvignon-blanc-wine-aroma-through-yeast- combinations (accessed on 27 May 2016). Ugliano, M., Kwiatkowski, M.J., Travis, B., Francis, I.L., Waters, E.J., Herderich, M.J. & Pretorius, I.S., 2009. Post-bottling management of oxygen to reduce off-flavour formation and optimise wine style. Online: http://www.newworldwinemaker.com/pdf/ AWRI_report_post-bottling_management. pdf (accessed on 31 July 2017). Van Wyngaard, E., 2013. Volatiles playing an important role in South African Sauvignon blanc wines. MSc thesis, Stellenbosch University, Private Bag X1, 7602, Matieland (Stellenbosch), South Africa. Vilela-Moura, A., Schuller, D., Mendes- Faia, A., Silva, R.D., Chaves, S.R., Sousa, M.J. & Côrte-Real, M., 2011. The impact of acetate metabolism on yeast fermentative performance and wine quality: Reduction of volatile acidity of grape musts and wines. Applied Microbiology and Biotechnology 89, 271-280.

– For more information, contact Rodney Hart at hartr@arc.agric.za.