WINETECH Technical Yearbook 2020

CONCLUSIONS Wines in the respective seasons corres­ ponded with sequential harvest using a berry physiological indicator as wines were classified as fresh, green characters in 2010/2011 and prune and raisin characters in 2011/2012. Wines from the STD treatment were consistently rated as having higher satin properties in and after expectoration. REFERENCES Bajec, M. R. & Pickering, G. J. 2008. Astringency: mechanisms and perception. Critical Reviews in Food Science and Nutrition , 48, 858-875. Cheynier, V., Dueñas-Paton, M., Salas, E., Maury, C, Jean-Marc Souquet, J., Sarni-Manchado, P. & Fulcrand, H. 2006. Structure and properties of wine pigments

and tannins. American Journal of Enology and Viticulture 57, 298-305. Deloire, A.J. 2011. The concept of sugar loading. Wynboer , January, 93-95. Kennedy, J.A., Ferrier, J., Harbertson, J.F. & Gachons, C.P.D. 2006. Analysis of tannins in red wine using multiple methods: Correlation with perceived astringency. American Journal of Enology and Viticulture 57, 481-485. Ma, W., Guo, A., Zhang, Y., Wang, H., Liu, Y. and Li, H. 2014. A review on astringency and bitterness perception of tannins in wine. Trends in Food Science & Technology 40, 6-19. Mercurio, M.D. & Smith, P.A. 2008. Tannin quantification in red grapes and wine: Comparison of polysaccharide- and protein-based tannin precipitation

techniques and their ability to model wine astringency. Journal of Agricultural and Food Chemistry 56, 5528-5537. Nell, M. 2015. Sensory characterisation of several red cultivar (Vitis vinifera L.) wines, using berry sugar accumulation as a physiological indicator and sequential harvest. MScAgric thesis, Stellenbosch University. Oberholster, A., Francis, I., Iland, P. & Waters, E. 2009. Mouthfeel of wines made with and without pomace contact and added anthocyanins. Australian Journal of Grape and Wine Research 15, 59-69. Ott, R.L. 1998. An introduction to statistical methods and data analysis. Duxbury Press, Belmont, California. Ristic, R., Downey, M.O., Illand, P.G., Bindon, K., Francis, I.L., Herderich, M.,

Robinson, S. 2007. Exclusion of sunlight from Shiraz grapes alters wine colour, tannin and sensory properties. Australian Journal of Grape and Wine Research 13, 53-65. Shapiro, S.S. & Wilk, M.B. 1965. An analysis of variance test for normality (complete samples). Biometrika 52, 591- 611. Vidal, S., Francis, L., Guyot, S., Marnet, N., Kwiatkowski, M. & Gawel, R. 2003. The mouth-feel properties of grape and apple proanthocyanidins in a wine-like medium. Journal of the Science of Food and Agriculture 83, 6, 564-573.

For more information, contact Erna Blancquaert at ewitbooi@sun.ac.za.

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