WINETECH Technical Yearbook 2021

The valorisation of the natural grape seeds holds several advantages, the renewability of this resource being key. As a by-product of winemaking, the seeds are readily available and can potentially provide a sustainable and economic product to reduce/eliminate the need for bentonite. SUMMARY Sauvignon blanc and Sémillon juice were fined with grape seed powder and compared to an unfined control and a post- fermentation bentonite treatment. Results

showed that grape seed powder was able to improve the heat stability of the resulting wine significantly and had a relatively small sensory impact with both positive and negative influences. REFERENCES Romanini, E., McRae, J.M., Colangelo, D. & Lambri, M., 2020. First trials to assess the feasibility of grape seed powder (GSP) as a novel and sustainable bentonite alternative. Food Chemistry 305 (March 2019): 125484. https://doi.org/10.1016/j. foodchem.2019.125484.

Romanini, E., McRae, J.M., Bilogrevic, E., Colangelo, D., Gabrielli, M. & Lambri, M., 2021. Use of grape seeds to reduce haze formation in white wines. Food Chemistry 341 (July 2020): 128250. https://doi. org/10.1016/j.foodchem.2020.128250 . McRae, J.M., Barricklow, V., Pocock, K.F. & Smith, P.A., 2018. Predicting protein haze formation in white wines. Australian Journal of Grape and Wine Research 24(4): 504-511. https://doi.org/10.1111/ajgw.12354 . Gombau, J., Nadal, P., Canela, N., Gómez- Alonso, S., García-Romero, E., Smith, P.,

Hermosín-Gutiérrez, I. , Canals, J.M. & Zamora, F., 2019. Measurement of the interaction between mucin and oenological tannins by surface plasmon resonance (SPR); relationship with astringency. Food Chemistry 275: 397-406. https://doi. org/10.1016/j.foodchem.2018.09.075 .

For more information, contact Carien Coetzee at carien@basicwine.co.za.

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