Project Number
WW ASB 17-01
Project title
Investigating thiol stability in commercial Chenin blanc wines using chemical analysis and sensory evaluation: a comparison with Sauvignon blanc
Project leader
Buica, A S
Institution
Stellenbosch University. Department of Viticulture and Oenology
Team members
Brand, J
Stander, M
Taylor, M
Mokwena, L
Kidd, M
Objectives & Rationale
The availability of data concerning the stability of aroma and aroma compounds is dependent on the cultivar and compounds of interest. For Chenin blanc some hypotheses can be proposed based on the research done on Sauvignon Blanc. The work was done on New Zealand and the evaluation was only chemical. While there is other work published that is of general relevance, the research usually deals with the overall aroma stability, especially as affected by oxygen exposure during storage. There is still a dire need to elucidate the fate of thiols in Chenin Blanc and the effect storage conditions have both from a chemical and sensory point of view.
Methods
We have selected Chenin Blanc and Sauvignon Blanc wines from six wineries. The wines were stored for 3 years and 9 months in various conditions – 15 and 25°C (controlled environment), and room conditions (temperature not controlled). A control set was also included (no storage). The wines were moved to -4°C until further evaluation. The approach was both targeted and untargeted focusing on thiols and antioxidants (glutathione, SO2, phenolics). The sensory evaluation was done using Pivot Profiling, a method that employs a reference (in this case, the control, time 0) and compares the rest of the samples in the set to it while generating a series of attributes for both the reference and the samples.
Key Results
Time played the most important role during storage, regardless of the storage temperature.
Conclusion/Discussion
Based on the sensory evaluation, wines stored at higher temperatures for longer were perceived as more toasty, woody, oak and honey. Those stored at lower temperature for shorter period were perceived as floral and tropical. Correspondence Analysis showed that control (time 0) samples were very different from treatments.
Articles
Mpho Mafata, Jeanne Brand, Valeria Panzeri, Martin Kidd, Astrid Buica, A multivariate approach to evaluating the chemical and sensorial evolution of South African Sauvignon Blanc and Chenin Blanc wines under different bottle storage conditions, Food Research International, Volume 125, 2019, 108515, ISSN 0963-9969, https://doi.org/10.1016/j.foodres.2019.108515
Astrid Buica, Mpo Mafata, Valeria Panzeri and Jeanne Brand. Stability of young Chenin blanc and Sauvignon blanc wine during storage (Part 1): Chemical evaluation, WineLand Magazine
Astrid Buica, Mpo Mafata, Valeria Panzeri and Jeanne Brand. Stability of young Chenin blanc and Sauvignon blanc wine during storage (Part 2): Sensory aspects. WineLand Magazine