WINETECH Technical Yearbook 2021

to characterise each sample (Valentin et al. , 2012). CATA aroma terms used in this study were selected from the South African Chenin blanc aroma wheel. The results were compiled first in a frequency of citation table and subsequently submitted to multivariate analysis. For the first season (2017), there were few differences in terms of number and type of descriptors used for the wines: 25- 30 for the industry professionals, while the analytical panel used all 40 terms in the list. The most cited attributes overall were ‘passion fruit’ (professionals) and ‘pineapple’ (analytical panel). ‘Passion fruit’ was also used by the analytical panel for all the wines; ‘guava’ and ‘grapefruit’ also appeared in the top five across all systems. Looking at the industry professionals’ list, ‘pineapple’ was frequently used across all systems, together with ‘lemon’, ‘melon’ and ‘peach’. This was already an indication that the wines might be quite similar across treatments. The configuration resulting from the multivariate analyses demonstrated what was already suggested by the frequency data, all samples overlapping except for Lyre wines. These wines were described by the professionals with ‘passion fruit’ and ‘grapefruit’ (common attributes for all wines), but also ‘vanilla’, ‘baked bread’

and ‘stewed fruit’ (less common across the systems). The analytical panel described only the Lyre wines with ‘fynbos’ and ‘oak’. In 2018, only the analytical panel tasted the wines. This time, 36 terms were used to describe the wines and again ‘pineapple’ was the most cited. Overall, three of the top five attributes were common to all treatments for both years – ‘pineapple’, ‘apple’ and ‘passion fruit’. However, for this vintage there were some differences resulting from the multivariate analysis configuration: Lyre and Santorini wines were associated with ‘floral’, ‘pear’ and ‘dusty’; T-frame wines had the most (overall) common attributes ‘orange’, ‘peach’, ‘apple’, ‘lemon’ and ‘passion fruit’; Ballerina wines were characterised by ‘marmalade’, ‘fynbos’ and ‘tobacco’; and Smart-Dyson wines were ‘spicy’, ‘caramel’, ‘papaya’ and ‘sweet associated’. QUALITY EVALUATION The industry professionals evaluated the wines only in 2017; they were instructed to use the 20-point scale and judge the colour out of 3, aroma out of 7, and taste out of 10. From a quality perspective, the aromas of all wines were judged to be similar. For aroma, only Santorini wines were statistically lower than the rest (average of 4.5 out of 7), while Lyre wines were

evaluated as the highest (average of 5 out of 7). There were no differences for colour and all wines scored close to 3. Santorini wines were once more evaluated as the lowest for taste; all the other wines were scored similar to each other. Overall, Santorini wines were the lowest scoring (12 out of 20, statistically lower than the rest). Lyre and T-frame scored the highest (approximately 14 out of 20). TAKE-HOME MESSAGE Even though a lack of differences between systems can be considered a negative result, in the case of the current study it is a positive one. It means that the trellising systems did not affect the wines extensively. In this case, the choice can be a system that results in increased yield without compromising the aroma. Chemically, the wines were not identical, but the overall composition did not differ significantly. A similar trend was observed for the aroma data of 2017 and 2018; all wines were described by fruity notes which relate to esters and thiols. The floral notes mentioned could be associated with other aromatic chemical compounds (terpenes), not analysed in the study. The aroma quality was also not compro­ mised. The results for the other two aspects of quality are somewhat different; colour,

taste and mouthfeel are mainly related to non-volatile compounds, and these results will be presented in Part 3 of this series. SUMMARY Are wine aroma characteristics influenced by different trellising systems? Despite the importance of trellising systems in viticulture, little work has been done on the specific effect of various trellising systems on the wine’s chemical and senso- rial characteristics. To answer this, it is of interest to compare wines of various trellis systems from a chemical and sensorial point of view, under controlled conditions.

For more information, contact Astrid Buica at astrid.buica@gmail.com.

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