WINETECH Technical Yearbook 2019

sets showing a slight decrease with higher temperature and longer storage times.

Colour Key

Colour Key

FIGURE 1. Heat map of a CB sample set indicating the attributes that have changed with storage, how much they changed (higher or lower), and how the samples are similar based on these attribute changes. FIGURE 1. Heat map of a CB sample set indicating the attributes that have changed with storage, how much they changed (higher or lower), and how the samples are similar based on these attribute changes.

mostly with green attributes) and the T9 samples (‘toasted’, ‘oaky’ and ‘woody’). The attributes used for samples stored at lower temperatures for shorter periods of time were more similar to attributes used to describe the control and were different from attributes used for samples stored at higher temperatures for prolonged periods of time (Figure 1 and 2). The evolution of ‘floral’ and ‘fruity’ notes in the controls was more subtle (variation less extreme) in SB Most interestingly, further statistical analysis made it possible to demonstrate that f each cultivar and regardless of the initial wine sensory profiles, the storage conditions had similar effects on the evolution of the wines (with one exception). In other words, even if the wines were described differently, they changed in a similar pattern. than in CB wines. CB control wines, for most of the sample sets, showed a sharper decline in floral and fresh notes over time and at increased temperatures. SB control wines were more ‘fruity’, ‘floral’ and ‘tropical’ than wines stored at higher temperatures for longer, which were more ‘toasty’, ‘oaky’ and ‘spicy’. This is similar to the results on New Zealand SB (Makhotkina et al ., 2012) and on Spanish white cultivars (Pérez-Coello et al ., 2003). Both the New Zealand and FIGURE 2. Heat map of a SB sample set indicating the attributes that have change with storage, how much they changed (higher or lower), and how the samples are similar b sed on these attribute changes. FIGURE 2. Heat map of a SB sample set indicating the attributes that have changed with storage, how much they changed (higher or lower), and how the samples are similar based on these attribute changes.

as they are descriptive and intuitive. Read horizontally, a sample is described comparative to the control (Figure 1 and 2) – for each attribute, the intensity can be higher, lower, or the same as for the control. Read vertically, we can see how each attribute was different for a certain sample compared to the control. The dendrogram (on the left side), shows how the samples are related to each other and grouped based on distances (similarities). Further statistical analysis showed that all control samples (T0) were very different

from treatments. Treatments were closely associated according to storage time (3 and 9 months). The experienced panel of judges in this study were consistently able to pick up aroma differences in the treated samples from the control. Changes were observed in attributes/ profile, but did not negatively affect the wine aroma for the time period tested (Figure 3). The cont rol sampl es were descr ibed mostly with ‘fruity’ and ‘floral’ attributes, different from the T3 samples (described