# Influence of Region on Sensory and Chemical Profiles of Pennsylvania Gruner Veltliner Wines
## 3 Results and Discussion
### Relating Sensory and Instrumental Data  
Significant sensory and wine instrumental variables were correlated using [PERSON]'s correlation coefficient. Statistical correlations may indicate potential relationships between instrumental and sensory data. Examining these correlations does not prove causality, however, it can give insight into which relationships should be further studied and which ones may be causal. Significant linear correlations between variables for both years are shown in Figure 3. Year 1 (Figure 3A) resulted in fewer significant linear correlations between sensory attributes and instrumental variables than Year 2 (\(n=122\) vs. \(n=244\)), possibly because there were fewer significant differences between wines in sensory attributes and aroma compounds in Year 1. For both years, yellow color was positively correlated with \(b^{*}\) values (Year 1: \(r(16)=0.88\), \(p=1.26\times 10^{-6}\); Year 2: \(r(13)=0.64\), \(p=1.378\times 10^{-2}\)) and negatively with \(a^{*}\) values (Year 1: \(r(16)=-0.89\), \(p=7.23\times 10^{-7}\); Year 2: \(r(13)=-0.56\), \(p=0.04\)). Higher \(b^{*}\) values indicate a sample is more yellow in color, so \(b^{*}\) and yellow color correlation was expected. \(a^{*}\) values were negative for the samples, which indicate a sample is greener and less red, and for white wines a negative \(a^{*}\) value is not unexpected since there is limited skin contact to give a more orange or red color to wines. The strong positive thiol aroma and flavor correlation was consistent in both years as well (Year 1: \(r(16)=0.75\), \(p=3.1\times 10^{-4}\); Year 2: \(r(13)=0.89\), \(p=1.36\times 10^{-5}\)). Sour taste was positively correlated with TA values and negatively with pH values in both years. This was also expected as lower pH values indicate higher acidity, while higher TA values also indicate higher acidity. There were a number of significant correlations that were only found in the Year 1 data (Figure 3A). In Year 1, thiol aroma, i.e., the aroma associated with 4 MMP (Table 1), was positively correlated to (+)-catechin (\(r(16)=0.68\), \(p=0.002\)) and free SO\({}_{2}\) (\(r(16)=0.59\), \(p=0.01\)). It is possible that sulfur acted as an antioxidant and prevented oxidation of thiols and subsequent loss of thiol aroma. Research has shown that additions of SO\({}_{2}\) can prevent loss of thiols in the presence of (+)-catechin in model wine [(43)]. Work by Saucier and Waterhouse has also found (+)-catechin to have a synergistic effect in combination with SO\({}_{2}\) in preventing oxidation in model wine [(48)]. Sulfur aroma, i.e., the aroma associated with the smell of potassium metabisulfite (Table 1), was also positively correlated with free SO\({}_{2}\) (\(r(16)=0.49\), \(p=0.037\)). This was expected, as aroma of SO\({}_{2}\) is detected when a high proportion of SO\({}_{2}\) is in the free form. Figure 3: Significant correlation (\(p<0.05\)) of sensory and chemistry parameters for Year 1 (**A**) and Year 2 (**B**) Grünner V. wines. Positive correlations are shown in red shades while negative correlations are shown in blue. There were several significant negative correlations between sensory and instrumental variables in Year 1 (Figure 3A). Sulfur aroma was negatively correlated with multiple esters, including ethyl hexanoate, hexyl acetate, 2-hexen-1-ol acetate, ethyl octanoate, and ethyl decanoate. Sulfur dioxide can bind with carbonyl compounds and reduce concentrations of aroma compounds such as \(\beta\)-damascenone or acetaldehyde [49]; however, in the case of volatile esters, additions of sulfur dioxide can retain ester concentrations after three months of aging [50], so it is likely this negative correlation is not causal. Gallic acid was negatively correlated with sour taste (\(r(16)=-0.54\), \(p=0.021\)) and positively correlated with pH (\(r(16)=0.62\), \(p=0.006\)).