# Exploring Red Wines from the Drama Region: A Chemical, Sensory, and Terroir Insight
## 3 Results and Discussion
### Physicochemical Parameters of Grapes and Wines
Cultivars with a higher malic acid content typically exhibit lower pH values, contributing to a more acidic taste profile [36]. Regarding the alcohol content, the cultivar Merlot resulted in a wine with the highest values, possibly due to the highest sugar content. In general, the must sugar content was strongly positively correlated (0.870, \(p=0.00\)) with the wine alcohol. Concerning the alcohol content, annual climatic differences can cause significant fluctuations in the alcohol content. Thus, warmer growing seasons promote faster sugar accumulation, leading to higher potential alcohol levels. Cooler seasons may result in slower sugar development, producing wines with a lower alcohol content [34]. Our results reveal that must sugar content is correlated negatively with the TA (\(-0.335\), \(p=0.035\)) and VA (\(-0.346\), \(p=0.029\)) of wine. In general, the must composition affected the wine parameters, as confirmed by the significant correlation coefficients shown in Table 4. Late harvesting was negatively associated with wine pH, whereas the weight of grapes was negatively associated with pH, residual sugars, and malic acid in the wine. Must acidity was associated positively with the TA and VA of wine, whereas must pH was positively associated with the wine pH. On the other hand, YAN was associated positively with wine TA and negatively with wine VA. The previous research indicates that cultivar [37] and pedoclimatic conditions [38], including soil composition and climate, can impact YAN levels in grapes. These environmental factors may also influence grape acidity, suggesting a complex interplay between YAN and TA. High YAN, very-low-pH must, high fermentation temperatures, and oxygen deficiency during the critical yeast growth phase can be considered as factors that promote VA production [39]. Since YAN represents the microorganisms' nitrogen source in the must, it affects their growth. High levels of YANpromote the formation of ethyl acetate and acetic acid, resulting in wines with high volatile acidity [40], whereas low levels promote the formation of sulfur compounds (i.e., hydrogen sulfide) [41]. Since YAN affects the balance of TA and VA, it can be considered a critical factor that affects wine flavor. The data presented in Figure 2 show the chromatic parameters of the examined wines. Location significantly affects absorbance at light wavelengths at 420, 520, and 620 nm and color intensity regardless of the cultivar type. On the other hand, in the case of the Merlot and Cabernet Sauvignon cultivars, color hue is stable among the locations. In general, the chromatic parameter studied showed similar values during the two growing years, regardless of the cultivar type. Generally, Merlot wines had a higher color intensity and lower hue than Cabernet Sauvignon wines but were statistically similar to Agiorgitiko wines. The color intensity of wines increases with an increasing altitude due to increased UV radiation, which, in turn, promotes the synthesis of anthocyanins, flavonoids. and tannins [23]. In our case, a strong negative association (\(-0.700\), \(p=0.000\)) of color hue with altitude but not of color intensity was observed. A significant negative association (\(-0.382\), \(p=0.015\)) is observed between altitude and absorbance at A\({}_{620\text{nm}}\), suggesting that with an increasing altitude exists a decrease in the blue color of the wines. Indeed, lower temperatures and greater diurnal temperature variations are common at higher elevations. Grape ripening may be slowed by these factors, which may alter the anthocyanin content and cause the grape to shift in hue from purple to red tones [23]. Figure 2: Chromatic parameters: (**a**) A\({}_{20\text{nm}}\), A\({}_{520\text{nm}}\), and A\({}_{620\text{nm}}\) and (**b**) color intensity and hue of wines obtained from the cultivars Merlot, Cabernet Sauvignon, and Agiorgitiko grown in different locations. Means are the results of triplicate measurements.