## 3 Results and Discussion
### Effect of the Ca, Si and Ca + Si foliar Treatments on Must Volatile Composition
\begin{table}
\begin{tabular}{c c c c c} \hline  & **Control** & **Ca** & **Si** & **Ca + Si** \\ \hline Weight of 100 berries (g) & 235.30 \(\pm\) 25.45 b & 183.03 \(\pm\) 33.68 a & 222.00 \(\pm\) 19.29 ab & 239.63 \(\pm\) 0.60 b \\ \({}^{\circ}\)Brix & 22.80 \(\pm\) 1.73 a & 22.53 \(\pm\) 1.10 a & 24.83 \(\pm\) 1.76 a & 24.00 \(\pm\) 1.11 a \\ Probable alcohol (\% \(\
u\)/\(\
u\)) & 13.33 \(\pm\) 1.18 a & 13.13 \(\pm\) 0.76 a & 14.72 \(\pm\) 1.22 a & 14.14 \(\pm\) 0.77 a \\ Glucose + Fructose (g/L) & 231.95 \(\pm\) 19.45 a & 232.52 \(\pm\) 11.04 a & 265.52 \(\pm\) 23.85 a & 249.23 \(\pm\) 19.62 a \\ Glucose (g/L) & 116.27 \(\pm\) 10.39 a & 115.63 \(\pm\) 5.28 a & 130.83 \(\pm\) 11.32 a & 124.31 \(\pm\) 1048 a \\ Fructose (g/L) & 115.68 \(\pm\) 9.09 a & 111.68 \(\pm\) 9.22 a & 133.02 \(\pm\) 31.74 b & 118.19 \(\pm\) 16.90 a \\ pH & 3.53 \(\pm\) 0.14 a & 3.73 \(\pm\) 0.14 a & 3.61 \(\pm\) 0.2 a & 3.68 \(\pm\) 0.24 a \\ Total acidity (g/L) \({}^{\star}\) & 5.23 \(\pm\) 0.89 a & 4.72 \(\pm\) 0.16 a & 4.95 \(\pm\) 0.10 a & 5.40 \(\pm\) 0.89 a \\ Tartaric acid (g/L) & 5.02 \(\pm\) 0.37 a & 5.03 \(\pm\) 0.59 a & 4.42 \(\pm\) 0.13 a & 4.48 \(\pm\) 0.86 a \\ Malic acid (g/L) & 2.64 \(\pm\) 0.05 a & 2.21 \(\pm\) 0.26 a & 2.23 \(\pm\) 0.18 a & 2.63 \(\pm\) 0.46 a \\ Total phenols (mg/L) & 472.47 \(\pm\) 42.30 a & 722 \(\pm\) 172.75 b & 625.57 \(\pm\) 6.58 ab & 592.33 \(\pm\) 50.60 ab \\ Ammonium nitrogen (mg N/L) & 91.78 \(\pm\) 15.13 a & 123.50 \(\pm\) 5.07 ab & 98.02 \(\pm\) 13.29 a & 138.84 \(\pm\) 27.30 b \\ Amino nitrogen (mg N/L) & 108.24 \(\pm\) 7.92 a & 205.92 \(\pm\) 30.80 b & 119.97 \(\pm\) 17.16 a & 97.97 \(\pm\) 9.24 a \\ YAN (mg N/L) \({}^{\star}\) & 200.02 \(\pm\) 22.12 a & 329.42 \(\pm\) 35.87 b & 217.99 \(\pm\) 26.04 a & 236.81 \(\pm\) 23.80 a \\ \hline \end{tabular} \({}^{\star}\)As g/L of tartaric acid. ** YAN: yeast assimilable nitrogen. All parameters are listed with the standard deviation (n = 3). Different letters indicate significant differences between the treatments (\(\
u\)\(\leq\) 0.05).  
\end{table} 
Table 1: General parameters in musts from control and Ca, Si and Ca + Si foliar treatments. Figure 1: Terpenoids concentration (\(\mu\)g/L) in musts of control (C) and Ca, Si and Ca + Si foliar treatments. The mean volatile compound contents are shown the standard deviations SD (n = 3). Different letters indicate significant differences between foliar applications (\(p\leq 0.05\)). Of the two esters found in the musts, only the concentration of methyl salicate was influenced by foliar applications, decreasing in the Si treatment and increasing in association with Ca + Si spray application, the total content following a similar trend (Table 2). Nonetheless, esters are present in grapes in small quantities. These compounds are related to fruity aromas and, hence, play an important role in wine aroma because they are formed in high amounts during the alcoholic fermentation [44]. Figure 2: C\({}_{13}\) norisoprenoids concentration (\(\mu\)g/L) in musts from control (C) and Ca, Si and Ca + Si foliar treatments. The volatile compound concentrations are means \(\pm\) SD (n = 3). Different letters indicate significant differences between foliar applications (\(p\leq 0.05\)). Regarding alcohols, only the Ca + Si foliar treatment increased their total concentration (Table 2). The application of Ca had an inverse effect on the concentration of two alcohols, 1-heptanol and 2-ethyl-1-hexanol, the first one increasing and the latter decreasing (Table 2). The same result was observed for Si, and, moreover, after this foliar application, 1-nonanol concentration increased in the musts. These compounds are related to the green and herbaceous aromas of grapes and wines [45]. The largest family of volatiles found in the musts was carbonyl compounds, whose total content increased when Ca + Si was applied to the vines and decreased when Si was applied, with no effect associated with Ca sprays (Table 2).