## 3 Results and Discussion
### Protein Analysis
#### 3.2.2 Wine Protein Composition Evaluated by SDS-PAGE  
Proteins released by yeast have been reported as exerting a positive effect on the foaming capacity of sparkling wines [11]. Soluble protein fractions of CH and XA base wines were evaluated to study their relationship with foam characteristics. For CH variety, the MW values ranged between 15.9 and 97.7 KDa, and between 18.2 and 92.2 KDa for the XA variety (Table 2). In general, SDS-PAGE did not show notable differences in the distribution and intensity of protein bands between proteins extracted with _Saccharomyces_ (Y1, Y2, Y3) and non-_Saccharomyces_ yeasts (Y4, Y5), as was observed in previous studies [23]. Figure 1: Total protein content base wines of Chardonnay (CH) and Xarel.lo (XA) elaborated with the addition of different _S. cerevisiae_ (Y1, Y2, Y3) and non-_Saccharomyces_ yeasts, _M. pulcherrina_ (Y4) and _T. delbrueckii_ (Y5). Different letters indicate significant differences between samples with different yeasts for each variety, Chardonnay (CH) and Xarel.lo (XA). Samples (n = 2). \begin{table}
\begin{tabular}{l c c c c c c c} \hline
**CH Y1 (Bands)** & V12 & V13 & V14 & V15 & V16 & V17 & \\ MW (Kda) & 96.1 & 59.4 & 28.6 & 26.1 & 22.8 & 19.4 & \\ \% & 12.8 & 2.7 & 9.1 & 7.4 & 63 & 5.1 & \\ \hline
**CH Y2 (Bands)** & V30 & V19 & V20 & V21 & V22 & V23 & \\ MW (Kda) & 97.7 & 64.3 & 27.2 & 24.9 & 22.1 & 18.6 & \\ \% & 10.1 & 2.7 & 11.6 & 25.2 & 48.4 & 2 & \\ \hline
**CH Y3 (Bands)** & V19 & V20 & V21 & V22 & V23 & V24 & V25 & V26 \\ MW (Kda) & 66.7 & 57.4 & 47.2 & 40.4 & 32.7 & 26.4 & 21 & 18 \\ \% & 14.6 & 12.8 & 5.7 & 5.7 & 7.2 & 7.2 & 32.2 & 2.2 \\ \hline
**CH Y4 (Bands)** & V11 & V12 & V13 & V14 & V15 & V16 & V17 & V18 \\ MW (Kda) & 74.8 & 53.9 & 36.3 & 28.2 & 23.4 & 20.2 & 18.7 & 15.9 \\ \% & 28.8 & 4.5 & 2.4 & 12.2 & 42.9 & 3.7 & 4.3 & 1.2 \\ \hline
**CH Y5 (Bands)** & V1 & V2 & V3 & V4 & V5 & V6 & V7 & V8 \\ MW (Kda) & 68.5 & 48.7 & 35.9 & 26.8 & 23.1 & 20.3 & 18 & 16.2 \\ \% & 20.2 & 2.9 & 5.7 & 25.1 & 30 & 3.7 & 3.2 & 9.3 \\ \hline
**XA Y1 (Bands)** & V29 & V30 & V31 & V32 & & & & \\ MW (Kda) & 68.4 & 26.9 & 21.4 & 18.2 & & & \\ \% & 27.6 & 33.9 & 26.5 & 12.1 & & & \\ \hline
**XA Y2 (Bands)** & V22 & V23 & V24 & V25 & & & \\ MW (Kda) & 73.2 & 29.5 & 27.6 & 25.5 & & & \\ \% & 43.9 & 26.8 & 19.5 & 9.8 & & & \\ \hline
**XA Y3 (Bands)** & V11 & V12 & V13 & V14 & V15 & & \\ MW (Kda) & 92.1 & 32.9 & 28.9 & 25.3 & 22.9 & & \\ \% & 10.5 & 14.4 & 3.2 & 70.4 & 1.5 & & \\ \hline
**XA Y4 (Bands)** & V1 & V2 & V3 & V4 & V5 & & \\ MW (Kda) & 91.6 & 31.7 & 29.5 & 27.6 & 23.9 & & \\ \% & 24.9 & 3.3 & 38.2 & 15.4 & 18.3 & & \\ \hline
**XA Y5 (Bands)** & V25 & V26 & V27 & V28 & V29 & & \\ MW (Kda) & 92.2 & 31.5 & 28.7 & 25 & 20.8 & & \\ \% & 28.1 & 50.2 & 11.3 & 6.1 & 4.3 & & \\ \hline \multicolumn{2}{c|}{\(10\%<\)} & & & & & \(<80\%\) \\ \hline \end{tabular}
\end{table} 
Table 2: Analysis of the protein profile by SDS-PAGE and quantification in terms of the percentage of protein bands fractions (%) by detecting their molecular weights (MW), of the base wine of Chardonnay (CH) and Xarel.lo (XA) elaborated with different yeast strains: _Saccharomyces cerevisiae_ (Y1, Y2, Y3) and non-Saccharomyces, _M. pulcherrina_ (Y4) and _T. delbrueckii_ (Y5). As shown in Table 2, Chardonnay samples showed the most intense bands around molecular weights between 21 and 24 KDa. When observing the yeast effect, CH base wines fermented with the addition of Y1 presented up to 63% of their total content with an MW of 22.8 KDa. A similar trend was observed in wines with the addition of Y2, which showed 48.4% protein of 22.1 KDa and 25% of 24.9 KDa of MW. The wine with the addition of Y3 showed differences with respect to the previous wines, because although it presented 30% protein with MW of 21 KDa, this sample also presented around 30% of the proteins with higher molecular weights of 66.7 and 57.4 KDa.