## 3 Results and Discussion
### Volatile Compound Analyses
#### 3.3.1 Higher Alcohols  
The analysis of volatile alcohols in samples that were fermented with the strains Zb-A19Y5, Tc-A9Y1, and Zb-K29Y2 reveals intriguing insights into the distinct chemical signatures of each sample (Table 3). In general, interspecies differences among _Z. bailii_ strains are noticed regarding the production of higher alcohols. In more detail, isoamyl alcohol demonstrates a significant difference, with sample Zb-K29Y2 exhibiting the highest concentration at 604.33 \(\pm\) 76.80 mg/L. This discrepancy suggests that variations in isoamyl alcohol levels may contribute to the distinction in the flavor profiles of these wines. Isoamyl alcohol is generally described by banana- and fused-type odors. A previous study demonstrates an amplification of butyric notes with the addition of isoamyl alcohol (3-methylbutan-1-ol) in a fruity model solution [58]. The literature provides evidence that higher alcohols are found in total concentrations ranging from 0.2 to 1.2 g/L in white  
\begin{table}
\begin{tabular}{c c c c c} \hline  & **Must** & **Zb-A19Y5** & **Tc-A9Y1** & **Zb-K29Y2** \\ \hline Total sugars (g/L) & 230 \(\pm\) 0.03 & 3.85 \(\pm\) 1.16 c & 1.00 \(\pm\) 0.00 a & 3.65 \(\pm\) 1.32 b \\ Ethanol (\%vol) & & 13.41 \(\pm\) 0.07 c & 11.79 \(\pm\) 0.04 a & 13.11 \(\pm\) 0.05 b \\ Ethanol Yield (Y\({}_{\text{EOH/TS}}\), g/g) & & 0.45 & 0.39 & 0.44 \\ pH & 3.20 \(\pm\) 0.03 & 3.15 \(\pm\) 0.01 a & 3.19 \(\pm\) 0.01 b & 3.12 \(\pm\) 0.01 c \\ Total acidity (g tartaric acid/L) & 5.77 \(\pm\) 0.06 & 4.35 \(\pm\) 0.08 a & 4.33 \(\pm\) 0.03 a & 3.92 \(\pm\) 0.02 b \\ Volatile acidity (g acetic acid/L) & & 0.42 \(\pm\) 0.03 a & 0.47 \(\pm\) 0.01 b & 0.41 \(\pm\) 0.02 a \\ YAN (mg N2/L) & 609.00 \(\pm\) 4.76 & 105.70 \(\pm\) 3.01 a & 100.10 \(\pm\) 4.83 a & 99.40 \(\pm\) 0.74 a \\ Total SO2 (mg/L) & 16.60 \(\pm\) 0.01 & 14.10 \(\pm\) 1.82 a & 16.00 \(\pm\) 1.51 a & 14.10 \(\pm\) 1.80 a \\ Free SO2 (mg/L) & 5.10 \(\pm\) 0.10 & 6.40 \(\pm\) 0.05 a & 5.80 \(\pm\) 0.09 a & 5.80 \(\pm\) 0.07 a \\ _L_-malic acid (g/L) & n.d. & n.d. & n.d. & n.d. \\ \hline \end{tabular} n.d.: not detected.  
\end{table}
Table 2: Mean concentration of enological parameters of Assyrtiko must and wines produced using three different non-_Saccharomyces_ strains (Zb-A19Y5, Tc-A9Y1, and Zb-K29Y2). Different letters in each row indicate the significance of One-way Analysis of Variance (ANOVA), which was followed by [PERSON]’s post hoc test (_p_ \(<\) 0.05).  
wines [59]. While 2-phenylethan-1-ol imparts a rose-like aroma, other higher alcohols are often associated with fused oil, solvent, or malt scents [60]. Research indicates that higher alcohols may enhance the aromatic complexity of wine or, in some instances, mask certain flavors, contingent upon their concentrations [61]. When present below 300 mg/L, higher alcohols are generally considered contributors to a desirable complexity of wine; however, concentrations exceeding 400 mg/L are deemed to have a negative impact on wine's quality [61]. Phenylethyl alcohol, linked with floral notes, exhibits a pronounced concentration in the samples, ranging from 246.63 \(\pm\) 15.09 mg/L to 319.92 \(\pm\) 36.05 mg/L.  
Intriguingly, tryptophan, a secondary metabolite, also reveals noteworthy differences among the samples. Wines that were fermented with Zb-A19Y5 and Tc-A9Y1 strains were registered as having a concentration of 21.21 \(\pm\) 0.81 mg/L and 20.62 \(\pm\) 0.80 mg/L, respectively, whereas wines that were inoculated with Zb-K29Y1 differed significantly, with 8.76 \(\pm\) 0.74 mg/L. This divergence underscores the role of tryptophan, which is a compound that is strongly impacted by yeast metabolism. According to previous research, aromatic alcohols such as phenylethanol contribute positively to the organoleptic characteristics of wines [62]. According to previous research, _Z. buili_ was found in Maotai-flavor liquor fermentation and enhanced the production of higher alcohols, which greatly impact the unique aroma [63].