# Aromatic Potential of Diverse Non-Conventional Yeast Species for Winemaking and Brewing
## 3 Results and Discussion
### Microwine
#### 3.1.2 Aroma Profiles
\begin{table}
\begin{tabular}{c c c c c} \hline
**Strain 1** & **Strain 2** & **Ratio** & **Sugars (g/L)** & **Ethanol\% (v/v)** \\ \hline WS34/70 & & & nd \({}^{\mathrm{d}}\) & \(5.9\pm 0.6\,^{\mathrm{a}}\) \\ CBS 772.71 & WS34/70 & 5:1 & nd \({}^{\mathrm{d}}\) & \(5.6\pm 1.4\,^{\mathrm{a}}\) \\ CBS 772.71 & WS34/70 & 20:1 & nd \({}^{\mathrm{d}}\) & \(6.5\pm 0.4\,^{\mathrm{a}}\) \\ CBS 2567 & WS34/70 & 5:1 & \(5.4\pm 1.4\,^{\mathrm{a-c}}\) & \(6.2\pm 1.1\,^{\mathrm{a}}\) \\ CBS 2567 & WS34/70 & 20:1 & \(2.4\pm 0.7\,^{\mathrm{c}d}\) & \(6.0\pm 1.4\,^{\mathrm{a}}\) \\ CBS 5552 & WS34/70 & 5:1 & nd \({}^{\mathrm{d}}\) & \(6.4\pm 0.3\,^{\mathrm{a}}\) \\ CBS 5552 & WS34/70 & 20:1 & nd \({}^{\mathrm{d}}\) & \(5.4\pm 1.3\,^{\mathrm{a}}\) \\ CBS 6641 & WS34/70 & 5:1 & \(2.2\pm 0.4\,^{\mathrm{c}d}\) & \(6.0\pm 0.6\,^{\mathrm{a}}\) \\ CBS 6641 & WS34/70 & 20:1 & \(5.2\pm 1.0\,^{\mathrm{a-c}}\) & \(6.4\pm 0.5\,^{\mathrm{a}}\) \\ CBS 7692 & WS34/70 & 5:1 & \(0.9\pm 1.2\,^{\mathrm{d}}\) & \(6.8\pm 0.3\,^{\mathrm{a}}\) \\ CBS 7692 & WS34/70 & 20:1 & \(3.5\pm 1.9\,^{\mathrm{b-d}}\) & \(6.2\pm 1.4\,^{\mathrm{a}}\) \\ CBS 8031 & WS34/70 & 5:1 & nd \({}^{\mathrm{d}}\) & \(6.9\pm 1.2\,^{\mathrm{a}}\) \\ CBS 8031 & WS34/70 & 20:1 & \(1.0\pm 1.4\,^{\mathrm{d}}\) & \(6.2\pm 0.6\,^{\mathrm{a}}\) \\ CBS 8849 & WS34/70 & 5:1 & \(7.1\pm 0.6\,^{\mathrm{a,b}}\) & \(5.5\pm 1.2\,^{\mathrm{a}}\) \\ CBS 8849 & WS34/70 & 20:1 & nd \({}^{\mathrm{d}}\) & \(6.5\pm 0.6\,^{\mathrm{a}}\) \\ CBS 8860 & WS34/70 & 5:1 & nd \({}^{\mathrm{d}}\) & \(6.0\pm 0.4\,^{\mathrm{a}}\) \\ CBS 8860 & WS34/70 & 20:1 & \(0.8\pm 1.1\,^{\mathrm{d}}\) & \(6.8\pm 0.1\,^{\mathrm{a}}\) \\ CBS 9716 & WS34/70 & 5:1 & \(7.7\pm 0.4\,^{\mathrm{a}}\) & \(5.7\pm 1.1\,^{\mathrm{a}}\) \\ CBS 9716 & WS34/70 & 20:1 & \(3.9\pm 1.6\,^{\mathrm{a-d}}\) & \(6.6\pm 0.3\,^{\mathrm{a}}\) \\ CBS 10400 & WS34/70 & 5:1 & nd \({}^{\mathrm{d}}\) & \(7.3\pm 0.4\,^{\mathrm{a}}\) \\ CBS 10400 & WS34/70 & 20:1 & \(1.6\pm 0.5\,^{\mathrm{c}d}\) & \(6.6\pm 0.4\,^{\mathrm{a}}\) \\ \hline \end{tabular}  
Letters indicate grouping according to ANOVA.  
\end{table} 
Table 5: Residual sugars and ethanol in the resulting microbeers. It is worth mentioning the high isoamyl acetate production by pure cultures of _S. caribaea_ CBS 7692 and _K. gamospora_ CBS 10400, which probably resultsin a strong banana flavour, as already observed in bread fermented by the latter [16]. These strains also present high synthesis of phenylethyl acetate, which was already seen by [PERSON] et al. [3] in sequential pilot scale fermentations. The strains _G. geotrichum_ CBS 772.72, _Hanseniagpora vienea_ CBS 8031 and _Z. kombuchaensis_ CBS 8849 also showed high production of phenylethyl acetate (Table 4), which probably resulted in a remarkable rose aroma. [PERSON] et al. [18] described high production of this ester in _H. vineae_ and _H. guilliernondii_, which was in accordance with our results, especially in case of the former (see CBS 8031 in Table 4). Ethyl esters, as acetate esters, are desirable aroma compounds presenting fruity and flowery flavours. Some of the most important ethyl esters in alcoholic beverages are ethyl caproate (green apple, aniseed aroma; sensory threshold: 0.05 mg/L), ethyl caprylate (sour apple, sweet soap aroma; sensory threshold: 0.02 mg/L) and ethyl caprate (apple, floral, soap aroma; sensory threshold: 0.20 mg/L) [13]. Multifactorial ANOVA shows that the type of culture carrying out the fermentation, pure or mixed, significantly influenced ethyl caproate and ethyl caprylate yield, being the latter also affected by the non-_Saccharomyces_ strain. On the contrary, none of the factors were significantly important to determine ethyl caprate levels, which even appeared below its sensory threshold in some pure cultures.