## 4 Conclusions  
The results of this study indicated that UFAs type and content in grape must significantly influence cell growth, the fermentation process, and the productions of yeast-derived volatile compounds. Initial adding low concentrations of UFAs (12 and 60 mg/L), especially LA and OA, promoted cell growth, fermentation activity, and most volatiles when compared to the control. However, this effect disappeared and conversely became the inhibition with the increment of UFAs concentrations (120 and 240 mg/L). Regarding the individual aromatic effects of different UFAs, low concentration of OA and LA (12 and 60 mg/L) enhanced the productions of MCFAs (octanoic acid and decanoic acid) and acetate esters (isoamyl acetate), in which OA had a pronounced effect on acetate esters biosynthesis, while LA facilitated more MCFAs formation. In comparison, ALA with low concentration had no effect on acetate esters production. Conversely, the supplementation of 120 and 240 mg/L ALA greatly promoted the productions of C6 alcohols (1-hexanol) and higher alcohols (isobutyl alcohol and 2,3-butanediol). The additions of UFAs were unfavorable for the biosynthesis of ethyl esters, with the exception of ethyl hexanoate in 12 mg/L OA added fermentation. As a result, different aromatic profiles of wines were produced by the variation of UFAs types and levels showed by PCA. The enological characteristics of ALA wines were distinct with OA and LA wines. UFAs levels had a stronger contribution to the variance of the aromatic compounds than UFAs type in OA and LA wines. The transcriptional data revealed that the expressions of aroma-related genes, such as _BAT1_, _BAT2_, _PDC1_, _PDC5_, _PDC6_, _ACC1_, _FAS1_, _ATF1_, _EEB1_, and _EHT1_ were correlated with aroma compounds production in different fermentations. Our results collectively suggested that different UFAs have no similar enological effects during red wine fermentation. Thus, besides concentration, it is essential to consider the types of UFAs in grape must when applying the strategy of adjusting UFAs contents to modulate the aromatic quality of wine products, which might be a potential way to increase the aromatic diversity and quality of wine products. For example, to obtain a wine with high fruity or floral characters, the regulation of grape must to contain low content of OA or LA could be taken into consideration. On the other hand, if a wine is required to have relative high alcohols for further storage, a grape must with high ALA could be a good choice. Future work will be done to further confirm the individual aromatic effect of different UFAs in other grape varieties, such as Melort and Sauvignon Blanc being fermented by different _S. cerevisiae_ strains. **Supplementary Materials:** The following are available online. Figure S1: Fermentation profiles of different treatments. Progress of biomass and sugar concentration throughout the fermentation. Biomass is reported as dry cell weight (DCW). Data points represent the mean values from triplicate fermentations and the vertical bars show \(\pm\) SD. Figure S2: Effect of different treatments on the composition of fatty acids (SFAs, saturated fatty acids; UFAs, unsaturated fatty acids) in yeast cells. Values of the same compound marked with the same lowercase letters indicates no significant difference (\(p<0.05\), Duncan's test). Table S1: Effect of UFAs on the concentration (ug/L) of volatile compounds in wines with different treatments. Table S2: Description of genes detected in this work. Table S3: Calibration curves for quantification of glycerol, ethanol, citric acid, malic acid, succinic acid, lactic acid and acetic acid in this study. Table S4: Quantitative ion, quantitative standards and calibration curves for quantification of fatty acids in this study. Table S5: Quantitative ion, quantitative standards and calibration curves for quantification of volatile compounds in this study. Table S6: Time of sampling of the alcoholic fermentation for Real-time PCR.