## 3 Results
### Carbohydrates and Acids in Fermented Samples
#### 3.5.2 Characteristic VOCs of Soy, Oat and coconut
2,3-Pentanedione is considered a dairy yogurt flavor contributor [91] and was detected in high levels in fermented soy samples, in line with the findings of [PERSON] et al. [96] and [PERSON] et al. [111]. Ethyl octanoate and ethyl decanoate were detected in all fermented soy samples. [PERSON] et al. found both compounds in,cheddar cheese but only the former in soy cheese [111]. They also identified lactones in dairy cheese but not in soy cheese. In contrast, fermented soy samples in this study contained \(\delta\)-decalactone and \(\delta\)-ocalactone in different quantities. This would be a positive aspect of soy fermentation with the culture combinations used in this study for dairy alternatives. When LGG(r) was combined with YF-L02, the content of 2-heptanone, ethyl octanoate, ethyl decanoate, \(\delta\)-decalactone, 2-methyl-butan, and 2-pentyl-furan significantly decreased. When it was combined with B1-01, 2-heptanone, 2-3-pentanedione, ethyl octanoate, ethyl decanoate, 2-methyl butanal, \(\delta\)-decalactone, and \(\delta\)-ocalactone levels significantly decreased. When LGG(r) was combined with YF-L01, limonene content decreased, but 2-pentyl-furan content increased. According to [PERSON] [40] and [PERSON] et al. [101], the key volatile compounds of oat flavor are hexanal, nonanal, benzaldehyde, 3- methyl-butanal, octanal, 1-hexanol, 1-pentanol, 1-octen-3-ol, 8-methyl-1-butanol, 2-ethylfuran, 2- heptanone, 3-hydroxy-2-butanone, and 3,5-octaledien-2-one. However, only hexanal, benzaldehyde, 3-methyl-butanal, octanal, 2-ethylfuran, and 1-hexanol were found in fermented oat samples of this study. Previous literature reported variations in volatile compounds with fermentation time in oats [101]. Initial fermentation stages were associated with aldehydes and later stages with acids, alcohols, ketones, and furans. Table 14 shows VOCs in whose content LGG(r) had a significant effect. 2-3-Pentanedione was previously identified in oats [114] and it is one of the main flavor components of fermented dairy milk [19]. Its presence in fermented oat  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Category Combination** & **Actions** & **Extens** & **Temperature** & **Aldehyde** & **Lectones** & **Furan** \\ \hline
**YF-L01** & 2.4**_Pentanedione_ & **Izngly-Pentanedione** & **Izngly-Dentence** & **Izngly-Dentence** & **Izngly-Dentence** & **Izngly-Dentence** & **Izngly-Dentence** \\ \hline
**YF-L01** & 1.5 \  
samples in higher levels than in fermented soy and coconut samples may suggest oat's potential for fermented dairy alternatives. However, 2-3-Pentanedione levels decreased when the culture combination contained LGG(r). Although previous studies did not find ethyl acetate in dairy yogurt, [PERSON] et. al detected its presence in kefir [93] and it was also found in the fermented oat samples in this study. [PERSON] et al. identified nonanal, hexanal, 2-pentylfuran, 1-octen-3-ol, and 2-nonenal as lipid degradation products [101]. They observed that hexanal content decreased during fermentation of oats while 1-hexanol levels increased. This could explain the presence of the latter compound in fermented oat samples. Toluene, ethanol, acetone, and 2-propanol were the VOCs that were found in higher amounts in fermented oat. Toluene did not vary among culture combinations and, therefore, was not reported in the table, but it has been found in dairy yogurts [91] and also in fermented oat [115]. Acetone levels, previously identified by FID, drastically decreased when YF-L01 was combined with LGG(r), as well as the content of 2-propanol and ethanol. When YF-L02 was supplemented with LGG(r), 2-3-pentanedione and limonene levels decreased. The combination of BY-01 with LGG(r) increased the content of 2-methyl-3-thiolanone and ethyl acetate, but decreased the amount of 2-3-pentanedione and furufural. [PERSON] et al. and [PERSON] et al.