## 3 Results and Discussion
### The Volatile Compounds Related to the Aroma Profiles of the Fermented Samples
On the other hand, in this order, the LC-p sample has ketone, carboxylic acid, and aldehyde groups, the LA-p sample has carboxylic acid group with a high value, then ketone, aldehyde groups, and alcohol groups, the LB-p sample has aldehyde, ketone, and carboxylic acid groups with an effect at an equal height level, followed by alcohol groups. Finally, the ST sample can be expressed with ketone, carboxylic acid, and alcohol groups at a similar height level. Additionally, the terpene group contributed to the differentiation of the profiles of the LC-p and the LH-p samples compared to the other samples, while the amount of pyrazine contributed to the differentiation of the profile of the LH-p sample. As for the compounds being examined separately, in the LA-p, LB-p, LC-p, LH-p, and ST-p samples, the most important component in the LA-p sample was hexanoic acid (\(p<0.05\)) with aroma notes of cheese, oil, pungent, and sour. Subsequent to, 2-methylbutanal, that has a natural, slight fruit-type odor, and 2-heptanone, that has a fruit and pungent-type odor were the next components; the compounds followed this order [55]. In addition, 2-nonanone that has a blue cheese, spicy, roquefort-type odor, nonyl methyl ketone that has a fresh, green, orange, and rose odor, and butanoic acid that has a cutter, cheese, and sour odor, are compounds that contributed to the aroma profile of this sample. On the other hand, ethanol, nonanal that has a fat, floral, green, and lemon-type odor, and acetone that has a pungent odor, compounds that have high values compared to other components, are among the compounds that differentiate and highlight the LA-p sample. Of these compounds, especially the hexanoic acid and 2-methylbutanal, in addition to acetone and nonanal compounds, can be associated with the _L. acidophilus_ strain in this study. Even butanoic acid, nonyl methyl ketone, 2-heptanone, and 2-nonanone supported this profile. In the LB-p sample, the most important component is hexanoic acid (\(p<0.05\)). This is followed by 2-methylbutanal, 2-heptanone, and 2-nonanone. The compounds that contribute significantly to the difference and aroma profile with their high levels in this sample and low levels in the others are 2-furanmethanol that has a burnt, caramel, and cooked-type odor, and acetaldehyde that has a floral and green apple-type odor [55]. These compounds are followed by nonyl methyl ketone and butanoic acid. Of these compounds, especially the hexanoic acid, 2-methylbutanal, 2-furanmethanol, and acetaldehyde compounds can be associated with the _L. bulgarcus_ strain in this study. The LC-p and LH-p samples form volatile aroma compound profiles similar to the LB-p sample. So, similarly, the first three compounds that stand out with their high values in these samples (with close values (\(p>0.05\))) are hexanoic acid, 2-methylbutanal, and 2-heptanone. These compounds are followed by the 2-nonanone compound with a higher value in the LC-p sample than in all samples. At the same time, acetoin, d-limonene, with citrus and mint odor, and 2-pentanone, with fruit and pungent odor, compounds [55] ensured the differentiation of the LC-p sample from the other samples and made a significant contribution to its aroma profile with the high values detected (\(p<0.05\)). In addition to these, the LH-p sample's aroma profile differed from the LC-p sample due to the effect of the significant amount of benzaldehyde with bitter almond, burnt sugar, cherry, and malt flavor (\(p<0.05\)). Of these compounds, especially the hexanoic acid, 2-methylbutanal, and 2-heptanone, in addition to the acetoin, d-limonene can be associated with the _L. casei_ strain in this study. As for the _L. heleticus_ strain, especially the hexanoic acid, 2-methylbutanal, and 2-heptanone, in addition to the benzaldehyde, can be associated with it. As the last example, in the ST-p sample, like the other four fermented products, the compound with the highest value is hexanoic acid, followed by hexanol, which is again a high value and is not present in the others.