# Impact of Selected Yeast Strains on Quality Parameters of Obtained Sauerkraut
## 3 Results and Discussion
### Volatile Compounds
\begin{table}
\begin{tabular}{l c c c c c c c c c c c c c c c c} \hline \hline  & & & & & & & & & & & & & & & & & & & & & \\ (mg/kg) & & & & & & & & & & & & & & & & & & & & & \\ \hline \multicolumn{11}{c}{**Eaters**} \\ \hline Ethyl acetate & 614 & 43 & 143.a & 610.ab & 440.ab & 150.bc & 640.ab & 331.a & 1008.a-c & 226.a & 208.a & 162.a & 1795.c & 129 & * & 5 \\ \hline
2-Butoxyethyl acetate & 1061 & 43 & 1.13 & 1.52 & 3.86 & 1.10 & 5.34 & 1.85 & 3.50 & 5.90 & 3.13 & 2.68 & 0.71 & 0.42 & ns & 0.1 \\ \hline Ethyl octanoate & 1204 & 88 & 02.3 ab & 2.25 e & 0.92 d & 7.59 & 0.51 c & 014.a & 0.97 d & 0.23 ab & 0.49 bc & 0.19 a & 1.10 & 0.38 & *** & 0.07 \\ \hline Ethyl 2-methyloctanoate & 1225 & 102 & 120.0 & 84.5 c & 928.e & 456.b & 22.0 a & 124.a & 121.a & 129.a & 117.a & 13.4 a & 17.0 a & 5.4 & *** & na \\ \hline Phenethyl acetate & 1245 & 104 & 0.19 b-d & 0.97 f & 0.47 e & 0.27 cd & 0.17 bc & 0.00 a & 0.29 d & 0.00 a & 0.27 cd & 0.11 ab & 0.96 & 0.06 & *** & 0.02 \\ \hline Propyl nonanoate & 1377 & 61 & 0.1 a & 6.0 c & 3.5 b & 6.3 c & 1.7 ab & 0.2 a & 0.7 a & 0.1 a & 0.1 a & 0.1 a & 0.0 a & 0.5 & *** & na \\ \hline Ethyl decanoate & 1391 & 88 & 2.9 a-e & 26.0 f & 8.3 a-d & 16.6 e & 6.0 a-e & 14.4 a & 9.7 b-e & 8.6 b-e & 10.6 a & 1.98 b & 150.6 a & 1.43 & *** & 6.3 \\ \hline Ethyl octanoate & 1596 & 88 & 12.4 & 6.0 a-e & 132.c & 69 a-b & 53.b & 92 a & 7.5 ab & 93.6 b & 62.0 a & 41.1 & 22.4 b & 12 & **na** & 12 & **na** \\ \hline Ethyl dodecanoate & 1596 & 88 & 12.4 & 6.0 a-e & 42.ab & 17.0 bc & 21.2 d & 3.5 ab & 18.4 cd & 6.3 a-h & 110.0 & 22.2 a & 39.9 b & 1.3 & *** & 0.4 \\ \hline \multicolumn{11}{c}{} \\ 1-Methylethyl & 1627 & 60 & 3.5 ab & 8.4 d & 4.9 bc & 7.1d & 22.2 ab & 1.4 a & 2.9 ab & 2.9 ab & 2.3 ab & 1.2 a & 68.6 cd & 0.5 & *** & na \\ \hline Benzyl benzoate & 1749 & 105 & 24.0 b & 45.9 c & 22.3 b & 38.3 c & 169.ab & 90.3 & 19.8 ab & 23.9 b & 18.2 ab & 101.4 & 58.3 & 2.8 & 0.341 \\ \hline Ethyl tetradaconate & 1787 & 88 & 02.1 a & 16.0 a & 3.4 b & 4.6 b & 0.8 a & 3.00 a & 4.57 b & 7.76 b & 12.4 b & 2.73 b & 0.4 & *** & 4 \\ \hline Ethyl hexadecanoate & 1979 & 88 & 1.7 a & 1.6 a & 1.0 a & 1.9 a & 1.4 a & 11.a & 4.1 c & 5.4 c & 3.9 b & 2.4 a & 27.0 a & 0.4 & *** & 2 \\ \hlineGlucosinolates present in plants of the genus _Brassica_, are products of secondary metabolism. During fermentation, the substance can undergo hydrolysis, leading to the creation of volatile compounds like isothicyanates, thiocyanates, nitriles and epithionitriles [35]. _Brassica_ vegetables owe their 'cabbage' flavour to the presence of sulphides, disulphides, trisulphides, tetrasulphides, and other compounds formed via the hydrolysis of isothicyanates, which can occur during heat treatment [36]. Our research revealed the presence of eight compounds from this group (Table 5). Most of them were present at levels above the threshold and thus significantly influenced the aroma of the sauerkraut obtained. In total, the highest number of these compounds was produced in samples with yeasts of all species except _D. hansenii_. This was mainly due to the low levels of carbon disulphide, methyl thiocyanate and dimethyl disulphide in these samples. Previous research suggests that halophilic bacterial species are the most likely microorganisms to use thiocyanates and related compounds as a source of sulphur, carbon and nitrogen [37]. Therefore, the formation of higher levels of these compounds may be due to increased competition for nutrients when large numbers of yeast cells are introduced into the mixture. This can also lead to a reduction in the amount of glucosinolates in the product, which may be undesirable due to their health-promoting properties [38]. Another undesirable consequence of increased levels of thiocyanate derivatives may be a change in flavour, with intense sulphuric, pungent, green and mustardy notes characterising these components [39]. Terpenes are a group of compounds that occur naturally in plants, mostly in a bound form. During fermentation, they are released or microbiologically biotransformed into others.