# Flavor and Functional Analysis of _Lactobacillus plantarum_
## 3 Results and Discussion
### Correlations between Chemical Characteristics and Aroma Components  
The aromatic compounds may interact with each other affecting the final aroma of fermented food [53]. Correlation analyses can reveal the relationships between aromatic compounds and their chemical attributes [51]. The calculated Pearson correlation coefficients are shown in Figure 4 and Figure S8. TA (r = 0.74), lactic acid (r = 0.90), quinic acid (r = 0.95) and citric acid (r = 0.98) positively correlated with bacterial viable count, while lactic acid (r = \(-\)0.76), quinic acid (r = \(-\)0.85) and citric acid (r = \(-\)0.96) negatively correlated with \(\alpha\)-ionone. Some aromatic compounds were related to organic acids. Some other positive correlations were \(\alpha\)-pinene (r = 0.98), 2-undecanone (r = 0.88) and \(\beta\)-ionone (r = 0.91) with lactic acid, malic acid with limonene (r = 0.97) and \(\beta\)-pinene (r = 0.90), and citric acid with \(\alpha\)-pinene (r = 0.74) and eugenol (r = 0.85).  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Vuclide** & \multirow{2}{*}{**RI**} & \multicolumn{6}{c}{**Concentations (Mg/I.3)**} & \multicolumn{1}{c}{**Threshold in**} & \multicolumn{1}{c}{**Flavor**} \\
**Compounds** & & \multicolumn{1}{c}{**St0**} & \multicolumn{1}{c}{**St2**} & \multicolumn{1}{c}{**St4**} & \multicolumn{1}{c}{**St6**} & \multicolumn{1}{c}{**St8**} & \multicolumn{1}{c}{**St9**} & \multicolumn{1}{c}{**St12**} & \multicolumn{1}{c}{**Waer (ug/I.3)**} & \multicolumn{1}{c}{**Description**} \\ \hline \(\beta\)-Freene & 1112 & 170.41 \(\pm\) 1.111 & 27.53 \(\pm\) 0.904 & 23.81 \(\pm\) 0.27 & 51.00 \(\pm\) 3.38 & 44.021 \(\pm\) 2.29* & 123.25 \(\pm\) 8.05* & 110.45 \(\pm\) 4.51* & 0.0022 & Grassy, Robin \\ \(\beta\)-MyGreene & 1161 & 175.52 \(\pm\) 12.94 & 120.29 \(\pm\) 4.91 & 47.21 \(\pm\) 0.57* & 20.53 \(\pm\) 1.67* & 10.48 \(\pm\) 0.34* & 6.89 \(\pm\) 0.56* & 3.53 \(\pm\) 0.07* & 0.0012 & Multi-like \\ D-Limemore & 1167 & 342.3 \(\pm\) 0.84* & 36.99 \(\pm\) 0.004 & 77.25 \(\pm\) 18.9* & 82.40 \(\pm\) 0.67* & 98.29 \(\pm\) 4.01* & 100.08 \(\pm\) 0.82* & 110.65 \(\pm\) 5.42* & 0.034 & Citrus-like \\ \(\beta\)-Freene & 1028 & & & & & & & & \\ \(\beta\)-Amyltraum & 1231 & 16.43 \(\pm\) 0.54* & 13.37 \(\pm\) 0.90* & 17.28 \(\pm\) 0.85* & - & - & - & 0.0058 & Bon, fruit \\ Dequal & 1498 & & & & & & & & \\ \(\beta\)-Lome & 1627 & 2.65 \(\pm\) 0.13* & 2.72 \(\pm\) 0.13* & 3.02 \(\pm\) 0.21* & - & - & - & 0.005 & Violet \\ Linaulod & 1547 & 1716.45 \(\pm\) 1.04* & 1332.10 \(\pm\) 54.8* & 124.84 \(\pm\) 8.89* & 108.85 \(\pm\) 8.74* & 106.022 \(\pm\) 8.91* & 109.47 \(\pm\) 10.08* & 128.04 \(\pm\) 10.30* & 0.025 & Florid, several \\ \(\beta\)-Limemore & 1598 & & & & & & & & \\ \(\beta\)-Lome & 2308 & 10.74 \(\pm\) 0.35* & 8.84 \(\pm\) 2.9* & 5.84 \(\pm\) 0.33* & 6.93 \(\pm\) 0.45* & 6.68 \(\pm\) 2.09* & 24.85 \(\pm\) 0.43* & 6.23 \(\pm\) 0.16* & 0.0009 & Velocs, roe \\ \(\gamma\)-Deconolactone & 2138 & 145.47 \(\pm\) 0.47* & 8.57 \(\pm\) 0.73* & 5.10 \(\pm\) 0.21* & 6.74 \(\pm\) 0.04* & 7.78 \(\pm\) 0.54* & 6.95 \(\pm\) 0.29* & 24.11 \(\pm\) 0.60* & 0.0011 & Prouch, strawberry \\ \(\gamma\)-Exponolactone & 2169 & - & & 2.37 \(\pm\) 0.04* & 3.37 \(\pm\) 0.16* & 4.90 \(\pm\) 0.04* & 7.77 \(\pm\) 0.40* & 10.30 \(\pm\) 0.42* & 6.94 \(\pm\) 0.51* & 0.006 & Clove \\ \hline \end{tabular}
\end{table}
Table 1: OAVs and flavor descriptions of selected main volatile compounds in seven fermentation stages of apriot juice.  
Some alcohols and esters are produced from acids. For example, the formation of ethyl lactate and ethyl acetate is related to the content of lactic and acetic acids [59]. Likewise, linalool is synthesized through a series of reactions during fermentation [60]. The correlation analysis showed that the aromatic odors were affected by the substrate and other odors in a complex manner [61]. The fermentation process can be improved, such as mixed fermentation, with a clear understanding of flavors [54], which demands more in-depth studies.