## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **All Features** & **RFE** & **Correlation** & **LASSO** & **ANOVA** & **PCA** \\ \hline Neural Network & 1.77 & 12.88 & **0.69** & 2.83 & 2.63 & 1.63 \\ \hline Random Forest & 4.45 & 9.22 & 11.01 & 7.35 & **3.45** & 4.15 \\ \hline Support Vector & 29.12 & 29.52 & **28.24** & 30.76 & 30.04 & 28.64 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: MSE values for predictions for day 4 of MEL production. Five predictions were attained for each model by using each of the five feature subsets used as input for model training. Lower MSE results achieved by each model are represented in bold. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Experimental** & **RF Predictions (g/L)** & **NN Predictions (g/L)** & **SVM Predictions (g/L)** \\
**Values (g/L)** & **\(\pm\) Error** & **\(\pm\) Error** & **\(\pm\) Error** \\ \hline
0.08 & 0.14 & 0.00 & 1.41 \\  & \(\pm\) 0.06 & \(\pm\) 0.08 & \(\pm\) 1.33 \\
4.17 & 7.19 & 4.59 & 1.54 \\  & \(\pm\) 3.02 & \(\pm\) 0.42 & \(\pm\) 2.63 \\
3.60 & 5.24 & 3.11 & 1.67 \\  & \(\pm\) 1.64 & \(\pm\) 0.49 & \(\pm\) 1.93 \\
13.08 & 10.16 & 10.81 & 1.91 \\  & \(\pm\) 2.92 & \(\pm\) 2.27 & \(\pm\) 11.17 \\
9.76 & 9.92 & 10.00 & 1.58 \\  & \(\pm\) 0.16 & \(\pm\) 0.24 & \(\pm\) 8.18 \\
1.17 & 3.32 & 1.42 & 1.24 \\  & \(\pm\) 2.15 & \(\pm\) 0.25 & \(\pm\) 0.07 \\
0.12 & 2.00 & 0.59 & 1.50 \\  & \(\pm\) 1.88 & \(\pm\) 0.47 & \(\pm\) 1.38 \\
0.38 & 0.50 & 1.20 & 1.61 \\  & \(\pm\) 0.12 & \(\pm\) 0.82 & \(\pm\) 1.23 \\
6.99 & 4.62 & 6.56 & 1.76 \\  & \(\pm\) 2.37 & \(\pm\) 0.43 & \(\pm\) 5.23 \\
8.82 & 8.32 & 8.52 & 1.91 \\  & \(\pm\) 0.50 & \(\pm\) 0.30 & \(\pm\) 6.91 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of experimental values for MEL production on the fourth day of fermentation with RF, NN, and SVM predictions. The prediction errors represent the absolute error between the predictions and actual values and are on the line below the predictions. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **All Features** & **RFE** & **Correlation** & **LASSO** & **ANOVA** & **PCA** \\ \hline Neural Network & 7.01 & 3.76 & 6.47 & 10.31 & **1.63** & 4.2 \\ \hline Random Forest & 12.99 & 13.82 & 27.07 & **9.48** & 59.39 & 27.96 \\ \hline Support Vector & 44.21 & 37.36 & 41.34 & 45.01 & 36.63 & **36.25** \\ \hline \hline \end{tabular}
\end{table} 
Table 4: MSE values for predictions for day 7 of MEL production. Five predictions were attained for each model by using each of the five feature subsets used as input for model training. Lower MSE results achieved by each model are represented in bold. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Experimental** & **RF Predictions (g/L)** & **NN Predictions (g/L)** & **SVM Predictions (g/L)** \\
**Values (g/L)** & **\(\pm\) Error** & **\(\pm\) Error** & **\(\pm\) Error** \\ \hline
15.45 & 10.16 & 15.64 & 6.73 \\  & \(\pm\) 5.29 & \(\pm\) 0.19 & \(\pm\) 8.72 \\
1.97 & 4.23 & 3.62 & 5.84 \\  & \(\pm\) 2.26 & \(\pm\) 1.65 & \(\pm\) 3.87 \\
3.65 & 4.23 & 4.77 & 5.73 \\  & \(\pm\) 0.58 & \(\pm\) 1.12 & \(\pm\) 2.08 \\
4.34 & 4.74 & 6.71 & 6.58 \\  & \(\pm\) 0.40 & \(\pm\) 2.37 & \(\pm\) 2.24 \\
10.32 & 13.83 & 11.79 & 7.06 \\  & \(\pm\) 3.51 & \(\pm\) 1.47 & \(\pm\) 3.26 \\
7.77 & 5.62 & 9.24 & 7.74 \\  & \(\pm\) 2.15 & \(\pm\) 1.47 & \(\pm\) 0.03 \\
11.42 & 5.62 & 10.74 & 6.74 \\  & \(\pm\) 5.80 & \(\pm\) 0.68 & \(\pm\) 4.68 \\
20.99 & 18397 & 20.75 & 7.74 \\  & \(\pm\) 2.02 & \(\pm\) 0.24 & \(\pm\) 13.25 \\
7.77 & 5.62 & 8.67 & 6.89 \\  & \(\pm\) 2.15 & \(\pm\) 0.90 & \(\pm\) 0.88 \\
13.94 & 13.01 & 14.93 & 6.72 \\  & \(\pm\) 0.93 & \(\pm\) 0.99 & \(\pm\) 7.22 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Comparison of experimental values for MEL production on the seventh day of fermentation with RF, NN, and SVM predictions. The prediction errors represent the absolute error between the predictions and actual values and are on the line below the predictions. Figure 2: Concentration of MELs on day 4 (in red) and day 7 (in blue) of the fermentation process.