## 3 Results and Discussion
### Process Design and Economic Analysis
The results for samples after adhesion were not included in the economic assessment of the project, since only the non-adherent cells present in the suspension after incubation could be measured using flow cytometry. Based on the results it can be concluded that the number of viable cells after drying is not a good indicator of the product quality. For better assessment, the number of cells surviving the technological process, storage, and digestion should be most important for the consumer. Economic evaluation based on the price of achieving preparation containing 1 kg of cells that meet those requirements should also be considered by the producer while planning the process. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Unit** & \\ \hline DFC & \$ & 1,584,000 \\ TPDC & \$ & 861,000 \\ TPIC & \$ & 516,000 \\ CFC & \$ & 207,000 \\ Operating cost & \$ & 100,000 \\ Batch size & kg & 326,91 \\ Cost basis annual & kg/year & 34,979 \\ Gross margin & \% & 71.98 \\ Return on investment (ROI) & \% & 11.51 \\ Payback time (PBT) & year & 4.33 \\ Net present value (NPV at 7\%) & \$ & 909,000 \\ \hline Revenues (per year) & \$ & 350,000 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Economic evaluation summary. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Equipment** & **Size** & **Purchase cost (PC) (\$)** \\ \hline Fluid bed dryer & 415.97 L & 107,000 \\ Bioreactor & 296.11 L & 150,000 \\ Seed bioreactor & 18.34 L & 29,950 \\ Heat sterilizer & 66.17 L/h rated & 30,000 \\ Blending tank & 308.29 L & 11,400 \\ Shake flask rack & 2 L & 1000 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Equipment and its purchase cost summary. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Unit** & **Production Cost** & **Production Cost** \\
**Variant** & **Production** & **(\$/1 kg VB Cells** & **(\$/1 kg VB Cells** \\  & **Cost (\$/kg)** & **Pre-Digestion)** & **after Digestion)** \\ \hline Dried \({}^{\text{A}}\) & 2.59 & 30.58 \({}^{\text{cde}}\)\(\pm\) 1.05 & 173.83 \({}^{\text{a}}\)\(\pm\) 32.59 \\ Dried, 12 months \({}^{\text{B}}\) & 2.59 & 28.09 \({}^{\text{cde}}\)\(\pm\) 2.45 & 22.19 \({}^{\text{cde}}\)\(\pm\) 2.11 \\ Dried heat shock \({}^{\text{A}}\) & 2.59 & 29.40 \({}^{\text{cde}}\)\(\pm\) 0.13 & 134.20 \({}^{\text{b}}\)\(\pm\) 12.05 \\ Dried heat shock 12 months \({}^{\text{B}}\) & 2.59 & 10.52 \({}^{\text{e}}\)\(\pm\) 0.36 & 27.91 \({}^{\text{cde}}\)\(\pm\) 0.98 \\ Dried pH shock \({}^{\text{A}}\) & 2.63 & 29.35 \({}^{\text{cde}}\)\(\pm\) 1.99 & 144.51 \({}^{\text{b}}\)\(\pm\) 10.82 \\ Dried pH shock 12 months \({}^{\text{B}}\) & 2.63 & 10.58 \({}^{\text{e}}\)\(\pm\) 0.37 & 35.11 \({}^{\text{cde}}\)\(\pm\) 2.87 \\ Coated \({}^{\text{A}}\) & 3.01 & 30.31 \({}^{\text{cde}}\)\(\pm\) 1.73 & 38.18 \({}^{\text{c}}\)\(\pm\) 3.36 \\ Coated 12 months \({}^{\text{B}}\) & 3.01 & 14.36 \({}^{\text{cde}}\)\(\pm\) 0.27 & 34.13 \({}^{\text{cde}}\)\(\pm\) 4.06 \\ Coated heat shock \({}^{\text{A}}\) & 3.01 & 31.45 \({}^{\text{cde}}\)\(\pm\) 2.77 & 24.03 \({}^{\text{cde}}\)\(\pm\) 2.48 \\ Coated heat shock 12 months \({}^{\text{B}}\) & 3.01 & 12.73 \({}^{\text{dde}}\)\(\pm\) 1.87 & 21.38 \({}^{\text{cde}}\)\(\pm\) 1.41 \\ Coated pH shock \({}^{\text{A}}\) & 3.05 & 31.00 \({}^{\text{cde}}\)\(\pm\) 1.77 & 36.22 \({}^{\text{d}}\)\(\pm\) 2.44 \\ Coated pH shock 12 months \({}^{\text{B}}\) & 3.05 & 10.95 \({}^{\text{e}}\)\(\pm\) 1.24 & 17.02 \({}^{\text{d}}\)\(\pm\) 0.35 \\ \hline \hline \end{tabular}  
* \({}^{\text{A}}\) measured directly after drying/coating. \({}^{\text{B}}\) measured after 12 months of storage. Results are mean values of three repetitions \(\pm\) standard deviation. Values sharing the same lowercase letter are not significantly different (\(p\leq 0.05\)).  
\end{table} 
Table 4: Economic evaluation of different variants. Figure 4: Process flow diagram for fluid bed drying and coating of probiotics.