## 3 Results
### Statistical Analysis and Fitting of Model of Encapsulation Efficiency
\begin{table}
\begin{tabular}{c c c c c c c} \hline \multirow{2}{*}{**Run No.**} & \multicolumn{4}{c}{**Coded Variables**} & \multicolumn{4}{c}{**Response**} \\ \cline{2-7}  & \(\mathbf{X_{1}}\) & \(\mathbf{X_{2}}\) & \(\mathbf{X_{3}}\) & \(\mathbf{X_{4}}\) & \(\mathbf{X_{5}}\) & **Encapsulation Efficiency (\%)** & **Water Absorption (\%)** \\ \hline
1 & 0 & 0 & 0 & \(-1\) & +1 & 84.34 & 66.9 \\
2 & 0 & 0 & 0 & +1 & \(-1\) & 96.35 & 84.5 \\
3 & +1 & +1 & 0 & 0 & 0 & 77.19 & 239.5 \\
4 & \(-1\) & \(-1\) & 0 & 0 & 0 & 51.06 & 135.9 \\
5 & 0 & 0 & 0 & 0 & 0 & 82.79 & 227.1 \\
6 & 0 & 0 & 0 & 0 & 0 & 89.84 & 187.8 \\
7 & 0 & 0 & +1 & \(-1\) & 0 & 97.62 & 95.9 \\
8 & 0 & \(-1\) & 0 & \(-1\) & 0 & 59.66 & 137.8 \\
9 & 0 & 0 & \(-1\) & +1 & 0 & 98.62 & 78.6 \\
10 & +1 & 0 & +1 & 0 & 0 & 56.19 & 196.8 \\
11 & +1 & 0 & 0 & +1 & 0 & 96.59 & 109.2 \\
12 & 0 & 0 & 0 & 0 & 0 & 79.45 & 186.9 \\
13 & +1 & \(-1\) & 0 & 0 & 0 & 83.74 & 149.3 \\
14 & \(-1\) & +1 & 0 & 0 & 0 & 66.82 & 109.4 \\
15 & 0 & +1 & 0 & +1 & 0 & 92.4 & 119.9 \\
16 & 0 & 0 & 0 & 0 & 0 & 88.61 & 192.2 \\
17 & \(-1\) & 0 & 0 & 0 & +1 & 82.78 & 77.6 \\
18 & 0 & 0 & \(-1\) & 0 & +1 & 73.1 & 84.3 \\
19 & 0 & +1 & 0 & 0 & +1 & 76.18 & 148.3 \\
20 & 0 & 0 & 0 & 0 & 0 & 91.95 & 204.5 \\
21 & \(-1\) & 0 & 0 & 0 & \(-1\) & 47.69 & 105.6 \\
22 & 0 & +1 & 0 & 0 & \(-1\) & 67.95 & 90.4 \\
23 & 0 & 0 & \(-1\) & 0 & \(-1\) & 82.82 & 142.9 \\
24 & 0 & 0 & +1 & +1 & 0 & 93.41 & 63.7 \\
25 & 0 & \(-1\) & 0 & 0 & \(-1\) & 78.53 & 87.2 \\
26 & 0 & +1 & +1 & 0 & 0 & 98.25 & 158.7 \\
27 & \(-1\) & 0 & \(-1\) & 0 & 0 & 56.91 & 130.2 \\
28 & 0 & 0 & +1 & 0 & \(-1\) & 75.45 & 168.4 \\
29 & +1 & 0 & 0 & \(-1\) & 0 & 69.38 & 100.8 \\
30 & 0 & \(-1\) & -1 & 0 & 0 & 90.24 & 106.4 \\
31 & 0 & \(-1\) & 0 & 0 & +1 & 71.3 & 97.6 \\
32 & 0 & 0 & 0 & \(-1\) & -1 & 87.61 & 161.2 \\
33 & \(-1\) & 0 & 0 & +1 & 0 & 62.16 & 87 \\
34 & +1 & 0 & \(-1\) & 0 & 0 & 70.1 & 145.3 \\
35 & 0 & 0 & \(-1\) & -1 & 0 & 56.87 & 82.3 \\
36 & \(-1\) & 0 & 0 & \(-1\) & 0 & 60.79 & 80.2 \\
37 & +1 & 0 & 0 & 0 & \(-1\) & 67.26 & 122.1 \\
38 & 0 & 0 & 0 & +1 & +1 & 87.28 & 53.1 \\
39 & 0 & 0 & 0 & 0 & 0 & 79.32 & 172.8 \\
40 & 0 & \(-1\) & 0 & +1 & 0 & 79.93 & 72.8 \\
41 & 0 & 0 & +1 & 0 & +1 & 88.13 & 63.7 \\
42 & 0 & +1 & 0 & \(-1\) & 0 & 55.1 & 93.5 \\
43 & +1 & 0 & 0 & 0 & +1 & 70.74 & 63.4 \\
44 & 0 & \(-1\) & +1 & 0 & 0 & 87.83 & 107.7 \\
45 & 0 & +1 & \(-1\) & 0 & 0 & 75.66 & 123.2 \\
46 & \(-1\) & 0 & +1 & 0 & 0 & 95.58 & 149.1 \\ \hline \end{tabular}
\end{table} 
Table 2: Effect of independent variables on responses. Encapsulation efficiency (Y\({}_{1}\)) and water absorption (Y\({}_{2}\)) of SCPU. D (CaCl\({}_{2}\) concentration) has a very significant effect on EE (\(p\) < 0.01), while item C (urea concentration) has a significant effect (\(p\) < 0.05). The interaction terms AC and CD have significant effects on EE (\(p\) < 0.01). The quadratic term A\({}^{2}\) has very significant effects on the results (\(p\) < 0.001), while other terms have no significant effect on EE (\(p\) > 0.05). The experimental results were statistically analyzed by Design Expert 10.0, and the second-order polynomial equation of the model was obtained. The equations, after eliminating non-significant items, are shown in Table 4. Positive signs indicate synergistic effects, while negative signs indicate antagonistic effects. The residuals normal plot, residuals vs. predicted plot, and predicted vs. actual plot of encapsulation efficiency model are shown in Figure 1. The normal plot of residuals is used to check whether the residuals follow a normal distribution, which is an important assumption in many statistical models [37]. The datapoints should follow a diagonal line representing the expected normal distribution. The results indicate that the residuals follow a normal distribution (Figure 1a). The plot of residuals vs. predicted values is used to check the assumption that residuals are randomly distributed around zero, with constant variance across all levels of the predicted values [38].