## 3 Results and Discussion
### The Morpho-Textural Characteristic Changes
\begin{table}
\begin{tabular}{c c c c c c} \hline
**R-Stage** & **Processing** & \(L^{*}\) & \(a^{*}\) & \(b^{*}\) & **C** & **h** \\ \hline \multirow{4}{*}{G} & C & 55.6 \(\pm\) 0.9 a & \(-\)14.11 \(\pm\) 1.04 a & 16.0 \(\pm\) 1.7 a & 21.35 \(\pm\) 1.94 a & 131.4 \(\pm\) 0.9 c \\  & B & 60.5 \(\pm\) 0.2 b & \(-\)6.56 \(\pm\) 0.37 c & 19.1 \(\pm\) 1.9 b & 20.17 \(\pm\) 1.97 a & 109.0 \(\pm\) 0.7 a \\  & M & 60.1 \(\pm\) 0.1 b & \(-\)10.69 \(\pm\) 0.42 b & 19.7 \(\pm\) 0.3 b & 22.43 \(\pm\) 0.46 a & 118.4 \(\pm\) 0.6 b \\ \hline \multirow{4}{*}{Y} & C & 60.3 \(\pm\) 2.4 a & 52.53 \(\pm\) 2.48 b & 26.9 \(\pm\) 0.8 a & 59.03 \(\pm\) 2.08 a & 27.1 \(\pm\) 1.6 a \\  & B & 85.2 \(\pm\) 1.3 b & \(-\)4.65 \(\pm\) 0.18 a & 63.5 \(\pm\) 2.2 b & 63.63 \(\pm\) 2.14 b & 94.2 \(\pm\) 0.3 b \\  & M & 87.6 \(\pm\) 0.4 b & \(-\)3.62 \(\pm\) 0.38 a & 72.3 \(\pm\) 0.5 c & 72.35 \(\pm\) 0.55 c & 92.8 \(\pm\) 0.3 b \\ \hline \multirow{4}{*}{R} & C & 97.8 \(\pm\) 0.1 c & 10.75 \(\pm\) 0.10 a & 85.6 \(\pm\) 1.2 c & 86.23 \(\pm\) 1.16 c & 82.90 \(\pm\) 0.00 b \\  & B & 59.5 \(\pm\) 0.4 a & 43.16 \(\pm\) 0.33 b & 25.9 \(\pm\) 0.6 a & 50.34 \(\pm\) 0.57 a & 30.93 \(\pm\) 0.37 a \\ \cline{1-1}  & M & 60.7 \(\pm\) 1.0 b & 57.240.78 c & 40.6 \(\pm\) 11.8 b & 67.12 \(\pm\) 1.16 b & 31.45 \(\pm\) 0.44 a \\ \hline \multirow{4}{*}{R-stage Processing} & *** & *** & *** & *** & *** \\  & *** & *** & *** & *** & *** \\ \cline{1-1}  & *** & *** & *** & *** & *** \\ \hline \end{tabular}  
* R-stage—ripening stage; G—green peppers; Y—yellow pepper; R—red pepper; C—control; B—boiling; M—microwaving. Lowercase letters mean statistically significant difference between samples for same R-stage (\(p=0.05\)); ***—\(p<0.001\).  
\end{table} 
Table 4: Color change in bell peppers at different ripening stages after boiling and microwaving. In addition, a significant increase in the value of the \(b\) parameter was observed for yellow peppers as a result of cooking and microwaving (relative to the control). A significant decrease in the value of the \(b\) parameter was also observed for red peppers as a result of cooking and microwaving (relative to the control). No statistically significant changes were observed in the value of the C parameter as a result of cooking and microwaving green peppers (relative to the control). However, a statistically significant increase in the value of the C parameter was observed as a result of cooking and microwaving yellow peppers (relative to the control). In addition, a statistically significant decrease in the value of the C parameter was observed as a result of cooking and microwaving red peppers (relative to the control). In the case of yellow peppers, simultaneous increases in the \(L^{\star}\), \(b^{\star}\) and C\({}^{\star}\) parameters and decreases in the \(a\) parameter were observed, indicating that the application of both cooking and microwaving does not cause darkening of the surface tissues of this raw material. In the case of green peppers, an increase in the parameters \(L^{\star}\), \(b^{\star}\) and C\({}^{\star}\) was observed with an increase in the value of the parameter \(a\), indicating that the application of either cooking or microwaving does not cause such intense darkening of the surface tissues as in the case of yellow peppers. In the case of red peppers, a decrease in the parameters \(L^{\star}\), \(b^{\star}\) and C\({}^{\star}\) was observed with an increase in the value of the parameter \(a\), indicating that the application of cooking or microwaving can cause the surface tissues of red peppers to lighten. Statistical analysis confirmed that changes in color parameters depended both on the type of raw material (tested variety of bell pepper) and on the applied thermal processes. The observation we made may be due to differences in the susceptibility of the tested peppers to the inactivation of the enzyme system, which is responsible for the darkening of plant materials. Perhaps microwave radiation causes stronger (than green and yellow peppers) inactivation of polyphenol oxidase in red peppers.