## 3 Results and Discussion
### Evaluation of Antioxidant Activities  
#### 3.4.1 Total Phenolics and Total Flavonoids Contents  
The data regarding the inter-varietal variation in the amount of TPC and TFC are discussed in Table 1. Total phenolic contents were expressed in mg/g of dry material measured as gallic acid equivalent (GAE). Total phenolic contents were ranged from 9.7 to 32.8 mg/g of dry weight of plant material measured as GAE. Maximum TPC were observed in red cabbage extract (32.8 mg/g of dry weight of plant material measured as GAE).  
Figure 1: Typical HPLC chromatogram, showing the separation of phenolic acids and flavonoids in red cabbage extract.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Compounds**} & \multicolumn{5}{c}{**\% Composition**} \\ \cline{2-6}  & **Cauliflower** & **Broccoli** & **Red Cabbage** & **White Cabbage** & **Chinese Cabbage** \\ \hline Maltodextrose & 83.31 \(\pm\) 4.99 \({}^{\text{c,d}}\) & 77.45 \(\pm\) 4.65 \({}^{\text{c}}\) & 86.73 \(\pm\) 5.21 \({}^{\text{d}}\) & 52.52 \(\pm\) 3.15 \({}^{\text{a}}\) & 66.81 \(\pm\) 4.01 \({}^{\text{b}}\) \\ Maltose & 2.32 \(\pm\) 0.14 \({}^{\text{c}}\) & 1.48 \(\pm\) 0.08 \({}^{\text{a}}\) & 2.03 \(\pm\) 0.12 \({}^{\text{b}}\) & 4.90 \(\pm\) 0.29 \({}^{\text{d}}\) & 1.74 \(\pm\) 0.11 \({}^{\text{a}}\) \\ Glucose & 2.89 \(\pm\) 0.17 \({}^{\text{a}}\) & 4.71 \(\pm\) 0.28 \({}^{\text{b}}\) & 4.91 \(\pm\) 0.29 \({}^{\text{b}}\) & 11.99 \(\pm\) 0.72 \({}^{\text{d}}\) & 9.02 \(\pm\) 0.54 \({}^{\text{c}}\) \\ Fructose & 11.47 \(\pm\) 0.68 \({}^{\text{b}}\) & 14.47 \(\pm\) 0.87 \({}^{\text{c}}\) & 5.32 \(\pm\) 0.32 \({}^{\text{a}}\) & 28.64 \(\pm\) 1.72 \({}^{\text{e}}\) & 22.45 \(\pm\) 1.35 \({}^{\text{d}}\) \\ \hline \hline \end{tabular}  
* The values are mean \(\pm\) standard deviation of three independent observations. Different letters in superscript show significant differences among selected _Brassic_ species.  
\end{table}
Table 3: Sugar composition of selected _Brassica_ species.  
GAE) while the minimum TPC were observed in Chinese cabbage extracts (9.7 mg/g of dry weight of plant material measured as GAE). Total flavonoid content, expressed in mg/g of dry material, was measured as catechine equivalent (CE). TFC were ranged from 7.7 to 23.7 mg/g of dry weight of plant material measured as CE. Maximum TFC were also found in red cabbage extract (23.7 mg/g of dry weight of plant material measured as CE) while the minimum was found in Chinese cabbage extracts (7.7 mg/g of dry weight of plant material measured as CE) in comparison with the five selected varieties of _Brassica_ genus as shown in the Table 1. Statistical analysis exhibited that the different extracts of selected species of _Brassica_ genus exert a potential effect (\(p<0.05\)) on total phenolic contents and total flavonoids contents. Many studies confirmed that the composition and amount of phenolics and flavonoids contents varies among different species and within the sub-cellular and tissues level [23]. Our results are contrary to the results reported earlier on the TPC and TFC. A previous report published by [PERSON] et al. [19; 24], reported the TPC (29.13 and 21.38) and TPC (17.44 and 12.33) for red cabbage and white cabbage extract, respectively. Another report, published by [PERSON] et al. [25], showed that TPC of Chinese cabbage, broccoli, white cabbage and cauliflower extract were 0.21, 1.06, 0.35 and 0.57 mg/g dry weight, respectively. The difference in the TPC and TFC in our results and in the previous published reports might be due to the difference in extraction temperature, handling techniques, agro-climatic, geographical and seasonal condition in which they are grown [20].