## 3 Results and Discussion
### Effect of Drying on Cassava Leaves Quality
#### 3.2.2 Effect of Drying Temperatures on Cassava Leaves Quality  
Table 2 presents the drying time, moisture content, water activity, and the percentage of remaining components of cassava leaves dried at different temperatures using a cabinet dryer. Drying cassava leaves at 40 \({}^{\circ}\)C required 14 h to achieve a \(\mathrm{a_{w}}\) less than 0.6, whereas drying at 80 \({}^{\circ}\)C reduced the drying time by more than 90%. The final moisture content of the dried leaves ranged from 6.41 to 8.93% w.b., with \(\mathrm{a_{w}}\) between 0.41 and 0.56. Leaves dried at higher temperatures had lower final moisture and \(\mathrm{a_{w}}\) compared to those dried at lower temperatures. This was because the drying process was stopped when the midribs of the leaves became dry and brittle, which may be attributed to the over-drying of the lamina leaf area. Cyanide is the natural toxin which limited the use of cassava leaves for human consumption. The total cyanide content in dried cassava leaves decreased as the drying temperature increased. Although higher temperatures can reduce the cyanide content, they can also lead to the degradation of other nutrients and bioactive compounds. Leaves dried at 40 \({}^{\circ}\)C retained 82.46% of cyanide (1084.55 \(\pm\) 165.55 mg/kg), while at 80 \({}^{\circ}\)C, only 37.40% (490.86 \(\pm\) 52.36 mg/kg) persisted. These results are consistent with previous studies showing lower cyanide content at higher temperatures and longer drying times [29; 30]. Temperature was identified as the primary factor influencing the cyanide content. This study demonstrated that drying alone might not sufficiently reduce cyanide content to the recommended safe level of 10 mg/kg for human consumption, as suggested by FAO/WHO [31]. Therefore, additional cooking or processing of dried cassava leaves before consumption is necessary. Moreover, a long drying process at low temperatures may not effectively prevent mold formation and could result in significant nutrients and bioactive compounds loss. At drying temperatures of 70 and 80 \({}^{\circ}\)C, the vitamin C content remained relatively high, retaining 88.15% and 106.60% of the levels found in fresh leaves, respectively. In contrast, drying at lower temperatures, which required a longer duration, significantly reduced vitamin C content. At 40 \({}^{\circ}\)C, only 29.25% of the vitamin C content remained. These findings highlight that the drying time significantly impacts the degradation of vitamin C in cassava leaves. Similar results have been observed in previous studies, showing higher losses of vitamin C occur when drying cabbage outer leaves at lower temperatures and for longer durations [32]. [PERSON] et al. [33] reported that tea leaves dried at 80 \({}^{\circ}\)C retained more vitamin C than those dried at 60 \({}^{\circ}\)C or sun-dried. Dried Gill greens at 50 \({}^{\circ}\)C retained 81.37% of the vitamin C content compared to fresh samples [34]. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{ \begin{tabular}{c} **Drying** \\ **Temperature-** \\ **atures** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **Time** \\ **(h:min)** \\ \end{tabular}  } & \multirow{2}{*}{\ \begin{tabular}{c} **Moisture** \\ **(\% w.b.)** \\ \end{tabular}  } & \multirow{2}{*}{ \begin{tabular}{c} **Aw** \\ **(\% w.b.)** \\ \end{tabular}