## 4 Discussion  
According to the sensory evaluation results, no significant difference was found in the outcomes of consumer evaluation, potentially due to a subtle difference hidden in black tea characteristics [16]. Research disclosed the relationship between the chemical components and sensorial attributes of black tea, i.e., an increase in amino acids and soluble sugar impart sweet, mellow, and refreshing features upon black tea [16]. This is why the sensory evaluation results reveal the change in taste from grassy, asringent, and bitter to sweet, mellow and refreshing as withering time increased. The decreasing trend in total polyphenols was due to the conversion of green tea catechins into black tea pigments [23]. Catechins are the richest polyphenols in green tea, reside in leaf mesophyll cells, impart the bitterness and asringent taste of tea brew [24; 25]. Throughout black tea processing, particularly during the withering stage, endogenous enzymes (POD and PPO) are triggered for the oxidation and dimerization of catechins (monomers) into dimeric compounds (theflavins) [1]. Flavonoids are a class of polyphenols prevalent in tea, such as flavonoids, flavanols (catechins), and oxidation products of catechins (theflavins, thebarubigins) [26]. The decreasing trend in flavonoids was possibly caused by the downregulation of differentially expressed genes (DEGs) involved in the biosynthesis of flavonoids during the withering process [8]. Tea polysaccharide (TPS) is a heteropolysaccharide containing polyphenol, pigment, and sugars, which is glycosidically conjugated to exhibit pharmacological activity [27]. The increasing tendency of polysaccharides might be due to the polycondensation of unprotected or dysfunctional monomers of TPS in the presence of glycosyltransferases [28]. Furthermore, the degradation of carbohydrates during withering intervened in the accumulation of polysaccharide contents [13]. Carbohydrates in the plucked leaves gradually hydrolyze to form simple sugars, and free amino acids react with simple sugars to develop the black tea flavor [29]. Therefore, the amount of soluble sugar increased, intensifying the sweet taste of black tea [16]. The increasing tendency of amino acids was due to the degradation of protein molecules by peptidase into simple amino acids; during the withering of black tea, protein reduced by about 1.2% of its total content [29]. The metabolism of free amino acids plays a \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & **DPPH IC\({}_{\textbf{50}}\)** & \multirow{2}{*}{\(\alpha\)-amylase IC\({}_{\textbf{50}}\)} & \multirow{2}{*}{\(\alpha\)-glucosidaseae} & **Glucose** \\  & **(ug/mL)** & & **(mg/mL)** & **IC\({}_{\textbf{50}}\) (ug/mL)** & **Uptake/\%** \\ \hline WT4 & 27.49 \(\pm\) 0.28 \({}^{\text{a}}\) & 17.97 \(\pm\) 0.10 \({}^{\text{a}}\) & 35.54 \(\pm\) 0.71 \({}^{\text{a}}\) & 54.29 \(\pm\) 1.57 \({}^{\text{c}}\) \\ WT6 & 28.63 \(\pm\) 0.21 \({}^{\text{b}}\) & 18.10 \(\pm\) 0.04 \({}^{\text{a}}\) & 36.55 \(\pm\) 0.86 \({}^{\text{ab}}\) & 57.43 \(\pm\) 1.43 \({}^{\text{d}}\) \\ WT8 & 29.48 \(\pm\) 0.18 \({}^{\text{c}}\) & 18.28 \(\pm\) 1.59 \({}^{\text{a}}\) & 37.38 \(\pm\) 0.31 \({}^{\text{b}}\) & 50.81 \(\pm\) 1.44 \({}^{\text{b}}\) \\ WT10 & 30.32 \(\pm\) 0.32 \({}^{\text{d}}\) & 18.37 \(\pm\) 0.04 \({}^{\text{a}}\) & 37.92 \(\pm\) 0.11 \({}^{\text{b}}\) & 46.36 \(\pm\) 1.20 \({}^{\text{a}}\) \\ WT12 & 32.29 \(\pm\) 0.65 \({}^{\text{e}}\) & 19.89 \(\pm\) 0.08 \({}^{\text{b}}\) & 39.67 \(\pm\) 1.36 \({}^{\text{c}}\) & 47.60 \(\pm\) 0.97 \({}^{\text{a}}\) \\ \hline DPPH, 2,-diphenyl-1-picrylhydraz; IC\({}_{50}\) indicates the scavenging or inhibitory concentration required to scavenge or inhibit 50%. The higher the IC\({}_{50}\) value, the lower the scavenging or inhibition potential and vice versa. Data are represented as mean \(\pm\) SD (\(n=3\)). Mean values with different superscripts down the column show a significant difference (\(p<\) 0.05). & & \\ \hline \hline \end{tabular}
\end{table}