# Antidiabetic, Anticolesterol, and Antioxidant Activity of
## 3 Results and Discussion
### Antioxidant Activity and the TPC of Fermented GB  
The antioxidant activities and TPC of fermented GB are shown in Table 3. The antioxidant activities of fermented GB were measured by three methods--DPPH radical scavenging activity is a measure of the degree to which stable DPPH radical is reduced by antioxidants with the electron-donating ability [35], and reducing power is a measurement the ability to reduce of the Fe\({}^{3+}\)/ferricyanide complex to the Fe\({}^{2+}\)/ferrous form in the presence of the reducer (i.e., antioxidants) [36]. DPPH radical scavenging activity expressed as EC\({}_{50}\) was significantly low in SKGB and SEGB (8.21 and 8.88 mg/mL), followed by that of LPGB (12.71 mg/mL), HAGB (17.05 mg/mL), and CON (19.60 mg/mL). Furthermore, the reducing power expressed as EC\({}_{50}\) was also significantly low in SKGB (0.29 mg/mL), followed by that of HAGB (0.69 mg/mL), SEGB (0.88 mg/mL), LPGB (0.94 mg/mL), and CON (2.06 mg/mL). The SOD-like activity is a measurement the inhibition of pyrogallol auto-oxidation, which is catalyzed by the superoxide radicals [37]. The SOD-like activity, expressed as IC\({}_{50}\), was significantly low in HAGB (22.37 mg/mL), followed by that of LPGB (30.51 mg/mL), SEGB (46.41 mg/mL), SKGB (49.79 mg/mL), and CON (67.34 mg/mL). During fermentation, the starter could enhance certain functionalities, such as the antioxidant activity, by degrading proteins, carbohydrates, and polyphenols, etc. from raw materials through microbial bioconversion [3]. _Bacillus_ spp. has an excellent ability to produce low-molecular weight functional compounds or peptides by decomposing high-molecular weight substances by secreting various hydrolysis enzymes [3]. On the other hand, facultative anaerobes such as _Lactobacillus_ spp. that grow in the presence of oxygen have enzymes such as SOD to remove free radicals produced by a reaction with oxygen [38]. Additionally, it has been reported that EPS produced by LAB has antioxidant activity like SOD [39]. For such a reason, in measuring the antioxidant activity of a mixed substance, it is important to evaluate the different mechanisms using several assays, rather than using only a single assay for the evaluation [40]. Some differences depend on the starter, but the overall fermented GB inoculated starter culture, especially SKGB and HAGB, exhibited good antioxidant activity compared to that of natural fermentation (CON).  
The TPC of fermented GB was also higher in the fermented GB inoculated starter culture (329.40\(-\)409.00 mg GAE/g) than in the CON (91.30 mg GAE/g). Polyphenols are known to be major indicators of antioxidant activity in soybean, fruits, vegetables, cereals, etc. According to [PERSON] et al. [41], the antioxidants present in edible insects are phenolic compounds, peptides, and un-identified components. Therefore, it can be predicted that the excellent antioxidant activity of the fermented GB combined with the starter is caused by high TPC, peptides, or uncertain components, which are increased by the starter.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **DPPH Radical** & **SOD-Like** & **Reducing** & **TPC** \\  & **Scavenging Activity** & **Activity** & **Power** & **(mg GAE/g)** \\  & **(EC\({}_{50}\) mg/mL)** & **(IC\({}_{50}\) mg/mL)** & **(EC\({}_{50}\) mg/mL)** & **(mg GAE/g)** \\ \hline CON & 19.60 \(\pm\) 3.94 a & 67.34 \(\pm\) 8.22 a & 2.06 \(\pm\) 0.30 a & 91.30 \(\pm\) 24.18 c \\ SKGB & 8.21 \(\pm\) 0.24 c & 49.79 \(\pm\) 6.85 a,b & 0.29 \(\pm\) 0.02 c & 367.50 \(\pm\) 3.13 a  \\ SEGB & 8.88 \(\pm\) 1.80 c & 46.41 \(\pm\) 2.64 b,c & 0.88 \(\pm\) 0.03 b & 393.21 \(\pm\) 30.81 a  \\ HAGB & 17.05 \(\pm\) 1.10 a,b & 22.37 \(\pm\) 0.54 d & 0.69 \(\pm\) 0.04 b & 329.40 \(\pm\) 7.64 b  \\ LPGB & 12.71 \(\pm\) 0.82 b,c & 30.51 \(\pm\) 3.06 c,d & 0.94 \(\pm\) 0.00 b & 409.00 \(\pm\) 16.00 a  \\ \hline \hline \end{tabular}
\end{table}
Table 3: Antioxidant activity and total phenolic compounds of fermented GB.