# Effects of Different Pretreatments on the GABA Content of
## 3 Results and Discussion
### Effect of Various soaking Solutions on GABA and Antioxidants of Germinated Brown Rice  
According to previous studies, soaking treatment can increase GABA and bioactive compound content [34]. Table 2 indicates the GABA content of germinated brown rice after various soaking solutions. When unperminated, the Kaohsiung No. 145 brown rice contained only 7.10 mg/100 g of GABA. Following 42 h of germination treatment, the GABA content increased to 22.30 mg/100 g. Moreover, soaking treatments with 0.1% CaCl\({}_{2}\) and 0.1% glutamate (Glu) solutions further increased GABA content to 42.51 and 44.64 mg/100 g, respectively. However, when the soaking solution concentration was increased to 0.2%, GABA content decreased with no significant difference compared to the 42 h water germination, implying that the osmotic pressure of the solution may affect the activity of GABA decarboxylase, thereby influencing the biosynthesis of GABA.  
[PERSON] et al. [35] investigated the effect of various CaCl\({}_{2}\) concentrations on GABA content after germination in glutinous brown rice. The results revealed that soaking in 2.0% CaCl\({}_{2}\) for 24 h increased the GABA content by 1.76 times compared to the control group. However, increasing the concentration led to a decrease in GABA content, indicating that high CaCl\({}_{2}\) concentrations may inhibit the activity of glutamate decarboxylase and the metabolism pathway of GABA transaminase [36]. [PERSON] et al. [26] studied the effect of 0.1% and 0.2% soaking solutions (CaCl\({}_{2}\) and glutamic acid) on germinated brown rice from the Taichung  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Germination Treatment** & **GABA (mg/100 g)** \\ \hline Ungermination & 7.10 \(\pm\) 2.53 \({}^{\circ}\) \\ Water & 22.33 \(\pm\) 7.87 \({}^{\mathrm{b}}\) \\ \hline \multicolumn{2}{c}{Soaking} \\
0.1\% CaCl\({}_{2}\) & 42.51 \(\pm\) 11.37 \({}^{\mathrm{a}}\) \\
0.1\% Glu & 44.64 \(\pm\) 2.95 \({}^{\mathrm{a}}\) \\
0.2\% CaCl\({}_{2}\) & 30.09 \(\pm\) 9.51 \({}^{\mathrm{b}}\) \\
0.2\% Glu & 27.40 \(\pm\) 7.89 \({}^{\mathrm{b}}\) \\ \hline \hline \end{tabular} Data were expressed as mean and error bars of \(\pm\) S.D. (\(n=3\)). Means with different superscript letters in the same column are significantly different (\(p<0.05\)).  
\end{table}
Table 2: Effects of various soaking solutions on GABA content of germinated brown rice.  
Figure 3: Drying and temperature curves of 1 kg germinated brown rice during 35 \({}^{\circ}\)C cold air drying. Data were expressed as mean and error bars of \(\pm\) S.D. (\(n=3\)).  
Sen 10 variety. This variety had undetectable GABA content while ungerminated, although soaking in 0.2% CaCl\({}_{2}\) exhibited higher GABA content compared to the results of this experiment, indicating rice variety differences.  
Table 3 shows an analysis of the antioxidant components and DPPH radical scavenging capacity of germinated brown rice in various soaking solutions. The total phenolic content of germinated brown rice ranged from 0.85 to 0.93 mg gallic acid equivalent/g, with no significant differences observed following water germination and soaking in various solutions. Similarly, the flavonoid content ranged from 3.68 to 4.41 \(\upmu\)g quercetin equivalent/g, with no significant differences found. The DPPH radical scavenging capacity decreased from 87% to 84% after germination but increased to around 90% following soaking in various solutions. [PERSON] et al. [5] found a positive correlation between the antioxidant ability of phenolic compounds and their content during the brown rice germination process.