## 3 Results and Discussion
### Chemical Analysis During Storage of BSG and SCG  
The results of the chemical analysis of pH and moisture content of BSG and SCG subjected to storage for up to 14 days in aerobic trays and anaerobic drums are shown in Figure 1.  
The pH of BSG in trays continuously increases from the initial value of 4.7 to 6.9 \(\pm\) 0.1, with no significant difference between the two trays at day 14, as seen in Figure 1a. The increasing pH in trays is thought to be linked to the observed fungal growth, as fungi with high proteolytic activity can cause ammonia formation on extended solid-state fermentation [56]. In contrast, BSG stored in drums exhibits a slight drop in pH already at day 3 to 4.2 \(\pm\) 0.5 to 4.3 \(\pm\) 0.6, which appears to be stable over the course of the storage up to 14 days. The rapid decrease in pH by day 3 is thought to be caused by the proliferation of LAB and the generation of lactic acid from the metabolism of fermentable sugars, similar to many traditional fermented foods [57]. The higher variability of pH in drums reflects larger differences in measurements between the vertically separated sampling positions, in contrast to the laterally separated samplings for trays. \begin{table}
\begin{tabular}{c c} \hline \hline
**Type of Microorganism** & **Identified Species** \\ \hline \multirow{3}{*}{Aerobic bacteria} & _Bacillus subtilis_ \\  & _Bacillus spizzenii_ \\  & _Bacillus rugosus_ \\ \hline \multirow{3}{*}{Anaerobic bacteria} & _Enterococcus durans_ \\  & _Cronobacter malonicus_ \\ \hline \multirow{3}{*}{Lactic Acid Bacteria} & _Pediococcus acidlactici_ \\  & _Enterococcus ficeium_ \\  & _Limosilactobacillus fermentatum_ \\ \hline \multirow{3}{*}{Yeast} & _Candida tropicalis_ \\  & _Pichia kudriawzevi_ \\  & _Kluyveromyces marxiamus_ \\ \hline Fungi & - \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Identification of isolated microorganisms in BSG by Sanger sequencing. The moisture content for BSG is shown in Figure 1b, and storage on trays shows no significant difference from the initial 70% value at day 3, but then the moisture content lowers over the course of storage with significant differences between the two trays of 35 \(\pm\) 7% and 58 \(\pm\) 8%. The BSG in trays apparently dries out under ambient conditions (ca. 30 \({}^{\circ}\)C; 70% to 80% RH). In contrast, the BSG stored in drums shows no significant difference in moisture content during storage, maintaining a stable moisture content across the trials of 76 \(\pm\) 3%. The slightly elevated moisture content compared to the initial 70% is likely caused by free water draining towards the bottom of the drum due to gravity flow and may be the fundamental cause of the observed differences in pH. Figure 1c,d show the pH and moisture content of SCG stored in trays and drums. The moisture content in trays declines slightly from the initial value of 56% to 50 \(\pm\) 3%, suggesting this material is more resistant to drying compared to BSG. SCG stored in drums show a slight but insignificant increase from 48% to 52 \(\pm\) 9% and 56 \(\pm\) 13%, similar to BSG  
Figure 1: Chemical analysis on wet matter basis of BSG and SCG during storage in trays (BSG-2 and SCG-2) and drums (BSG-2 and SCG-3): (**a**) pH of BSG in a 50 wt% solution; (**b**) moisture content of BSG; (**c**) pH of SCG in a 50 wt% solution; (**d**) moisture content of SCG. in drums. In trays, the pH at day 3 is similar to the initial value of 5.8 but then gradually drops to finally reach 5.1 \(\pm\) 0.1 to 5.2 \(\pm\) 0.1, presumably due to the production of organic acids such as acetate and lactate by bacteria. With respect to pH, SCG in drums had a lower initial pH of 4.8 and showed larger variability in final values compared to BSG, with a final pH of 4.4 \(\pm\) 0.3 and 4.6 \(\pm\) 0.6. The SCG in trays did not show the same trend of increase in pH and decrease in MC as BSG.