## 3 Results and Discussion  
### Composition Analysis  
The results of the proximate and structural composition analysis of DSG obtained from nine different distilleries are presented in Tables 2 and 3, respectively. The moisture content of fresh DSG ranged from 73.22 to 80.17%, ash content from 2.01 to 4.11%, extractives from 17.33 to 31.77%, crude protein from 12.38 to 26.32%, cellulose from 11.75 to 32.75%, hemicellulose from 6.97 to 19.47%, and lignin from 8.44 to 15.71%, while the total phenolic content ranged from 1.42 to 3.91 mg GAE/g. The results show that the samples varied widely in their composition and were significantly different (\(p<0.05\)), except for moisture and ash content. Several studies have also reported variations in spent grain composition. A comparison of spent grain composition from various studies is presented in Table 4.  
Due to its high moisture content, fresh DSG is very bulky and susceptible to rapid deterioration within five days, posing storage challenges. Therefore, fresh DSG must be stabilized to improve storage potential and facilitate its utilization. Drying is one of the most common methods employed to reduce moisture content, and bulk weight, and improve stability. However, drying is costly as it requires significant energy to evaporate water. Mechanical water removal processes, such as pressing, which require far less energy, can be employed before drying [38]. In mechanical pressing, fresh DSG is placed under a mechanical pressing device to expel some of the water and reduce the initial moisture content to about 31-43%, depending on the pressing duration and applied pressure [38]. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Sample Code** & **Moisture Content** & **Fat (\%)** & **Protein (\%)** & **Ash (\%)** & **Total Phenolics** \\  & **of Fresh DSG (\%)** & **Fat (\%)** & **Protein (\%)** & **Ash (\%)** & **MgGAE/g DSG** \\ \hline D1 & 80.17 \(\pm\) 1.57 \({}^{\text{a}}\) & 13.63 \(\pm\) 0.47 \({}^{\text{b}}\) & 17.93 \(\pm\) 1.06 \({}^{\text{c}}\) & 3.28 \(\pm\) 0.10 \({}^{\text{a}}\) & 2.25 \(\pm\) 0.17 \({}^{\text{ab}}\) \\ D2 & 75.54 \(\pm\) 0.593 \({}^{\text{b}}\) & 13.54 \(\pm\) 0.20 \({}^{\text{b}}\) & 18.28 \(\pm\) 0.67 \({}^{\text{bc}}\) & 3.95 \(\pm\) 0.32 \({}^{\text{a}}\) & 2.60 \(\pm\) 0.05 \({}^{\text{ab}}\) \\ D3 & 75.02 \(\pm\) 0.163 \({}^{\text{b}}\) & 10.98 \(\pm\) 0.57 \({}^{\text{c}}\) & 24.73 \(\pm\) 0.03 \({}^{\text{a}}\) & 3.53 \(\pm\) 0.51 \({}^{\text{a}}\) & 2.61 \(\pm\) 1.15 \({}^{\text{ab}}\) \\ D4 & 73.22 \(\pm\) 0.192 \({}^{\text{b}}\) & 10.01 \(\pm\) 0.02 \({}^{\text{cd}}\) & 18.46 \(\pm\) 0.05 \({}^{\text{bc}}\) & 3.69 \(\pm\) 0.06 \({}^{\text{a}}\) & 3.91 \(\pm\) 0.01 \({}^{\text{a}}\) \\ D5 & 75.7 \(\pm\) 0.367 \({}^{\text{b}}\) & 8.96 \(\pm\) 0.023 \({}^{\text{d}}\) & 20.32 \(\pm\) 0.65 \({}^{\text{b}}\) & 3.78 \(\pm\) 0.13 \({}^{\text{a}}\) & 3.37 \(\pm\) 0.46 \({}^{\text{a}}\) \\ D6 & 75.01 \(\pm\) 0.085 \({}^{\text{b}}\) & 13.49 \(\pm\) 0.29 \({}^{\text{b}}\) & 25.91 \(\pm\) 0.01 \({}^{\text{a}}\) & 4.11 \(\pm\) 0.06 \({}^{\text{a}}\) & 1.42 \(\pm\) 0.15 \({}^{\text{b}}\) \\ D7 & 73.49 \(\pm\) 0.645 \({}^{\text{b}}\) & 14.92 \(\pm\) 0.11 \({}^{\text{a}}\) & 18.25 \(\pm\) 0.21 \({}^{\text{bc}}\) & 3.64 \(\pm\) 0.47 \({}^{\text{a}}\) & 3.74 \(\pm\) 0.44 \({}^{\text{a}}\) \\ D8 & 74.71 \(\pm\) 0.760 \({}^{\text{b}}\) & 13.01 \(\pm\) 0.06 \({}^{\text{b}}\) & 12.38 \(\pm\) 0.98 \({}^{\text{d}}\) & 2.01 \(\pm\) 0.09 \({}^{\text{b}}\) & 2.27 \(\pm\) 0.01 \({}^{\text{ab}}\) \\ D9 & 74.95 \(\pm\) 0.487 \({}^{\text{b}}\) & 10.17 \(\pm\) 0.45 \({}^{\text{cd}}\) & 26.32 \(\pm\) 0.16 \({}^{\text{a}}\) & 3.21 \(\pm\) 0.11 \({}^{\text{a}}\) & 3.29 \(\pm\) 0.13 \({}^{\text{a}}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Proximate composition of DSG.