## 3 Results and Discussion
### Yield  
Yield results are very important in determining the efficiency of the treatment applied in the manufacture of gelatin without neglecting other properties. The increase in yield value can be attributed to how much collagen is converted to gelatin. The use of strong bases or strong acids in the immersion/demineralization process can increase the presence of hydroxyl OH\({}^{-}\) ions or H\({}^{+}\) ions and accelerate the hydrolysis process. The faster the increase in the conversion of collagen to gelatin, the higher the yield obtained. Based on Table 1, it can be seen the effect of soaking NaOH with different concentrations and extraction times on the yield of beef bone gelatin. At the time of the extraction for 4 h, bone immersion with 4% NaOH produces gelatin with a yield of 10.391%. Immersion with 5% NaOH yield increased by 13.081%. The yield of gelatin with 6% NaOH immersion was 10.628%. This value seemed to decrease from the previous concentration. However, the immersion with 6% and 7% NaOH showed a decrease with a yield of 10.628% and 9.994%, respectively. The yield of cow bone gelatin at the time of the extraction for 6 h with 4% NaOH immersion was 11.141%. In immersion with 5% NaOH, the yield is 10.587%. This result shows a decrease from the previous concentration. On immersion with NaOH, 6% and 7% resulted in yields of 12.886% and 11.139%, respectively. Immersion with a concentration of 7% and 8% showed a significant increase from other concentrations. From these data, the effect of bone immersion with different concentrations of NaOH indicates a change in the yield (\(p\) < 0.05). The yield value seems to increase and decrease but tends to increase as the concentration of NaOH solution increases. This yield value is influenced by the washing process. With a high concentration of NaOH solution, some of the bone turns into bone powder and dissolves during the washing process using water. Osesein is also dissolved and wasted in this washing process which affects the reduced yield value of gelatin. However, changes in the shape of bone into powder or small flakes also affect  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Sample** & **Yield (\%)** & **Moisture (\%)** & **Ash (\%)** & **pH** & **Viscosity (\(\mathbf{c}\mathbf{P}\))** \\ \hline NaOH, 4 h & 11.13 \(\pm\) 1.16 & 7.13 \(\pm\) 1.68 & 0.60 \(\pm\) 0.15 & 6.15 \(\pm\) 0.04 & 2.51 \(\pm\) 0.15 \\ NaOH, 6 h & 12.61 \(\pm\) 2.76 & 6.06 \(\pm\) 3.03 & 0.65 \(\  
the increase in yield where the bone dissolved in aquated during extraction is not filtered well and is mixed with gelatin, allowing other minerals to be added to the yield value. Collagen that has undergone acid or alkaline soaking can dissolve in water, with this washing process with water has a relatively small effectiveness. The effect of extraction time on the yield of beef bone gelatin tends to increase. The yield with an extraction time of 6 h tends to be higher than the yield of gelatin with an extraction of 4 h. The highest yield value in 4 h extraction was 13,081% by immersion with 5% NaOH, while the yield at 6 h extraction was 17.294% immersion with 8% NaOH. This high yield value indicates the optimum concentration of NaOH immersion and optimum extraction time in the process of making gelatin using alkaline solvents. If using an acid solvent, the yield analysis, as shown in Figure 3, shows that there is an effect of soaking HCl with concentration and extraction time on the yield of cow bone gelatin (\(p<0.05\)). At the time of the extraction for 4 h, the HCl immersion resulted in the highest yield of bovine bone gelatin at 5% HCl concentration, which was 26.476%, and the relative yield decreased after that as the concentration increased. While the yield of cow bone at the extraction time for 6 h, the highest results were obtained at a 5% concentration of HCl immersion, namely 25.72%, but at other concentrations of HCl immersion, fluctuating results were obtained. The high yield is related to the amount of collagen that is converted to gelatin.