## 3 Results and Discussion
### Optimum Conditions for Roasting  
The optimum conditions for roasting were analyzed using RSM. Temperature (X\({}_{1}\)) and heating time (X\({}_{2}\)) were set as independent variables, while overall acceptance (Y\({}_{1}\)) and hardness (Y\({}_{2}\)) were set as dependent variables. The model in this study was build using the actual value of independent variables. The model obtained for overall acceptance and \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Raw Materials**} & \multicolumn{3}{c}{**Drip Loss (\%)**} \\ \cline{2-4}  & **Room Temperature** & **Running Water** & **High-Frequency Defroster** \\ \hline AMPS & 8.15 \(\pm\) 0.07 \({}^{\text{a}}\) & 7.32 \(\pm\) 0.14 \({}^{\text{ab}}\) & 5.74 \(\pm\) 0.39 \({}^{\text{c}}\) \\ \hline CSM & 4.65 \(\pm\) 0.70 \({}^{\text{a}}\) & 2.80 \(\pm\) 0.60 \({}^{\text{ab}}\) & 2.20 \(\pm\) 0.80 \({}^{\text{b}}\) \\ \hline \hline \end{tabular} Data are presented as mean \(\pm\) SD. Different superscript letters (a–c) show significantly different values according to [PERSON]’s test (\(p<0.05\)).  
\end{table} 
Table 2: Drip loss analysis of frozen adductor muscle of the pen shell (AMPS) and common squid meat (CSM) under different conditions. hardness of AMPS was Y1 = 7.8097 + 0.9016X2 \(-\) 0.9525X12 \(-\) 1.4762X22 with 92.1% of R2, and Y2 = 471.5 + 63.588X1 + 28.777X2 + 79.759X12 + 46.134X22 with 95% of R2, respectively (Table 3). Three-dimensional response surface plots of AMPS showed an increase in the score of overall acceptance and decrease in hardness value with an increase in time and temperature until an optimum condition was attained (Figure 1a,b). The overall acceptance score started to decline beyond 217.8 \({}^{\circ}\)C and 1.08 min (Figure 1a), whereas the hardness value tended to increase by increasing the temperature and time beyond 217.8 \({}^{\circ}\)C and 1.08 min (Figure 1b). Therefore, the optimum temperature and time for the superheated steam roasting of AMPS were set at 217.8 \({}^{\circ}\)C for 1.08 min (Table 4). The CSM response surface model is displayed in Table 3. The model obtained for overall acceptance and hardness was Y1 = 8.07933 \(-\) 0.54590X2 \(-\) 0.76879X12 \(-\) 1.54254X22 with 91.6% of R2, and Y2 = 508.67 + 63.44X1 + 121.91X2 \(-\) 49.13X12 + 47.90X2 with 96.5% R2, respectively. Three-dimensional response surface plots of CSM for overall score and hardness (Figure 1c,d) showed the same pattern as those for AMPS. The overall acceptance score increased with the increasing time and temperature until the optimum condition was attained, while a reverse trend was observed for hardness. Increasing the temperature and time beyond 296.07 \({}^{\circ}\)C and 1.53 min decreased the overall acceptance scores (Figure 1c), while a temperature and time beyond 296.07 \({}^{\circ}\)C and 1.53 min increased the hardness (Figure 1d). The optimum temperature and time for CSM superheated steam roasting was 296.07 \({}^{\circ}\)C for 1.53 min (Table 4). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Raw Material** & **X1** **Temp (\({}^{\circ}\)C)** & **X2** **Time (min)** \\ \hline \multirow{4}{*}{AMPS} & Coded value & \(-\)0.1102 & 0.2435 \\  & Actual value & 217.80 & 1.08 \\ \cline{2-3}  & Predicted values & Y1: 7.9086, Y2: 421.1653 \\  & Experimental values & Y1: 7.83 \(\pm\) 0.55, Y2: 393.33 \(\pm\) 87.32 \\ \hline \multirow{4}{*}{CSM} & Coded value & \(-\)0.1964 & 0.0514 \\  & Actual value & 296.07 & 1.53 \\ \cline{1-1} \cline{2-3}  & Predicted values & Y1: 8.00, Y2: 500.00 \\ \cline{1-1}  & Experimental values & Y1: 8.07 \(\pm\) 0.15, Y2: 465.33 \(\pm\) 49.47 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Optimal cooking conditions of AMPS and CSM using response surface methodology (RSM)-analyzed superheated steam roasting.