## 3 Results and Discussion
### Preparation of Reaction Flavor Solution (RFS) for the Processing of green Laver Chip Products  
In this experiment, to mask the off-flavor of the green layer itself and improve the flavor, free amino acids and monosaccharides were selected as reaction flavor-inducing precursors, and their content ranges were selected through preliminary experiments to generate pyrazines with nutty odors and sulfur-containing compounds with meat-like odors [22; 26; 28]. The precursors of RFS processed to enhance the flavor of green layer chips were determined through a sensory evaluation (ranking test), with the results shown in Figure 4. First, four kinds of amino acids (threonine, proline, glycine, and methionine) and glucose were selected as precursors for RFS. Figure 4A shows the sensory evaluation results of RFS (Spl 1) made with three kinds of amino acids (glycine 0.7 g%, proline 0.5 g%, and threonine 0.5 g% \(w/v\)) and glucose (2 g%, \(w/v\)) and Spl 2 made with twice the concentration of Spl 1 (glucose was fixed at 2 g). Although there was no significant difference, Spl 2 was better. Compared to Spl 2, it was considered that the intensity of the odor of Spl 1 was slightly insufficient to mask the off-flavor of green layer chips. Next, we experimented by adding methionine, which is known to have a good effect in masking the characteristic odor of green layer and transforming it into a meat-like or savory \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Dependent Variables** & **Regression Model Equation** & **R2** & **\(p\)-Value** & **Lack of Fit** \\ \hline Y1 1 & 6.9061 \(-\) 0.2333X1 \(-\) 0.0815X2 2 & 0.8658 & 0.009 & 0.140 \\ Y2 2 & 6.4065 \(+\) 0.0829X2 \(-\) 0.0919X12 \(-\) 0.0775X2 2 & 0.8293 & 0.019 & 0.088 \\ \hline \multicolumn{4}{l}{Predicted and actual values} \\ \hline Independent variables & & Predicted value & & \\ \hline X1 3 & & 20 & & \\ X2 4 & & 80 & & \\ \hline Dependent variables & Predicted value & Experimental Value & \multicolumn{2}{l}{Absolute residual} \\ \hline Y1 & 7.64 & 7.00 \(\pm\) 0.74 5 & 8.43\% \\ Y2 & 5.50 & 5.89 \(\pm\) 0.59 6 & 7.07\% \\ \hline \multicolumn{4}{l}{1 Brittleness (N), 2 Overall acceptance, 3 green layer: surimi ratio (g%), 4 Heating time (s), 5 Mean \(\pm\) S.D. (\(n=11\)), 6 Mean \(\pm\) S.D. (\(n=3\)).} \\ \end{tabular}
\end{table} 
Table 3: Regression models derived through multiple linear regression analysis of dependent variables, and experimental value based on the result of RSM for making green layer chips. odor [26; 28] (Figure 4B). Compared to Spl 1 containing reaction precursors (proline 1.0 g, threonine 1.0 g, glycine 1.4 g, and glucose 2.0 g), Spl 2 (1.5 times the concentration of Spl 1), Spl 3 (concentration of Spl 1 + 0.05 g% methionine), and Spl 4 (concentration of Spl 2 + 0.05 g% methionine) were all significantly better (\(p<0.05\)), and among them, Spl 4 was the best. In Figure 4C, as a result of conducting a sensory evaluation on these RFS (a) and the green layer chips (b) prepared by adding these RFS, Spl 3a containing reaction flavor-inducing precursors (threonine 2.0 g%, proline 2.0 g%, glycine 2.8 g, methionine 0.05 g, and glucose 4 g) was the best, but Spl 1b (threonine 1.0 g, proline 1.0 g, glycine 1.4 g, methionine 0.05 g, and glucose 2 g) was the best when processed as a green layer chip. These results suggested that increasing the concentration of the added reaction flavor-inducing precursors negatively affected the odor and taste of the green layer chips. Next, roasted soybean powder (RSP) was added based on the results of Spl 1b in Figure 4C to reduce the off-flavor unique to green layer and further enhance the flavor. The sensory evaluation (9-point rating method) according to the concentration of added  
Figure 4: Determination of optimum content of reaction flavor solution (RFS) (**A–C**) and roasted soybean powder (RSP) (**D**) for the making of green layer chips.