## 3 Results and Discussion
### Mechanical Properties  
The results of the mechanical properties of pangasius gel under different salt concentrations and HPP conditions are presented in Table 2. The hardness of the pangasius gel ranged from 7.93 N to 11.56 N. HPP increased the hardness of the pangasius gel with 2% added salt compared to HIGs (_p_ < 0.05). Notably, HPP pangasius gels with 1% added salt showed comparable hardness to the HIGs with 2% added salt (_p_ \(\geq\) 0.05). Thus, the hardness of the pangasius gel under reduced salt conditions remained equivalent to that of the HIG control with 2% added salt. Furthermore, treatment at 500 MPa/10 \({}^{\circ}\)C/10 min with 1% added salt exhibited hardness comparable to treatments at 300 MPa/10 \({}^{\circ}\)C/10 min with 2% salt and 400 MPa/10 \({}^{\circ}\)C/10 min with 2% salt. These findings align with previous studies demonstrating that HPP can reduce the required salt concentrations in barramundi [4] and Alaska Pollock surimi [5]. The increase in hardness of PC gels as compared to HIGs could be explained by the combined effects of pressure followed by heat treatment on protein denaturation and aggregation. HPP causes the partial unfolding of myofibrillar proteins, exposing hydrophobic groups and reactive sites for gelation, resulting in stronger protein-protein interactions after heating and the formation of a denser and more compact gel network [5]. HPP also dissociates actomyosin, increasing the content of myosin monomer for better gelation [11]. Furthermore, the formation of non-covalent bonds such bonds, and electrostatic interactions is also facilitated on protein denaturation and aggregation. HPP causes the partial unfolding of myofibrillar proteins, exposing hydrophobic groups and reactive sites for gelation, resulting in stronger protein-protein interactions after heating and the formation of a denser and more compact gel network [5]. HPP also dissociates actomyosin, increasing the content of myosin monomer for better gelation [11]. Furthermore, the formation of non-covalent bonds such as hydrophobic bonds, hydrogen bonds, and electrostatic interactions is also facilitated under high pressure. This could contribute to the improved hardness of the gel matrix [9]. In certain conditions, HPP also enhances the formation of disulfide bonds, especially with \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Treatment** & \begin{tabular}{c} **Hardness** \\ **(N)** \\ \end{tabular} & \
\begin{tabular}{c} **Springiness (mm)** \\ \end{tabular} &
\begin{tabular}{c} **Gel Strength** \\ **(N.mm)** \\ \end{tabular} \\ \hline HIGs & 7.93 \(\pm\) 0.64a & 0.88 \(\pm\) 0.02a & 346.21 \(\pm\) 16.96a \\ PG300/1% salt & 8.34 \(\pm\) 0.52a & 0.87 \(\pm\) 0.01a & 417.65 \(\pm\) 50.95b \\ PG300/2% salt & 10.39 \(\pm\) 1.68 bc & 0.89 \(\pm\) 0.02a & 424.85 \(\pm\) 25.29b \\ PG400/1% salt & 8.29 \(\pm\) 0.42a & 0.87 \(\pm\) 0.01a & 408.38 \(\pm\) 12.43b \\ PG400/2% salt & 10.32 \(\pm\) 0.87 bc & 0.88 \(\pm\) 0.02a & 436.92 \(\pm\) 42.25b \\ PG500/1% salt & 8.96 \(\pm\) 0.59 ac & 0.89 \(\pm\) 0.01a & 425.30 \(\pm\) 23.09b \\ PG500/2% salt & 11.56 \(\pm\) 1.76b & 0.89 \(\pm\) 0.02a & 464.92 \(\pm\) 13.56b \\ \hline \hline \end{tabular} HIGs: conventional heat induced gels; PG300/1%: salt concentration 1% and 300 MPa/10 \({}^{\circ}\)C/10 min; PG300/2%: salt concentration 1% and 300 MPa/10 \({}^{\circ}\)C/10 min; PG400/1%: salt concn-ration 1% and 400 MPa/10 \({}^{\circ}\)C/10 min; PG500/1%: salt concentration 1% and 500 MPa/10 \({}^{\circ}\)C/10 min; PG500/2%: salt concn-ration 1% and 500 MPa/10 \({}^{\circ}\)C/10 min. Different letters (a–c) in the same column indicate significant differences (_p_ < 0.05).  
\end{table} 
Table 2: Changes in the mechanical properties of Pegasus gels added 1 and 2% salt under different HPP treatments. conditions of heat following pressure treatment [34]. The compacted network formed through these interactions could exhibit higher hardness and gel strength.