The effect of high pressure processing on pangasius sausages (Pangasianodon hypophthalmus) supplemented with seaweed (Undaria pinnatifida)

This study investigated the impact of high-pressure processing on Pangasianodon hypophthalmus sausages fortified with 2% Undaria pinnatifida under reduced salt conditions of 1% and 2% NaCl. Samples were subjected to 400 or 500 MPa at 10 °C for 10 min and evaluated for microbiological quality, color parameters, textural properties, water-holding capacity, protein solubility, structural modifications assessed by Fourier-transform infrared spectroscopy and SDS-PAGE, and microstructure examined by scanning electron microscopy. High-pressure treatment markedly decreased aerobic bacterial counts relative to thermally processed controls. In addition, pressure-treated samples exhibited enhanced whiteness, improved water retention, and superior gel strength and elasticity. Processing at 400 MPa produced a more uniform and compact gel matrix with greater mechanical integrity and brightness, whereas 500 MPa slightly reduced hardness and protein solubility, suggesting partial over-denaturation at higher pressure. Spectroscopic analysis indicated that high-pressure processing modulated protein secondary structure without disrupting the primary chemical framework, leading to a smoother and more cohesive microstructure compared with conventional heating. Overall, the combination of high-pressure processing and seaweed incorporation improved physicochemical and microbial quality while supporting sodium reduction, highlighting its potential for developing value-added Pangasius products.