Physical property changes promoting shelf-life extension of soy protein-based high moisture meat analog under high pressure treatment

The effects of high pressure treatment were investigated on the physical properties and possible shelf-life extension of soy protein-based high moisture meat analog (S-HMMA) produced by the extrusion process. High pressure treatment was applied at 200, 400 and 600 MPa for 5, 10 and 15 min. Physical properties of S-HMMA including appearance, moisture content, color and texture were analyzed during storage at 4 °C for 8 weeks. Higher pressure and longer storage time significantly reduced moisture content by creating more air cells and increasing cavitation. L* value of S-HMMA products increased at higher levels of pressurization while increasing storage time tended to decrease lightness. The unpressurized control S-HMMA product showed increasing hardness and toughness, while S-HMMA products subjected to various pressures exhibited higher hardness and toughness over time compared to the control sample at 200–400 MPa. Products treated with high pressure (600 MPa) showed the highest reductions in microbial growth but the aroma of the beans became more pronounced.