Effect of Sodium Alginate Addition on the Extrusion Characteristics of Soy Protein Concentrate

Plant-based meat was prepared from soy protein concentrate (SPC) with different proportions of added sodium alginate (SA) by twin screw high-moisture extrusion under varying die temperature. The macrostructure and microstructure of plant-based meat were characterized by texturization degree, chewiness, color, and scanning electron microscopy. The structural properties of the extrudates were investigated by specific mechanical energy, cooking characteristics, and water absorption capacity. The results showed that the addition of sodium alginate could improve the texturization degree and enhance the chewiness of extrudates. And all extruded samples obtained at a die temperature of 150 ℃ had a higher texturization degree. The specific mechanical energy and water absorption capacity showed that sodium alginate enhanced the protein-protein and protein-water interactions, and consequently increased the water holding capacity of the extrudates. Scanning electron microscopy showed that excessive sodium alginate caused the product to form a dense lamellar, non-fibrous structure. As a result, we found that extrudates with 6% SA had the most abundant fibrous structure and good cooking performance.