Changes in starch-assisted expansion porous structure of peanut protein via extrusion and impact on textural and rehydration properties

Extruded restructured plant proteins for foods are beneficial towards environmental sustainability. Peanut protein is a high-quality source of plant protein that can be utilized towards this goal. However, control of pore structure during extrusion is challenging, leading to poor texture and rehydration properties. In this study, blends of peanut protein and pea starch were subjected to extrusion processing at pea starch inclusion levels of 0 %, 10 %, 15 %, 20 %, 25 %, and 30 % (w/w) to fabricate extrudates possessing a porous structure. Results showed that increased pea starch content raised the expansion ratio of the peanut protein extrudates from 1.47 to 2.80, creating larger pores. This promoted faster water absorption by the extrudates. Protein and starch interacted through hydrogen bonds and hydrophobic interactions, influencing disulfide bonds and free sulfhydryl groups. Higher pea starch content increased protein-starch interactions, resulting in polymer systems with higher viscosity. The results explained the influence of the porous structure of peanut protein and pea starch on the extrudate’s textural and rehydration properties during extrusion.