Development of texturized legume protein from peas (Pisum sativum L.) and shiitake mushroom (Lentinus edodes P.): optimization and characterization approach

The development of texturized legume proteins (TLP), especially from pea proteins is influenced by the globular nature of plant proteins, which can hinder the formation of fibrous structures. This study demonstrated that optimised extrusion conditions effectively enhanced the fibrous structure of texturized pea-shiitake mushroom (TPSM) protein using a single-screw extrusion process. A Box–Behnken design under response surface methodology was applied to optimise feed mixtures composition (pea protein isolate (PPI) and shiitake mushroom (SM)), barrel temperature, and screw speed. The optimal conditions identified were 80.91% PPI, 19.09% SM, a barrel temperature of 150 °C, and a screw speed of 151.41 rpm. These conditions significantly influenced the integrity index (II) and water absorption capacity (WAC), with barrel temperature being the most influential factor. Increasing barrel temperature improved both II and WAC, contributing to enhanced texturization. Chemical analysis revealed a protein content of 73.49 ± 0.3% in TPSM, with a favourable amino acid profile following extrusion. Protein solubility decreased significantly after extrusion. Functional analysis showed a significantly higher WAC, a significantly lower oil absorption capacity, no gelling formation at concentration 2–20% (w/v), and no significant effects on foaming and emulsification properties. These findings provide insights into optimising plant-based protein texturization for improved functionality in alternative protein applications.