Hydrophobic plant protein-polysaccharide composite enables high moisture extrusion of anisotropic textures at low temperature

Abstract

The prevalent process of producing anisotropic high-moisture meat alternatives is to denature globular plant proteins at high temperatures and then deform the melt in the cooling die. In this study, we introduce an alternative approach that enables extrusion at a maximum barrel temperature of 80 °C: bond strengthening→contraction→plasticization→deformation. A formulation of zein and patatin-rich potato protein (75:25), pea starch, and high-acyl gellan gum was developed and extruded using a twin-screw setup with a cooling die, where barrel sections were maintained at 40–80 °C. The resulting composite material exhibited high anisotropy (anisotropic index up to 1.5), with gellan gum concentration significantly influencing both visual and measurable anisotropy. Molecular dynamics simulations revealed that heating promotes the elongation of zein molecules and their strong non-covalent interactions with HA-gellan gum and patatin via hydrogen bonding and electrostatic forces, leading to integration into a cohesive protein network. In contrast, starch remains predominantly at the surface, contributing to the smoothing and cohesive properties of the extrudate, highlighting the influence of ingredient interplay on extrudability and textural attributes. This novel approach demonstrates the feasibility of creating meat analogs with improved texture and reduced energy demands at up to 50 % lower temperatures, opening avenues for the inclusion of heat-sensitive ingredients.