Xanthan gum and ovalbumin modulate the structural properties and starch digestibility of extruded chickpea noodles

Abstract

Chickpea is a promising ingredient for gluten-free staple foods, but its relatively weak structural integrity limits the quality of processed products. This study investigated the effects of xanthan gum (XG) and ovalbumin (OVA) on the thermomechanical properties, cooking quality, water distribution, texture, microstructure, and in vitro starch digestibility of twin-screw-extruded chickpea noodles. XG significantly enhanced dough water absorption and starch gelatinization, whereas OVA reduced water-holding capacity and more effectively inhibited starch retrogradation (p < 0.05). Without XG, increasing OVA from 0% to 15% decreased noodle water absorption from 61.20% to 43.45%. Both XG and OVA improved dough stability and markedly altered noodle expansion, moisture distribution, and textural properties. Notably, the combination of 1% XG and 5% OVA produced a relatively continuous and integrated gel structure and increased tensile distance to 6.63 mm. Microstructural analysis further demonstrated that XG and OVA modified the spatial organization and connectivity of the protein-rich phase, whereas excessive supplementation disrupted gel integrity through enhanced expansion. Starch digestibility was strongly formulation dependent. The 1% XG–5% OVA formulation exhibited a relatively low RDS content of 25.90% and a high RS content of 67.60%. These findings demonstrate that appropriate XG–OVA combinations can simultaneously regulate structural properties, processing quality, and starch digestibility of extruded chickpea noodles, providing a practical strategy for developing nutritionally improved gluten-free legume-based staple foods.