Development of soy protein isolate-based orally disintegrating films: The dual role of β-Cyclodextrin in enhancing disintegration performance and ergothioneine stability

Plant protein-based orally disintegrating films (ODFs) are promising but limited by slow disintegration and poor stability of incorporated actives. This study developed ergothioneine (EGT)-loaded soy protein isolate (SPI) ODFs and investigated the bifunctional regulatory effects of β-CD. β-CD exerts a dual role as both a structural modulator and a stability-enhancing additive. At 10% (w/w) dosage, β-CD remodeled the SPI network into a more hydrophilic structure, shortening in vitro disintegration time to 15.46 s and enhancing tensile strength to 12.15 MPa. Furthermore, β-CD incorporation was associated with improved retention of total antioxidant activity in EGT-loaded films during accelerated storage, likely attributable to reduced oxidative exposure via intermolecular interactions within the film matrix. Excessive β-CD (15%, w/w) induced phase separation and crystallization, impairing mechanical integrity and the observed antioxidant activity retention benefit. This work provides a strategy for developing plant protein-based oral delivery vehicles for sensitive nutraceuticals.