Yeast protein-based high-moisture extrudates mimicking chicken breast in structural and digestive properties

Yeast protein (YP) is a "complete" protein with the nutrition to potentially replace animal-based meat. This study improved YP-based (60-70%) high-moisture extrudates with amylose/amylopectin (10%) to mimic chicken breast texture and characterized their differences of nutritional properties. The 60% YP extrudates with amylopectin (YP-60-P) achieved optimal structural properties with chicken breast in fibrous degree, hardness, resilience, and chewiness through amylopectin-mediated stress reduction and shear resistance enhancement during high-moisture extrusion, while 70% YP extrudates underperformed. Dynamic in vitro digestion models demonstrated that the higher apparent viscosity and viscoelasticity of YP-60-P digesta delayed gastric emptying, while structural disintegration of digesta further accelerated digestion kinetics. Despite 8.52% lower overall digestibility, YP-60-P showed 13.78% higher essential amino acid bioaccessibility than chicken breast post-digestion. Peptidomic analysis confirmed superior production of low-molecular-weight peptides in YP-60-P, indicating enhanced nutritional bioavailability. These findings advance the design of nutritionally optimized, texture-accurate YP meat analogues.