Development of 3D printed pea protein isolate-based composite spinach as dysphagia diets

Driven by accelerating global population aging and muscle strength decline in elderly individuals, the demand for dysphagia diets is substantially increasing. 3D printing is equipped to process unpalatable pureed or thickened dysphagia diets into soft-textured and appealing foods tailored to personalized sensory preferences and nutritional requirements. This work explored the feasibility to develop 3D printed the texture-modified pea protein isolate (PPI)-based food as dysphagia diets, with incorporation of the spinach powder (SP) (12.5%, 25.0%, 37.5%, 50.0%, w/w). Results showed that SP incorporation optimized the printability, increased water-holding capacity, and facilitated intermolecular hydrogen bond formation, improving the rheological properties and texture characteristics of the PPI gel (control). Insufficient viscoelasticity and structural support in PPI and 12.5% SP-PPI inks prevented stable printed shape formation. The 25.0% SP-PPI and 37.5% SP-PPI inks possessed appropriate yield stress (168 Pa and 189 Pa, respectively) and shear-thinning behavior, delivering stable printed products. The 50.0% SP-PPI ink had excessive yield stress of 228 Pa, causing printing quality defects. Control and 12.5% SP-PPI inks lacked sufficient cohesiveness (0.654 and 0.688, respectively) and failed to pass the spoon tilt test. The 50.0% SP-PPI ink presented excessively high viscosity and hardness of 210.567 g and was unsuitable for dysphagia diets. The 25.0% and 37.5% SP-PPI inks passed the fork-spoon test, classified as Level 4 and Level 5 dysphagia diets, respectively, and their sensory qualities were more readily embraced. This work provides valuable insights for developing attractive, texture-modified and restructured plant-based dysphagia foods using 3D printing.