Engineering Biopolymer Hydrogels for 3D/4D Food Printing in Personalized Nutrition for Elderly Dysphagia Management

Introduction: As the population ages, dysphagia and sarcopenia have become significant nutritional challenges. Traditional texture-modified diets often reduce sensory quality, nutrient retention, and patient acceptance. Biopolymer hydrogels, such as protein–polysaccharide composites and bigels, combined with 3D/4D printing, can help create personalized, IDDSI-compliant foods that are both safe and functional. While previous reviews have examined printability, materials science, or elderly nutrition in isolation, none have brought together hydrogel design, 4D stimulus-responsiveness, and clinical nutrition goals.

Methods: Following PRISMA 2020 guidelines, this systematic review searched ScienceDirect, Scopus, and Web of Science for peer-reviewed English articles published from January 2020 to February 2025. The search used terms related to 3D/4D food printing, hydrogels, biopolymers, and nutrition for the elderly or people with dysphagia. Grey literature and non-peer-reviewed sources were not included.

Results and Discussion: Protein–polysaccharide hydrogels and bigels can be adjusted for rheology, porosity, and phase organization, which affect printability, bolus cohesion, and oral safety. 4D systems that use biopolymers responsive to pH, temperature, or moisture, such as anthocyanin-rich purple sweet potato and pea protein blends, can change shape, texture, and color to make foods safer to swallow and more appealing. Encapsulation methods such as Pickering emulsions and bigels help protect bioactive ingredients, such as curcumin and essential oils, by enabling controlled release in the digestive system and providing antioxidant and antimicrobial benefits important for older adults. Using AI to optimize ink formulations also improves batch-to-batch consistency.

Conclusions: Combining biopolymer hydrogel engineering with 4D stimuli-responsive design offers a practical approach to creating safe, nutrient-rich, and acceptable foods for the elderly and people with dysphagia. However, there are still important gaps, such as the need for standardized IDDSI texture measurements, clinical testing in older adults, and more data on storage and transport durability. These areas should be priorities for moving these technologies into clinical use.