Modified wheat starch for the development of 3D-printed red propolis gels for dysphagic diets: phenolic content and bioactivities during in vitro gastrointestinal digestion

This study developed functional foods for dysphagic diets using Brazilian Red Propolis, modified starch, and 3D printing technology. The obtained gels were evaluated in relation to their printability, textures suitable for people with dysphagia, propolis phenolic bioaccessibility and bioactive properties. The gels were formulated using native and Dry Heating Treatment (DHT)-modified wheat starches (2 and 4 h), at 4-10 % concentrations, with propolis (4 %). Lower starch concentrations (≤6 %) led to agglomerates hindering 3D printing, while higher starch concentrations (8-10 %) produced homogeneous, printable gels. Fork test confirmed that DHT_2h 8 %, DHT_2h 10 %, DHT_4h 10 % gels met dysphagic criteria, and these 3D-printed gels were submitted to the in vitro digestion. Considering 60 % infill density (which showed the best results), consuming three cubes would deliver 500 mg propolis. In vitro gastrointestinal digestion demonstrated that the starch matrix stabilized phenolic compounds, with 10 % starch-propolis gels enhancing bioaccessibility and antioxidant activity. Anti-inflammatory tests revealed that starch alone had no effect, but propolis gels reduced NF-κB activation and pro-inflammatory cytokine release post-digestion, demonstrating anti-inflammatory potential. These highlight the synergy between 3D printing and functional ingredients, offering a promising approach for developing functional foods tailored to meet the specific dietary and health needs of dysphagic populations.