Effect of reheating methods on the structural integrity and IDDSI compliance of multicomponent 3D-printed dysphagia-oriented foods

Despite the growing application of 3D printing in developing dysphagia-oriented 3D printed foods, there is a limited understanding of how storage and reheating impact their structural integrity and compliance with the International Dysphagia Diet Standardisation Initiative (IDDSI) Framework. This study investigated the effects of different reheating methods (steam oven, sous vide, and microwave oven) and nutritional compositions (protein: carbohydrate ratios) on the structural, textural and physicochemical properties of multicomponent 3D-printed foods aimed for Level 5 compliance. Reheated samples were assessed for shape fidelity, cooking loss, moisture loss, textural changes and IDDSI classification. Sous vide reheating best preserved shape integrity (Shape deviation (SD) ≤ 7.20 %), moisture content (77.71 ± 3.34 %), and desirable textural attributes of low hardness (13 ± 3.12 N), high cohesiveness (0.33 ± 0.11), and low adhesiveness (−0.47 ± 0.18 N), ensuring IDDSI compliance of Level 5 – minced and moist. In contrast, steam oven and microwave reheating led to significant structural deformation, moisture loss, and crust formation. Microwave-treated samples particularly exhibited high deformation (SD = 16–50 %) and were disqualified as per IDDSI criteria due to high hardness (18.46 ± 4.98 N), crust formation and low moisture content (69.75 ± 2.10 %). The findings highlight the critical influence of reheating methods on the safety and quality of 3D-printed dysphagia foods and provide a foundation for developing reheatable, IDDSI-compliant products for clinical and aged-care settings. • Multicomponent 3D-printed food reheated by steam oven, sous vide, microwave. • Sous vide reheated samples showed good shape fidelity, texture and IDDSI compliance. • Reheated samples complied with the IDDSI descriptors at Level 5 and Level 6.