Development of easy-to-swallow and lipid-enhanced 3D printed surimi based on high internal phase emulsions

The elderly often suffered from chewing/swallowing difficulty, it is crucial to develop attractive dysphagia food. High internal phase emulsions (HIPEs) can be used as texture modifiers to create dysphagia food. Firstly, the multiple light scattering and micro-rheology results indicated that HIPEs stabilized by microbial transglutaminase (at 3.0 U/g) crosslinking of fish scale gelatin (FSG-TG-3) exhibited the highest stability. Subsequently, the effect of FSG-TG-3-stable fish oil HIPEs on the rheological properties, water distribution, 3D printability, textural properties, and swallowing behavior of surimi compared to the addition of fish oil were investigated. Results demonstrated that compared with oil-added group, HIPEs-added counterparts had relatively lower apparent viscosity, yield stress, and storage modulus, which was more suitable for 3D printing. Furthermore, the HIPEs addition effectively decreased the hardness and adhesiveness of the surimi gel, which could be classified into the level-6 (soft and bite-sized) diet in the International Dysphagia Diet Standardization Initiative (IDDSI) framework. However, the direct oil-added group not met the dysphagia diet because it returned its original shape when the fork was removed. Finally, we found that the internal structure of surimi-HIPEs was modified by controlling filling types and densities, which might be suitable for the elderly with different degrees of dysphagia. In summary, the surimi-HIPEs might could create attractive and lipid-enhanced 3D printed food for elderly with dysphagia.