Bioprinted living microalgae-laden polysaccharide-based hydrogels for easy-to-swallow alternative foods

Microalgae cultivation in hydrogels offers a promising solution to address water and arable land scarcity for enhanced agriculture efficiency and food production. However, such emerging culture system is often associated with tedious hydrogel dissolution and complex nutrient extraction, which limit the potential of microalgae as sustainable food resources. Herein, we develop a microalgae-laden polysaccharide-based hydrogels (MPHs), which can directly serve as easy-to-swallow nutritional alternative foods after cultivation without post-treatment. Specifically, microalgae are formulated with starch and carrageenan for MPHs, and the construction of living microalgal frameworks with customizable architectures enhances the light and water utilization, exhibiting significantly increased microalgal yield (9.1 ± 0.3 g L −1 ), 4.3 times higher than that of conventional liquid systems. Moreover, the MPH scaffold can be designed into various structures and shows high content of protein after cultivation, therefore emerging as easy-to-swallow foods for people with dysphagia. International Initiative for the Standardization of Dysphagia Diet (IDDSI) evaluation further confirms the hydrogel-like behavior aligned with IDDSI levels 5–7, highlighting its potential as structured alternative foods. This streamlined microalgae farming not only improves the efficiency of biosynthesis, but also democratizes access to nutritional food alternatives for food sustainability.