A food for elders with dysphagia: Effect of sodium alginate with different viscosities on the gel properties of antarctic krill composite shrimp surimi

This study investigated the effects of sodium alginate (SA) with different viscosities on the physicochemical properties and structure of composite shrimp surimi gels made from Antarctic krill and Litopenaeus vannamei. Changes in texture, rheology, water status, thermal stability, chemical bonding, zeta potential, and microstructures of the gels were analyzed to explore their feasibility as food products for individuals with dysphagia. The addition of SA addition increased the chewiness, absolute value of zeta potential, WHC, and thermal stability of the composite shrimp surimi gels. Concurrently, it decreased the gel strength and the content of chemical bonds, such as ionic and hydrogen bonds, with these changes being more significant at higher SA viscosities. The water distribution analysis showed that increasing SA viscosity increased the content of immobilized water within the gels and stabilized the water. From the perspective of zeta potential and microstructure, higher SA viscosities significantly increased the absolute value of zeta potential, enhanced the electrostatic repulsion and spatial potential resistance, and resulted in larger microstructural gaps, which improved the moisture-trapping capacity and WHC of the gels. The microstructure was more homogeneous and continuous at an SA viscosity of 800 mPa s. International Dysphagia Dietary Standardization Initiative (IDDIS) testing showed that gels with added SA can be classified into Tier 6 dysphagia diets. These findings provide insights for developing nutritious dysphagia-suitable foods for elders.