Physicochemical, Sensorial and Calcium Bioavailability of Jelly Prepared Using Fish Gelatin in Combination with Furcellaran and Calcium L-Threonate

Confectionery products, specifically jelly and gummy, require optimized structural, thermal, and nutritional properties for functionality and consumer acceptance. This study investigated the impact of furcellaran (FUR) and calcium L-threonate (Ca) on the physicochemical and the sensory properties of fish gelatin-based jelly (JFG). Furcellaran modestly enhanced gel strength and hardness, while its combination with calcium L-threonate produced synergistic improvements, with JFG-FUR-Ca achieving the highest gel strength (947.63 g) and hardness (78.14 N). Microstructural and intermolecular force analyses indicated that Ca²⁺ bridging between gelatin and furcellaran promoted ionic and hydrogen bonding, forming a dense and thermostable network. The combined incorporation of furcellaran and calcium L-threonate enhanced the rheological properties while preserving low syneresis. Sensory evaluation revealed minor reductions; however, overall acceptability was higher than 7. Calcium bioavailability after digestion through the gastrointestinal tract model remained high (70–80%), confirming effective calcium fortification. The synergistic incorporation of furcellaran and calcium L-threonate effectively improved the structural integrity, thermal stability, and calcium bioavailability of fish gelatin-based jelly, while maintaining acceptable sensory qualities, highlighting its potential as a functional calcium-fortified confectionery product.