Different Alginate Spherification Methods for Producing Hydrogel Beads Loaded with Vitamins B9 and B12 to Support Hydration in Older Adults with Dysphagia

Abstract

Adequate hydration and nutrition are crucial for preventing health complications and functional decline in older adults, especially those with dysphagia. This study examined the use of direct frozen and reverse spherification, with different residence times, to create alginate-based, high-water-content (>95%) bite-sized structures that are safe to swallow and capable of encapsulating vitamins B9 and B12 for delayed release in the gastrointestinal tract. Residence time notably affected the beads’ microstructure and texture. Reverse-spherified liquid-core beads were soft and stable, maintaining high water content; however, they were not suitable for people with dysphagia because of their uneven texture and water release when compressed or bitten. Conversely, direct frozen spherification yielded solid-core alginate beads with low hardness (77.46–136.25 g), minimal adhesiveness (~11 g·s), good cohesiveness (>0.3), and rheological properties compatible with swallowing. A fiberoptic endoscopic swallowing assessment found that the patients rated these solid-core beads as easy to chew and comfortable to swallow. Over six weeks, vitamin retention was 59.4–79.4% for vitamin B9 and 69.6–97.0% for vitamin B12, with 80–90% released during simulated digestion. These results highlight frozen direct spherification’s potential to create dysphagia-friendly, high-water-content finger foods that improve hydration, nutrition, and vitamin encapsulation.