Calcium alginate

Calcium alginate is the calcium salt of alginic acid (E400), notable for forming firm, stable, elastic gels at room temperature. Unlike sodium alginate which forms viscous solutions, calcium alginate creates solid gels used in restructured food products, fruit and vegetable analogues, wound dressings, and encapsulation applications. It is widely used in the food industry for forming spheres (spherification) in modernist cuisine.

JECFA's ADI is "not specified," evaluated in 1975. Calcium alginate is a non-absorbable dietary fibre that contributes a small amount of bioavailable calcium while passing through the gut. No adverse effects have been identified at any realistic dietary dose. The calcium content at food additive concentrations is nutritionally modest.

Calcium alginate is approved in the EU, US (GRAS), UK, Australia, and globally. It is found in restructured seafood products, certain confectionery, and as an encapsulation material for food ingredients. For healthy consumers there are no safety concerns. People with hypercalcaemia should monitor total calcium from all sources, though food additive amounts are not significant. It is one of the most naturally derived and well-tolerated gelling agents available.