Calcium guanylate

Calcium guanylate is the calcium salt of guanylic acid, providing umami flavour enhancement through the same nucleotide mechanism as disodium guanylate (E627) and other members of the guanylate family. Its use offers a pathway to flavour enhancement without adding sodium or potassium to the formulation, which can be advantageous in mineral-sensitive product categories. The calcium content also contributes a trace nutritional benefit relative to sodium-based alternatives.

JECFA evaluated calcium guanylate as part of the guanylate additive group in 1987 and assigned a "not specified" ADI, reflecting the normal metabolic role of guanosine monophosphate in cellular function and the nutritional essentiality of calcium. No toxicological concern has been identified at levels used in food products.

Calcium guanylate is approved in the EU and in other major food markets for use as a flavour enhancer. The principal consumer advisory for this additive, as for all guanylate and inosinate enhancers, is the purine content: guanylate compounds are broken down to uric acid in the body, and consumers with gout or urate metabolism disorders should treat E629 with the same caution as other nucleotide enhancers. In practice, calcium guanylate appears less frequently on food labels than the sodium and disodium forms, but the physiological effect and dietary consideration are equivalent. It is typically used in combination with glutamate enhancers to maximise umami synergy.