E-numbers / Flavour enhancers / E634
also: Calcium ribonucleotides · Calcium 5'-inosinate and 5'-guanylate
A mixture of calcium salts from natural nucleotides, added to deepen savoury taste without extra salt.
Scan a barcode to check a food for calcium 5'-ribonucleotides. NutraSafe Pro · £6.99/month · iOS
A flavour enhancer made by combining two calcium nucleotide salts: calcium 5'-inosinate (E633) and calcium 5'-guanylate.
A flavour enhancer made by combining two calcium nucleotide salts: calcium 5'-inosinate (E633) and calcium 5'-guanylate. Both nucleotides occur naturally in meat, fish, and mushrooms. In food production they are typically derived from fish, yeast extract, or fermentation of plant material.
Nucleotides like inosinate and guanylate bind to the same taste receptors on the tongue that glutamate activates. When used together or alongside monosodium glutamate (E621), they amplify the umami (savoury) taste sensation many times over. This synergy lets manufacturers achieve a full savoury flavour at lower total additive levels.
Instant noodles, crisps, flavoured snack foods, stock cubes, packet soups, ready meals, savoury sauces, and seasoning blends. On a label it appears as 'calcium 5'-ribonucleotides', 'E634', or sometimes listed alongside E621 (monosodium glutamate) and E631 (disodium inosinate).
Calcium 5'-ribonucleotides are broken down in the body to purines, which are metabolised into uric acid. For most people the amounts consumed from food additives are small relative to total dietary purine intake. However, people with gout or a tendency to form urate kidney stones are typically advised by clinicians to limit all sources of dietary purines, including nucleotide-based additives.
Dietary purines from nucleotides are metabolised to uric acid; elevated uric acid is the primary driver of gout flares and urate kidney stone formation.
Nucleotide additives such as inosinate and guanylate contribute to dietary purine load; clinicians commonly advise gout patients to limit nucleotide-rich foods and additives.
E634 is almost always derived from animal sources, primarily fish or meat processing by-products. It is therefore neither vegan nor suitable for most vegetarians. It is also not suitable for those following halal or kosher diets unless certified from an appropriate source. There is no requirement under UK or EU food law to declare the animal species source on the label.
Calcium 5'-ribonucleotides are commercially produced from fish, meat, or yeast; the species source is not required to be declared on the finished food label under current EU or UK additive labelling rules.
People with gout or a history of urate kidney stones should discuss limiting nucleotide additives with their doctor. Vegetarians, vegans, and people following halal or kosher diets should check with the manufacturer, as the source is not required on the label. Look for 'E634' or 'calcium 5'-ribonucleotides' in the ingredients list.
E634 is one of a family of nucleotide flavour enhancers that have been used in processed food since the 1960s. The science around them is well-established: they work by amplifying umami taste receptors, they are broken down in the body like any dietary nucleotide, and the main practical issue is their contribution to purine load for people prone to gout. There are no IARC classifications, no EU or UK bans or restrictions, and no endocrine or reproductive concerns in the published literature. The animal origin question is real but dietary rather than toxicological. For most people this is an ordinary ingredient; for gout sufferers or those with dietary requirements, the label term is the thing to check.
No. Calcium 5'-ribonucleotides are approved for use in the UK under the UK FSA's approved-additives list and the assimilated EU Regulation 1333/2008. It is permitted in most savoury food categories up to 500mg/kg.
E634 is broken down to purines, which raise uric acid levels. People with gout or urate kidney stones are usually advised to limit all dietary purines. Whether to avoid nucleotide additives specifically is a question to raise with a doctor or dietitian.
Crisps, flavoured snack foods, instant noodles, packet soups, stock cubes, ready meals, and savoury sauces are the most common sources. It often appears alongside E621 (monosodium glutamate) in the ingredients list.
Almost certainly not. Calcium 5'-ribonucleotides are commercially produced from fish or meat by-products in most cases. The species source is not required on the label, so vegans and vegetarians should contact the manufacturer directly or avoid products listing E634.
It's the only app that does thisUKJaneK
You Need This AppGmac2005
Best AppGK getting skinny UK App Store reviews
NutraSafe reads the label and puts every additive into plain English, with the source, right in the app.
NutraSafe Pro · £6.99/month · iOS
