Guanylic acid, 5'-

E number E626INS 626

Listed as a flavour enhancer by Codex.

Listed as flavour enhancers (Codex)

Guanylic acid is a savoury flavour enhancer, the mushroom counterpart to inosinate. Dried shiitake are rich in it, which is why drying mushrooms makes them taste more intensely of themselves than fresh ones do.

Where it is and isn’t permitted

Status of Guanylic acid, 5'- by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
Australia and New ZealandFood Standards Australia New ZealandNo listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it.
CanadaHealth CanadaNo listing matchedHealth Canada’s lists name additives without E or INS numbers, so this site matches them by exact name. A substance listed there under a name this site does not recognise has no row here.
European UnionEuropean Commission / EFSAPermitted, with conditions

70 food categories

Show every food category
  • 1.3 unflavoured fermented milk products heat-treated after fermentation — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 1.4 flavoured fermented milk products including heat-treated products — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 1.6.3 other creams — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 1.7.1 unripened cheese excluding products falling in category 16Permitted as a member of Group I, Additives. except mozzarella.
  • 1.7.5 processed cheese — several limitsPermitted as a member of Group I, Additives. except E 425 ML = 10000 mg/kg; E 620 to E 625, ML =10000 mg/kg individually or in combination, expressed as glutamic acid;E 626 to E 635, ML = 500 mg/kg individually or in combination, expressedas guanylic acid.
  • 1.7.6 cheese products (excluding products falling in category 16) — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 1.8 Dairy analogues, including beverage whiteners — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 10.2 processed eggs and egg products — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML =10000 mg/kg individually or in combination, expressed as glutamic acid;E 626 to E 635, ML = 500 mg/kg individually or in combination, expressedas guanylic acid.
  • 11.2 Other sugars and syrups — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 12.1.2 salt substitutes — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 12.1.2 salt substitutes — quantum satisPermitted as a member of Ribonucleotides. quantum satis.
  • 12.2.2 Seasonings and condiments — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 12.2.2 Seasonings and condiments — quantum satisPermitted as a member of Ribonucleotides. quantum satis.
  • 12.3 Vinegars and diluted acetic acid (diluted with water to 4-30 % by volume) — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 12.4 Mustard — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 12.5 Soups and broths — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 12.6 Sauces — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 12.7 Salads and savoury-based sandwich spreads — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 12.8 Yeast and yeast products — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 12.9 Protein products excluding products covered in category 1 8 — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 13.2 Foods for special medical purposes as defined by Regulation (EU) No 609/2013 (excluding products from food category 13.1.5.) — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 13.3 Total diet replacement for weight control food as defined by Regulation (EU) No 609/2013 — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 14.1.2 Fruit juices as defined by Directive 2001/112/EC and vegetable juicesPermitted as a member of Group I, Additives. only vegetable juices.
  • 14.1.3 Fruit nectars as defined by Directive 2001/112/EC and vegetable nectars and similar productsPermitted as a member of Group I, Additives. only vegetable nectars, E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.1.4 Flavoured_drinksPermitted as a member of Group I, Additives. E 420, E 421, E 953, E 965, E 966 and E 967 may not be used E 968 may not be used except where specifically provided for in this food category.
  • 14.1.5.2 otherPermitted as a member of Group I, Additives. excluding unflavoured leaf tea; including flavoured instant coffee; E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used in drinks.
  • 14.2.3 Cider and perryPermitted as a member of Group I, Additives. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.4 Fruit wine and made winePermitted as a member of Group I, Additives. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.5 MeadPermitted as a member of Group I, Additives. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.6 Spirit drinks as defined in Regulation (EU) 2019/787Permitted as a member of Group I, Additives. except whisky or whiskey; E 420, E421, E 953, E 965, E 966, E 967 and E 968 may not be used except in liqueurs.
  • 14.2.7.1 Aromatised winesPermitted as a member of Group I, Additives. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.7.2 Aromatised wine-based drinksPermitted as a member of Group I, Additives. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.7.3 Aromatised wine-product cocktailsPermitted as a member of Group I, Additives. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.8 Other alcoholic beverages including mixtures of alcoholic beverages with non-alcoholic beverages and other alcoholic beverages based on distilled alcohol with alcoholic strength by volume less than 15 %Permitted as a member of Group I, Additives. E 420, E421, E 953, E 965, E 966, E 967 and E 968 may not be used.
  • 15.1 Potato- cereal- flour- or starch-based snacks — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 15.2 Processed nuts — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 16 Desserts excluding products covered in category 1 3 and 4 — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 17.1 food supplements supplied in a solid form excluding food supplements for infants and young children’,Permitted as a member of Group I, Additives. E 410, E 412, E 415, E 417 and E 425 may not be used to produce dehydrated food supplements intended to rehydrate on ingestion.
  • 17.2 food supplements supplied in a liquid form excluding food supplements for Infants and young children — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 18 Processed foods not covered by categories 1 to 17 — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 18.1 Processed foods not covered by categories 18.2 and 18.3, excluding foods for infants and young children — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 18.2 Meal replacement for weight control as referred to in Commission Regulation (EU) No 432/2012 — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 18.3 Food specially produced to reduce the gluten content of gluten-containing ingredients or substitute the gluten-containing ingredientsPermitted as a member of Group I, Additives. Including dry pasta.
  • 2.2.2 Other fat and oil emulsions including spreads as defined by Regulation (EC) No 1234/2007 and liquid emulsions — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 2.3 Vegetable oil pan spray — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 3 edible ices — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 4.2.1 dried fruit and vegetablesPermitted as a member of Group I, Additives. E 410, E 412, E 415 and E 417 may not be used to produce dehydrated foods intended to rehydrate on ingestion.
  • 4.2.2 fruit and vegetables in vinegar oil or brine — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 4.2.4.1 fruit and vegetable preparations excluding compote — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 4.2.5.4 nut butters and nut spreads — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 4.2.6 processed potato products — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 5.1 Cocoa and chocolate products as covered by Directive 2000/36/ECPermitted as a member of Group I, Additives. only energy-reduced or with no added sugars.
  • 5.2 Other confectionery including breath freshening micro-sweetsPermitted as a member of Group I, Additives. The substances listed under numbers E 400, E 401, E 402, E 403, E 404, E 406, E 407, 407a, E 410, E 412, E 413, E 414, E 415, E 417, E 418, E 425 and E 440 may not be used in jelly mini-cups, defined, for the purpose of this Regulation, as jelly confectionery of a firm consistence, contained in semi rigid mini-cups or mini-capsules, intended to be ingested in a single bite by exerting pressure on the mini-cups or mini-capsule to project the confectionery into the mouth; E 410, E 412, E 415 E 417 may not be used to produce dehydrated foods intended to rehydrate on ingestion. E425 may not be used in jelly confectionery.
  • 5.3 chewing gum — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 5.4 Decorations, coatings and fillings, except fruit-based fillings covered by category 4.2.4 — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 6.2.2 starches — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 6.3 breakfast cereals — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 6.4.2 Dry pasta — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 6.4.4 Potato GnocchiPermitted as a member of Group I, Additives. except fresh refrigerated potato gnocchi.
  • 6.4.5 fillings of stuffed pasta (ravioli and similar) — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 6.5 Noodles — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 6.6 Batters — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 6.7 pre-cooked or processed cereals — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 7.1 Bread and rollsPermitted as a member of Group I, Additives. except products in 7.1.1 and 7.1.2.
  • 7.2 Fine bakery wares — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 8.3.1 Non-heat-treated processed meat — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 8.3.2 Heat-treated meat productsPermitted as a member of Group I, Additives. except foie gras, foie gras entier, blocs de foie gras, Libamáj, libamáj egészben, libamáj tömbben.
  • 8.3.3 Casings and coatings and decorations for meat — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 9.2 Processed fish and fishery products including molluscs and crustaceans — several limitsPermitted as a member of Group I, Additives. ML = quantum satis; except E 425 ML = 10000 mg/kg; E 620 to E 625, ML = 10000 mg/kg individually or in combination, expressed as glutamic acid; E 626 to E 635, ML = 500 mg/kg individually or in combination, expressed as guanylic acid.
  • 9.3 fish roePermitted as a member of Group I, Additives. only processed fish roe.
Regulation (EC) No 1333/2008, Annex IIand 69 further provisionsretrieved 2026-10-18
Great BritainFood Standards Agency / Food Standards ScotlandPermitted, with conditions

68 food categories

Show every food category
  • 1.3 Unflavoured fermented milk products, heat-treated after fermentationPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 1.4 Flavoured fermented milk products including heat-treated productsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 1.6.3 Other creamsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 1.7.1 Unripened cheese excluding products falling in category 16Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. except mozzarella.
  • 1.7.5 Processed cheesePermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 1.7.6 Cheese products (excluding products falling in category 16)Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 1.8 Dairy analogues, including beverage whitenersPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 10.2 Processed eggs and egg productsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 11.2 Other sugars and syrupsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 12.1.2 Salt substitutesPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 12.1.2 Salt substitutes — quantum satisPermitted as a member of E 626–635: Ribonucleotides. quantum satis.
  • 12.2.2 Seasonings and condimentsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 12.2.2 Seasonings and condiments — quantum satisPermitted as a member of E 626–635: Ribonucleotides. quantum satis.
  • 12.3 Vinegars and diluted acetic acid (diluted with water to 4-30 % by volume)Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 12.4 MustardPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 12.5 Soups and brothsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 12.6 SaucesPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 12.7 Salads and savoury based sandwich spreadsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 12.8 Yeast and yeast productsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 12.9 Protein products, excluding products covered in category 1.8Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 13.2 Dietary foods for special medical purposes defined in Directive 1999/21/EC (excluding products from food category 13.1.5)Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 13.3 Dietary foods for weight control diets intended to replace total daily food intake or an individual meal (the whole or part of the total daily diet)Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 13.4 Foods suitable for people intolerant to gluten as defined by Commission Regulation (EC) No 41/2009Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. including dry pasta.
  • 14.1.2 Fruit juices as defined by Directive 2001/112/EC and vegetable juicesPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. only vegetable juices.
  • 14.1.3 Fruit nectars as defined by Directive 2001/112/EC and vegetable nectars and similar productsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. only vegetable nectars, E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.1.4 Flavoured drinksPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. E 420, E 421, E 953, E 965, E 966 and E 967 may not be used E 968 may not be used except where specifically provided for in this food category.
  • 14.1.5.2 OtherPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. excluding unflavoured leaf tea; including flavoured instant coffee; E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used in drinks.
  • 14.2.3 Cider and perryPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.4 Fruit wine and made winePermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.5 MeadPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.6 Spirit drinks as defined in Regulation (EC) No 110/2008Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. except whisky or whiskey; E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used except in liqueurs.
  • 14.2.7.1 Aromatised winesPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.7.2 Aromatised wine-based drinksPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.7.3 Aromatised wine-product cocktailsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 14.2.8 Other alcoholic drinks including mixtures of alcoholic drinks with non-alcoholic drinks and spirits with less than 15 % of alcoholPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. E 420, E421, E 953, E965, E 966, E 967 and E 968 may not be used.
  • 15.1 Potato-, cereal-, flour- or starch-based snacksPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 15.2 Processed nutsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 16 Desserts excluding products covered in categories 1, 3 and 4Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 17.1 Food supplements supplied in a solid form, excluding food supplements for infants and young childrenPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. E 410, E 412, E 415, E 417 and E 425 may not be used to produce dehydrated food supplements intended to rehydrate on ingestion.
  • 17.2 Food supplements supplied in a liquid form, excluding food supplements for infants and young childrenPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 18 Processed foods not covered by categories 1 to 17, excluding foods for infants and young childrenPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 2.2.2 Other fat and oil emulsions including spreads as defined by Regulation (EC) No 1234/2007 and liquid emulsionsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 2.3 Vegetable oil pan sprayPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 3 Edible icesPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 4.2.1 Dried fruit and vegetablesPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. E 410, E 412, E 415 E 417 may not be used to produce dehydrated foods intended to rehydrate on ingestion.
  • 4.2.2 Fruit and vegetables in vinegar, oil, or brinePermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 4.2.4.1 Fruit and vegetable preparations excluding compotePermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 4.2.5.4 Nut butters and nut spreadsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 4.2.6 Processed potato productsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 5.1 Cocoa and chocolate products as covered by Directive 2000/36/ECPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. only energy-reduced or with no added sugar.
  • 5.2 Other confectionery including breath refreshening microsweetsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. The substances listed under numbers E 400, E 401, E 402, E 403, E 404, E 406, E 407, 407a, E 410, E 412, E 413, E 414, E 415, E 417, E 418, E 425 and E 440 may not be used in jelly mini-cups, defined, for the purpose of this Regulation, as jelly confectionery of a firm consistence, contained in semi rigid mini-cups or mini-capsules, intended to be ingested in a single bite by exerting pressure on the mini-cups or mini-capsule to project the confectionery into the mouth; E 410, E 412, E 415 E 417 may not be used to produce dehydrated foods intended to rehydrate on ingestion. E425 may not be used in jelly confectionery.
  • 5.3 Chewing gumPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 5.4 Decorations, coatings and fillings, except fruit based fillings covered by category 4.2.4Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 6.2.2 StarchesPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 6.3 Breakfast cerealsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 6.4.2 Dry pastaPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. only gluten free and/or pasta intended for hypoproteic diets in accordance with Directive 2009/39/EC.
  • 6.4.4 Potato gnocchiPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. except fresh refrigerated potato gnocchi.
  • 6.4.5 Fillings of stuffed pasta (ravioli and similar)Permitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 6.5 NoodlesPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 6.6 BattersPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 6.7 Pre-cooked or processed cerealsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 7.1 Bread and rollsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. except products in 7.1.1 and 7.1.2.
  • 7.2 Fine bakery waresPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 8.3.1 Non-heat-treated meat productsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 8.3.2 Heat-treated meat productsPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. except foie gras, foie gras entier, blocs de foie gras, Libamáj, libamáj egészben, libamáj tömbben.
  • 8.3.3 Casings and coatings and decorations for meatPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 9.2 Processed fish and fishery products including mollusks and crustaceansPermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid.
  • 9.3 Fish roePermitted as a member of Group I. Maximum level: 500 mg/kg, individually or in combination, expressed as guanylic acid. only processed fish roe.
Assimilated Regulation (EC) No 1333/2008, Annex II (as at 28 June 2024)and 67 further provisionsretrieved 2026-10-18
JapanConsumer Affairs AgencyNo listing matchedThis site imports only Japan’s list of designated additives (Appended Table 1 to the Regulations for Enforcement of the Food Sanitation Act), matched by English name. Existing additives, natural flavouring agents and ordinary foods used as additives are permitted outside that list and are not imported, so an empty row does not show that Japan does not permit the substance.
South KoreaMinistry of Food and Drug SafetyPermitted, with conditions
Designated food additive: Standards and Specifications for Food Additives, Part III, 1. …

Designated food additive: Standards and Specifications for Food Additives, Part III, 1. 일반식품첨가물 (general food additives), 5'-구아닐산 (“5'-Guanylic acid”, the English the Code prints beside it). Main use (주용도) of 5'-구아닐산: 향미증진제. Standard for use (사용기준) of 5'-구아닐산: (1) [to be used under the general standard for use in II. 2. 1), the minimum amount that achieves the technical effect, with no limit set for this additive in particular] “II. 2. 1)의 규정에 따라 사용하여야 한다.” The Korean is the standard as published. There is no official English translation of the current Code (the English version on MFDS’s website is the 2020 edition and has no legal effect); the English in square brackets is this site’s description of what each sentence does, not a translation of the foods or the levels. Compositional specifications (Part IV) are not imported, nor are the general standards in Part II, which apply to every additive.

Standards and Specifications for Food Additives (식품첨가물의 기준 및 규격), MFDS Notification, Part III (Standards for use, by item)retrieved 2026-10-18
United StatesFood and Drug AdministrationNot listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited.
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

1 food category

no numerical limit (good manufacturing practice)

CXS 192-1995 Table Three, INS 626and 1 further provisionretrieved 2026-09-07

How much is permitted

A listing usually limits the quantity as well as the food. Only one of the forms that takes is a figure: quantum satis and good manufacturing practice permit the amount the technological effect requires and no more, which is a limit rather than the absence of one. Figures below are the range across every food category this page is listed in, and categories differ between regulators — see how much is permitted.

European Union—46 several limits, 2 quantum satis, 22 no quantity stated
Great Britain—2 quantum satis, 66 no quantity stated
South Korea—1 no quantity stated
Codex Alimentarius—2 GMP

No regulator sets a figure for Guanylic acid, 5'-. That is not an absence of control: where the listing says quantum satis or good manufacturing practice, the quantity is limited to what the effect requires.

What it is made from

Produced by bacterial fermentation or by hydrolysing yeast RNA. It occurs naturally in dried mushrooms.

  • Vegan status depends on the source
  • Vegetarian status depends on the source
  • May raise a halal question
  • May raise a kosher question

This is not an omission. What this additive is made from is not fixed — depending on the manufacturer it may be plant, animal or microbial in origin, nobody is required to say which, and the same product can change source between production runs. Ask the manufacturer if it matters to you; a label cannot answer it.

Compare other additives on the dietary indexes.

The two specifications, compared

The European Union sets identity and purity by regulation; JECFA publishes its own through FAO, advisory until a country adopts it. Both documents are below in full. These are the parameters each puts a number on.

ParameterEuropean UnionJECFA
Assayno less than 97 %—
Loss on dryingno more than 1.5 %no more than 1.5 %
Leadno more than 1 mg/kg—

The two documents state the same figures for every parameter compared here.

How the EU defines it

The legal specification an additive must meet to be sold as this E number in the EU — what it is, how it may be made, and the purity it must reach. From Commission Regulation (EU) No 231/2012.

E 626 Guanylic acid

Synonyms: 5'-Guanylic acid

Assay, identification and purity criteria

Description and assay

Einecs
201-598-8
Chemical name
Guanosine-5'-monophosphoric acid
Chemical formula
C₁₀H₁₄N₅O₈P
Molecular weight
363,22
Assay
Content not less than 97,0 % on the anhydrous basis
Solubility
Slightly soluble in water, practically insoluble in ethanol
Description
Odourless, colourless or white crystals or white crystalline powder

Identification

Test for ribose
Passes test
Test for organic phosphate
Passes test
pH
Between 1,5 and 2,5 (0,25 % solution)
Spectrometry
Maximum absorption of a 20 mg/l solution in 0,01N HCl at 256 nm

Purity criteria

Loss on drying
Not more than 1,5 % (120 °C, 4 hours)
Other nucleotides
Not detectable by thin-layer chromatography
Lead
Not more than 1 mg/kg

Commission Regulation (EU) No 231/2012, Annex, E 626

How JECFA defines it

The international specification for identity and purity, prepared by the Joint FAO/WHO Expert Committee on Food Additives and published by FAO. It is a different document from any above, written by a different body and revised on its own cycle; it is advisory, and a country adopts it or does not.

INS 626 5-Guanylic Acid

Synonyms: Guanylic acid, GMP, INS No. 626 GMP; Guanylic acid

Assay, identification and purity criteria

Description and assay

Specification history
5'-GUANYLIC ACID Prepared at the 29th JECFA (1985), published in FNP 34 (1986) and in FNP 52 (1992). Metals and arsenic specifications revised at the 57th JECFA (2001). A group ADI 'not specified' for 5’guanylic acid and its Ca & Na salts was established at the 18th JECFA (1974)
DEFINITION Chemical names
Guanosine-5'-monophosphoric acid
C.A.S. number Chemical formula Structural formula
85-32-5 C 10 H 14 N 5 O 8 P
Formula weight Assay
363.22 Not less than 97.0% and not more than 102.0% of on the dried basis
DESCRIPTION FUNCTIONAL USES Solubility (Vol. 4) Spectrophotometry (Vol. 4)
Odourless, colourless or white crystals, or a white crystalline powder Flavour enhancer Slightly soluble in water; practically insoluble in ethanol A 1 in 50,000 solution of the sample in 0.01 N hydrochloric acid exhibits an absorbance maximum at 256±2nm. The ratio A250/A260 is between 0.95 and 1.03, and the ratio A280/260 is between 0.63 and 0.71.
METHOD OF ASSAY
Weigh accurately about 0.5 g of the sample, dissolve in and make to 1,000 ml with 0.01 N hydrochloric acid. Take 10 ml of this solution and dilute with 0.01 N hydrochloric acid to 250 ml. Determine the absorbance A of the solution in a 1-cm cell at the wave length of 260 nm using 0.01 N hydrochloric acid as the reference. Calculate the content of C 10 H 14 N 5 O 8 P, in % in the sample by the formula:

Identification

Test for ribose (Vol. 4) Test for organic phosphate (Vol. 4)
Passes test Passes test Test 5 ml of a 1 in 400 soln

Purity criteria

Loss on drying (Vol. 4)
Not more than 1.5% (120 o , 4 h)
pH (Vol. 4) Related foreign substances (Vol. 4) Lead (Vol. 4)
1.5 - 2.5 (1 in 400 soln) Chromatographically not detectable Test 2 μl of a 1 in 400 soln Not more than 1 mg/kg Determine using an atomic absorption technique appropriate to the specified level. The selection of sample size and method of sample preparation may be based on the principles of the method described in Volume 4, “Instrumental Methods.”

FAO JECFA Monograph 1 (2006)

Every name it appears under

25 recorded names. A label may use any of them.

E number

  • E626

INS number

  • 626

As it appears in regulation

  • Guanylic acid

Other names

  • GUANYLIC ACID, 5'-

Hazard reference values

Values set by assessing bodies. A body that has not set a value is not listed here.
TypeValuePopulationAssessed byOpinion
ADInot specified—JECFA1985

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated rather than machine-read, and none has been written for this substance yet.

Common questions

Assembled from what is above, in the words the questions are usually asked in. Each answer is the same statement the relevant section makes, with the same citations behind it.

What is E 626?
E 626 is Guanylic acid, 5'-. Guanylic acid is a savoury flavour enhancer, the mushroom counterpart to inosinate. Dried shiitake are rich in it, which is why drying mushrooms makes them taste more intensely of themselves than fresh ones do.
What is Guanylic acid, 5'- used for in food?
It is listed as a flavour enhancer — the role Codex assigns it. This page shows every function each regulator records, with the citation for each.
Where is Guanylic acid, 5'- permitted?
Of the seven regulators this site reads, the EU, Great Britain, South Korea and the Codex standard permit it. Each permission is for named foods at named levels, not a blanket one; the table on this page gives them with citations.
Is Guanylic acid, 5'- vegan?
It depends on the source, and a label will not tell you. Guanylic acid, 5'- can be made from plant or animal material, manufacturers are not obliged to say which, and the same product can change between production runs. Anyone who needs to know has to ask the manufacturer.

Sources for this page

  • eu retrieved 2026-10-18
  • gb retrieved 2026-10-18
  • kr retrieved 2026-10-18
  • gsfa retrieved 2026-09-07
  • euspecs retrieved 2026-10-18
  • jecfaspecs retrieved 2026-09-23

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable: a JSON record of this additive is given on request —how to ask for access.

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