Disodium Guanylate: Uses, Nutrition, and Safety

Typically made from dried, disodium guanylate is a type of salt that is derived from guanosine monophosphate (GMP).

Disodium guanylate is made through the fermentation of a variety of vegetables, most often tapioca starch or seaweed. It can be listed on a food label as "natural flavors," making it difficult to tell if a product contains this additive.

Disodium guanylate can be used alone, although it's less common because it's more expensive to make than MSG or other glutamates. Disodium glutamate increases the flavor intensity of salt, requiring less salt to achieve the same result.

Foods such as tomatoes and cheese contain glutamates, which are naturally occurring amino acids that can be found in the brain, where they function as neurotransmitters. Glutamates can improve how your tongue perceives salt. 

Disodium guanylate and MSG work together to improve food flavor. In fact, humans react to MSG-nucleotide combinations like GMP 8 times more powerfully than they do to MSG alone. In other words, you're likely to think that food tastes better when MSG and disodium guanylate are combined in a food. The combination produces an umami flavor, which is a savory or meaty flavor found in beef, mushrooms, yeast, and rich broths. Disodium guanylate requires the addition of MSG because it does not produce umami on its own.

When mixed with disodium inosinate, disodium guanylate can be used in foods as a substitute for monosodium glutamate. I+G or disodium 5′-ribonucleotides is the name of the mixture.

Maximum concentrations (as guanylic acid) range from 500 mg/kg to not specified in the following foods:

• Dairy products 
• Fats and oils 
• Edible ices 
• Fruit and vegetables 
• Confectionery 
• Cereals
• Baked goods
• Meat 
• Fish and fish products 
• Eggs and egg products 
• Sugars, syrups, honey, and table sweeteners 
• Salts, spices, soups, sauces, salads, and protein products 
• Beverages
• Seasonings and condiments

The use of disodium guanylate as a food additive has been approved by the FDA, European Food Safety Authority (EFSA), Joint FAO/WHO Expert Committee on Food Additives (JECFA), and other authorities.

• FDA: Disodium guanylate, according to the FDA, is an additive that can be used in foods without harm to enhance flavor.
• EFSA: According to Commission Regulation (EU) No 231/2012, disodium guanylate (E627) is a permitted food additive that falls under the category of "additives other than colors and sweeteners."

Many people wonder whether disodium guanylate is harmful to their health. Almost no negative effects have been observed, and it is widely regarded as safe. 

According to a JECFA study from 1993, there were no reported cases of short- or long-term toxicity, carcinogenicity, teratogenicity, genotoxicity, or harmful effects on reproduction. However, in the absence of long-term toxicity reports, it is best to exercise caution when consuming foods containing additives.