E640I - Glycine

At a glance

Here are the quick facts about glycine.

• What it is: An amino acid and flavor enhancer with E-number E640i
• What it does: Rounds umami and salty flavors; helps mask bitterness
• Where it’s used: Savory snacks, soups, sauces, meat products, beverages, and meal replacements
• Taste: Mildly sweet, clean tasting
• How it’s made: Typically by chemical synthesis or fermentation, then refined to food-grade purity
• Safety: Authorized as a food additive in the European Union when used as intended

Why is Glycine added to food?

Food makers add glycine to boost and balance flavor. It can smooth harsh edges, make saltiness taste more rounded, and add body to savory (umami) profiles. In the European Union, glycine (E 640 i) is authorized as a flavor enhancer in the food additive system, which means it may be used to improve taste rather than to sweeten or preserve the product.¹

What foods contain Glycine?

You can find glycine in many everyday foods, especially where a rounded savory taste is wanted:

• Instant soups, bouillon, and noodle seasonings
• Sauces and condiments (soy-based sauces, barbecue sauces, marinades)
• Meat and plant-based meat products
• Savory snacks and spice mixes
• Protein drinks, meal replacements, and nutrition bars
• Some beverages to soften acidity or bitterness

On labels, look for “glycine,” “E640,” or “E640i.”

What can replace Glycine?

Other flavor enhancers can play a similar role, depending on the recipe:

• Monosodium glutamate (MSG) for strong umami lift
• Disodium inosinate or disodium guanylate, or blends like disodium 5'-ribonucleotide for synergistic savory notes
• Yeast extracts or hydrolyzed vegetable proteins for broader savory impact
• If sodium is a concern, some products use glycine and its sodium salt carefully, or avoid the sodium salt entirely

Choice depends on flavor target, cost, labeling, and dietary limits.

How is Glycine made?

Commercial glycine is most often produced by chemical synthesis (for example, starting from chloroacetic acid and ammonia), or by fermentation routes. After production, it is purified and tested to meet food-grade standards. In the EU, food-grade glycine must meet identity and purity criteria set out in Commission Regulation (EU) No 231/2012 for E 640.¹

Is Glycine safe to eat?

Glycine (E 640 i) and its sodium salt are on the EU Union list of permitted food additives, meaning they are legally approved for use in foods under the conditions laid down in EU law.² Glycine is also a naturally occurring amino acid in the human body and in many foods.³ As with all additives, manufacturers are expected to use only as much as needed to achieve the intended effect.

Does Glycine have any benefits?

• Culinary: It rounds and stabilizes flavor, helping recipes taste smoother and less harsh.
• Nutrition: It contributes small amounts of the amino acid glycine. However, typical additive levels are low compared with protein from regular foods.
• Formulation: It can help reduce the need for high salt or sugar in some recipes by improving overall flavor balance.

Who should avoid Glycine?

• People advised by a clinician to limit specific amino acids (for example, due to rare metabolic disorders) should review labels and consult their care team.
• Those on strict low-sodium diets might prefer products that use glycine (E640i) rather than the sodium salt variant sodium glycinate, depending on the overall recipe.
• If you have any sensitivity you suspect is linked to a particular product, discuss it with a healthcare professional.

Myths & facts

• Myth: Glycine is the same as MSG. Fact: Glycine is a different amino acid and works more gently; MSG is monosodium glutamate, which gives a strong umami boost.
• Myth: Glycine is just an artificial chemical. Fact: Glycine occurs naturally in foods and the human body; the food-additive form is purified to consistent food-grade standards.
• Myth: Glycine is a sweetener. Fact: It tastes mildly sweet, but it is used as a flavor enhancer, not as a sugar substitute.

Glycine in branded foods

On ingredient lists, look for:

• “Glycine,” “E640,” or “E640i”
• Sometimes paired with other flavor enhancers such as monosodium glutamate or disodium 5'-ribonucleotide You’ll most often see it in savory seasonings, instant soups, sauces, meat products, and some nutrition beverages.

References

Footnotes

1. Commission Regulation (EU) No 231/2012 — Specifications for food additives listed in Annexes II and III to Regulation (EC) No 1333/2008. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32012R0231 ↩ ↩²

2. Regulation (EC) No 1333/2008 on food additives — Union list framework and conditions of use. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32008R1333 ↩

3. Glycine — PubChem (NIH). https://pubchem.ncbi.nlm.nih.gov/compound/Glycine ↩