E106 - flavin mononucleotide

At a glance

• What it is: a phosphorylated form of vitamin B2 (riboflavin) used as a food color and nutrient.
• What it does: adds a yellow to yellow‑orange hue; more water‑soluble than plain riboflavin.
• Typical foods: beverages, dairy desserts, baked goods, confectionery, sauces, and fortified products.
• Common stand‑ins: riboflavin, curcumin, annatto, beta‑carotene, and caramel.
• Safety: permitted by major regulators and re‑evaluated with no safety concern at reported uses when used as a coloring food additive.¹ In the U.S., riboflavins (including the phosphate form) are permitted color additives.²³
• Label clues: flavin mononucleotide, riboflavin‑5′‑phosphate, FMN, or vitamin B2.

Why is flavin mononucleotide added to food?

Manufacturers use FMN to produce a warm yellow color and, at times, to contribute vitamin B2. Compared with plain riboflavin, FMN dissolves better in water and holds up well in acidic foods and drinks, which is why it is favored in beverages and other water‑based products.¹

What foods contain flavin mononucleotide?

You’re most likely to see FMN in:

• Soft drinks and energy or sports beverages
• Dairy desserts and flavored milks
• Baked goods, breakfast cereals, and dry mixes
• Candies, chewing gum, and dessert toppings
• Sauces, soups, and instant noodles

On ingredient lists it may appear as “flavin mononucleotide,” “riboflavin‑5′‑phosphate,” “FMN,” or simply as a form of vitamin B2.

What can replace flavin mononucleotide?

Alternatives depend on the product:

• For a similar yellow tone in water‑based foods: riboflavin or curcumin
• For orange‑yellow shades: beta‑carotene or annatto
• For brownish tones: caramel

Color choice also depends on solubility, light stability, pH, and label goals.

How is flavin mononucleotide made?

FMN is produced by attaching one phosphate group to riboflavin (vitamin B2), creating the mononucleotide phosphate of riboflavin.⁴ The result is a bright yellow, water‑soluble powder suitable for use in foods and beverages.

Is flavin mononucleotide safe to eat?

Regulators in the European Union have re‑evaluated riboflavins used as food colors and found no safety concern at the reported uses and exposure levels.¹ In the United States, the Food and Drug Administration (FDA) permits riboflavin and riboflavin‑5′‑phosphate as color additives exempt from certification for use in foods, following good manufacturing practice.²³

Does flavin mononucleotide have any benefits?

FMN is a biologically active form of vitamin B2. In the body, riboflavin is converted to FMN and FAD (flavin adenine dinucleotide), coenzymes that help enzymes release energy from carbohydrates, fats, and proteins.⁵ At the small amounts used just for coloring, FMN adds little nutrition, but in fortified foods it can contribute to your daily vitamin B2 intake. Riboflavin can turn urine a bright yellow color; this effect is harmless.⁵

Who should avoid flavin mononucleotide?

There is no specific group in the general population that needs to avoid FMN when it is used within food regulations. If your clinician has advised you to limit vitamin B2 or phosphorus for medical reasons, discuss ingredient choices with them.

Myths & facts

• Myth: FMN is a synthetic dye unrelated to nutrients. Fact: FMN is a vitamin B2 derivative used both as a color and a nutrient.
• Myth: It always adds a lot of vitamin B2. Fact: Coloring‑level amounts are small; only fortified foods add meaningful vitamin B2.
• Myth: It’s unstable in drinks. Fact: FMN is more water‑soluble than riboflavin and performs well in acidic beverages.¹

flavin mononucleotide in branded foods

You can spot FMN on labels of:

• Energy and sports drinks
• Flavored milks and dairy desserts
• Breakfast cereals and mixes
• Candies and gum

Look for “flavin mononucleotide,” “riboflavin‑5′‑phosphate,” “FMN,” or vitamin B2 in the ingredient list.

References

Footnotes

1. Re‑evaluation of riboflavins (E 101) as food additives — European Food Safety Authority (EFSA). https://www.efsa.europa.eu/en/efsajournal/pub/3145 ↩ ↩² ↩³ ↩⁴

2. Color Additive Status List — U.S. Food & Drug Administration. https://www.fda.gov/industry/color-additive-inventories/color-additive-status-list ↩ ↩²

3. 21 CFR 73.450 Riboflavin — Electronic Code of Federal Regulations (eCFR). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-A/part-73/subpart-A/section-73.450 ↩ ↩²

4. Flavin mononucleotide (FMN) — PubChem, National Institutes of Health. https://pubchem.ncbi.nlm.nih.gov/compound/Flavin-mononucleotide ↩

5. Riboflavin Fact Sheet for Health Professionals — NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/ ↩ ↩²