E304 - Fatty acid esters of ascorbic acid

At a glance

• What it is: A group of fat‑soluble antioxidants made by attaching vitamin C (ascorbic acid) to fatty acids.
• What it does: Helps prevent oxidation in fats and oils, stabilizes flavors and colors, and protects sensitive vitamins.
• Where it’s used: Fats and oils, margarines and spreads, fried snacks, baked goods, and some fortified foods.
• Label names: E304, ascorbyl palmitate, ascorbyl stearate.
• Regulatory status: Permitted in the European Union as E304 and recognized as Generally Recognized as Safe (GRAS) in the United States.

Why is Fatty acid esters of ascorbic acid added to food?

These additives slow down oxidation, the chemical reaction that makes fats taste stale and smell rancid. In simple terms, they “catch” reactive oxygen that would otherwise break down oils, colors, and aromas in foods, so products stay fresh longer.¹ Because they are fat‑soluble, they work well in oily parts of foods and can complement mixed antioxidant systems, often alongside tocopherols (vitamin E).¹

What foods contain Fatty acid esters of ascorbic acid?

You’re most likely to find E304 in foods that contain fats or oils, including:

• Vegetable oils and frying oils
• Margarines and spreads
• Fried snacks and chips
• Biscuits, crackers, and other baked goods
• Dressings, sauces, and powdered mixes with fat
• Fortified foods to help protect sensitive vitamins

The most common label names are “ascorbyl palmitate” and “ascorbyl stearate,” sometimes followed by “E304.”¹

What can replace Fatty acid esters of ascorbic acid?

Food makers can use other antioxidants or stabilizers, depending on the recipe:

• Natural mixed tocopherols such as tocopherol-rich extract or single forms like alpha-tocopherol
• Synthetic antioxidants such as BHA or BHT
• Propyl gallate or other gallates
• Extracts of rosemary
• Synergists like citric acid or sodium citrates, which can help antioxidants work better in some systems

How is Fatty acid esters of ascorbic acid made?

E304 additives are made by reacting ascorbic acid (vitamin C) with long‑chain fatty acids, typically palmitic acid or stearic acid. The result is an “ester,” which is more oil‑soluble than plain ascorbic acid, making it useful in fat‑rich foods.² In the European Union, official specifications cover identity, purity, and how the additives should be produced and tested.²

Is Fatty acid esters of ascorbic acid safe to eat?

Regulators in the European Union have evaluated E304 and concluded there is no safety concern at the reported uses and use levels in food.¹ In the United States, ascorbyl palmitate and ascorbyl stearate are listed among substances Generally Recognized as Safe (GRAS) when used in accordance with good manufacturing practice.³

These esters are broken down in the body to ascorbic acid and the corresponding fatty acids, which are normal dietary components.⁴

Does Fatty acid esters of ascorbic acid have any benefits?

For consumers, the main benefit is better quality and shelf life. E304 helps keep oils from turning rancid, supports stable flavors and colors, and can help protect sensitive vitamins like A and E during storage.¹ While it is derived from vitamin C, it is added as an antioxidant, not as a primary source of vitamin C in the diet.

Who should avoid Fatty acid esters of ascorbic acid?

• People who prefer vegetarian or vegan products should check with the manufacturer. The fatty acids can be sourced from plants (such as palm or other vegetable oils) or animals, depending on the supplier.
• Anyone with a known sensitivity to ascorbate ingredients should follow their healthcare provider’s advice.

Myths & facts

• Myth: “E304 is the same as taking vitamin C.”
  Fact: It is used as an antioxidant in fats and oils; any vitamin C contribution is incidental and small compared to foods or supplements.
• Myth: “E304 is a trans fat.”
  Fact: It is not a trans fat; it is an antioxidant made from vitamin C and common fatty acids.
• Myth: “All synthetic antioxidants are unsafe.”
  Fact: E304 has been evaluated by EU and U.S. authorities and is permitted for use within set conditions.¹³

Fatty acid esters of ascorbic acid in branded foods

On ingredient lists, look for “ascorbyl palmitate,” “ascorbyl stearate,” or “E304.” You’ll most often see it in products with noticeable fat content, such as oils, spreads, fried snacks, and baked goods. It may also appear alongside other antioxidants like tocopherols, BHA, BHT, or propyl gallate.

References

Footnotes

1. Re-evaluation of ascorbyl palmitate (E 304(i)) and ascorbyl stearate (E 304(ii)) as food additives — EFSA Journal. https://www.efsa.europa.eu/en/efsajournal/pub/4085 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

2. Commission Regulation (EU) No 231/2012: Specifications for food additives (includes E 304 ascorbyl palmitate and ascorbyl stearate) — EUR-Lex. https://eur-lex.europa.eu/eli/reg/2012/231/oj ↩ ↩²

3. Substances Generally Recognized as Safe, Subpart B—Multipurpose food substances (includes ascorbyl palmitate and ascorbyl stearate) — U.S. FDA eCFR. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-182/subpart-B ↩ ↩²

4. Ascorbyl palmitate and ascorbyl stearate: JECFA evaluation (metabolism and safety) — WHO/FAO. http://www.inchem.org/documents/jecfa/jecmono/v35je03.htm ↩