E300 - Ascorbic acid

At a glance

• Names: E300, L‑ascorbic acid, vitamin C
• What it does: antioxidant and metal‑binding “sequestrant”; helps prevent browning and flavor loss; strengthens bread dough
• Common in: breads and buns, fruit drinks and juices, canned fruits and vegetables, jams and preserves; in cured meats you’ll more often see related salts like sodium ascorbate
• Related additives: sodium ascorbate, calcium ascorbate, ascorbyl palmitate, ascorbyl stearate
• How it’s made: typically from glucose by fermentation and/or chemical steps
• Safety: evaluated by regulators; normal food uses are considered safe

Why is Ascorbic acid added to food?

Ascorbic acid protects foods from oxidation. Oxygen and trace metals can make colors fade and flavors turn “stale”; ascorbic acid slows these reactions by donating electrons and by binding metals (as a sequestrant). In bakery flour it also acts as a dough improver: it is converted to dehydroascorbic acid during mixing, which helps the gluten network form and gives better loaf volume and crumb.¹

What foods contain Ascorbic acid?

You’ll most often find E300 in:

• Breads, rolls, and buns as a flour‑treating agent or dough conditioner (listed as an optional ingredient in the U.S. bread standard of identity).¹
• Fruit juices, nectars, and soft drinks to protect flavor and vitamin content.
• Fresh‑cut and canned fruits and vegetables to limit browning and color loss.
• Jams, jellies, and fruit preparations as an antioxidant.
• Processed meats: the “ascorbate family” is used to speed curing and limit nitrosamine formation. In U.S. bacon, regulations specifically require either sodium ascorbate or sodium erythorbate, which are closely related to E300.²

What can replace Ascorbic acid?

Alternatives depend on the job you need done:

• Antioxidants in fats and oils: tocopherols or alpha‑tocopherol
• Anti‑browning in fruits: citric acid or sulphur dioxide where allowed
• Cure accelerators and color protectors in meats: erythorbic acid or sodium erythorbate
• Lipid‑phase antioxidant in emulsions: ascorbyl palmitate or ascorbyl stearate
• Natural flavor/color protection: extracts of rosemary

How is Ascorbic acid made?

Food‑grade ascorbic acid is produced industrially from glucose. Manufacturers use either the classic Reichstein process (a sequence of hydrogenation and chemical steps) or modern routes that include microbial fermentation followed by purification to meet additive specifications.³

Is Ascorbic acid safe to eat?

Regulators in the European Union re‑evaluated E300 (along with its salts E301 and E302) and found no safety concern at reported use levels; the acceptable daily intake (ADI) was “not specified,” meaning it is of low toxicological concern at typical intakes.³ In the United States, its use is built into standards such as the bread rule and is recognized as safe and suitable in many foods.¹

Does Ascorbic acid have any benefits?

In the body, vitamin C is needed to make collagen, helps regenerate other antioxidants, and supports normal immune function.⁴ The amount added to foods for preservation can contribute to daily vitamin C intake, though levels vary by product.⁴

Who should avoid Ascorbic acid?

Most people can consume E300 without issues. However:

• People with iron overload disorders (such as hemochromatosis) should avoid high supplemental vitamin C because it can increase iron absorption; ask a healthcare professional for advice.⁴
• Those with a history of certain kidney stones may be advised to limit high‑dose vitamin C supplements; this is not usually a concern at normal food additive levels.⁴

Myths & facts

• “Natural” and “synthetic” vitamin C are chemically identical L‑ascorbic acid and work the same in the body.⁴
• Ascorbic acid is vitamin C, not the same thing as citric acid. They taste tart, but they do different jobs.
• It’s an antioxidant, not a preservative that stops all spoilage. Good hygiene and packaging still matter.

Ascorbic acid in branded foods

On labels you might see “ascorbic acid,” “vitamin C,” or “E300.” It commonly appears in:

• Sandwich breads and rolls as a dough conditioner
• Fruit juices, smoothies, and powdered drink mixes to protect flavor or fortify vitamin C
• Canned or jarred fruits and vegetables to help keep color
• Processed meats often list related forms like sodium ascorbate for curing support

Tip: If you are scanning an ingredient list, look near the end—ascorbic acid usually appears at low levels.

References

Footnotes

1. Bread, rolls, and buns — 21 CFR 136.110. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-136/section-136.110 ↩ ↩² ↩³

2. Use of ascorbate/erythorbate in bacon — 9 CFR 424.21. https://www.ecfr.gov/current/title-9/section-424.21 ↩

3. Re‑evaluation of ascorbic acid (E 300), sodium ascorbate (E 301) and calcium ascorbate (E 302) as food additives — EFSA Journal (2015) 13(5):4086. https://www.efsa.europa.eu/en/efsajournal/pub/4086 ↩ ↩²

4. Vitamin C Fact Sheet — NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/ ↩ ↩² ↩³ ↩⁴ ↩⁵