Last reviewed: 8 May 2026
The vitamin C salt that blocks nitrosamine formation in cured meat and strengthens UK pre-packed bread.
E301 is sodium ascorbate, the sodium salt of L-ascorbic acid. Chemical formula C6H7NaO6. It is a white-to-yellowish crystalline powder that dissolves readily in water.
Once it is in your body, sodium ascorbate behaves chemically the same way ascorbic acid does. Your gut absorbs it identically, and it counts towards the same vitamin C activity. So when you see "E301" on a UK label, you are reading a form of vitamin C, not a synthetic substitute or a "vitamin-C-like" compound.
The difference between E301 and its parent acid E300 is the salt. Bonding ascorbic acid to sodium gives a near-neutral pH (roughly 7.4 in solution), whereas free ascorbic acid sits around pH 2.5 — sharp and acidic. Both forms reach the bloodstream as vitamin C; the chemistry only matters inside the food, before you eat it.
E301 is produced industrially from glucose via fermentation. There is no animal source involved at any stage, which makes it suitable for vegan and vegetarian formulations. It is the same starting chemistry the rest of the vitamin C family (E300, E302, E303, E304) is built from.
The pH-neutral form is the whole point. Plain ascorbic acid (E300) is a useful antioxidant, but it acidifies whatever it is added to. In a fizzy drink that is fine — the drink is already acidic. In cured meat, in a bread dough, in a milk-based product or in a delicate fruit prep, dropping the pH would change taste, destabilise emulsions or interfere with other ingredients (gelling agents, dairy proteins, leavening systems).
E301 lets a manufacturer get the antioxidant action of vitamin C — preventing oxidation, mopping up free radicals, blocking certain reactive intermediates — without shifting the food's acidity. That single property is why sodium ascorbate, rather than ascorbic acid, dominates two specific UK food categories: cured meat and pre-packed sliced bread. In both, an acidic environment would cause problems; a neutral antioxidant solves them cleanly.
Sodium ascorbate also has slightly better stability than ascorbic acid in some applications — it is less reactive with metal ions and tolerates dough mixing and meat curing temperatures without degrading as quickly.
This is the single most important reason E301 appears on UK food labels, and the one most shoppers don't know about.
Cured meats — bacon, ham, gammon, sausages, frankfurters, salami — are preserved using nitrites (E250 sodium nitrite) and/or nitrates (E251 sodium nitrate, see our E251 guide for the cancer-risk context). The cure fixes the meat's pink colour, develops cured flavour and inhibits Clostridium botulinum. The trade-off is that when nitrite-cured or nitrate-cured meat is heated to high temperatures — frying bacon in a pan, grilling sausages, roasting gammon — nitrites can react with secondary amines naturally present in the meat to form N-nitroso compounds (nitrosamines). These are the carcinogens behind the IARC's 2015 classification of processed meat as Group 1 — known to cause cancer in humans, with the strongest evidence for bowel cancer.
Ascorbate — vitamin C in either the E300 or E301 form — interrupts this reaction. It chemically reduces nitrite back to nitric oxide before the nitrite has a chance to react with the amines, so the carcinogenic N-nitroso compound never forms in the first place. The reaction is fast, well-characterised and dose-dependent: more ascorbate, fewer nitrosamines.
This is why modern UK supermarket bacon, ham, sausages and cured-meat products routinely list E301 (or E300, or E316 sodium erythorbate) alongside E250 and E251 in the ingredients. EU and UK food regulations recognise the protective role of ascorbate in cured meats; member states' food safety bodies have long encouraged or required its addition to nitrite-cured meat formulations as a nitrosamine-mitigation step.
Practical takeaway for shoppers: if you scan a UK ham or bacon pack and see E301 listed alongside E250 or E251, it is evidence the manufacturer is using ascorbate to limit nitrosamine formation during cooking. It does not undo the IARC Group 1 classification of processed meat — the risk of bowel cancer at the population level is well established and the NHS still caps adult processed-meat intake at 70 g per day. But on a label, E301 next to E250 is a chemistry detail worth understanding rather than another e-number to worry about.
The second major UK use is in pre-packed sliced bread. Walk down the bread aisle in any UK supermarket — Hovis, Warburtons, Kingsmill, Allinson's, supermarket own-label loaves — and a large fraction of the ingredient lists feature either E300 (ascorbic acid) or E301 (sodium ascorbate) as a flour-treatment agent.
The chemistry: when ascorbate is added to a dough and the dough is mixed and oxygenated, the ascorbate oxidises rapidly to dehydroascorbic acid. Dehydroascorbic acid promotes the formation of disulphide cross-links between gluten proteins. The result is a stronger, more elastic gluten network, which holds gas better during proving. That means a taller loaf, a finer crumb structure, more uniform slices and longer shelf life — exactly what high-throughput pre-packed bread production needs.
Levels in flour are tiny: typically 30–80 parts per million of flour weight. By the time the loaf is baked, almost all of the ascorbate has been consumed in the dough chemistry, and any residual vitamin C activity is largely destroyed by oven heat. So the consumer-facing vitamin C contribution from a bread improver is minor — the additive is doing its job long before the bread reaches your plate.
Artisan, sourdough and longer-fermentation breads generally don't need an ascorbate improver — slow fermentation does the gluten development naturally. It is industrial fast-bake bread (the Chorleywood Process and its descendants) where ascorbate has become standard.
If you compare ingredient lists across products, you will see five related e-numbers — all forms of vitamin C, each with a slightly different role:
For the body, all five contribute to vitamin C status. For the formulator, the choice depends on what the food matrix needs: pH, solubility, sodium load, mineral content.
EFSA (European Food Safety Authority) classifies E301 as having an Acceptable Daily Intake of "not specified" — also expressed as quantum satis, "as much as is technologically necessary". In practice this means there is no numerical mg/kg/day cap; manufacturers add the amount the food technology requires, and no more. EFSA's most recent re-evaluation (2015) of the ascorbate family confirmed there is no toxicological concern from typical food-additive use levels.
In the United States, sodium ascorbate is classified as Generally Recognized as Safe (GRAS) by the FDA, with the same use-level-determined-by-need approach.
Under UK and retained EU food labelling rules, E301 must appear in the ingredients list either as "sodium ascorbate" or as "E301" (or both), in descending order of weight. Where it is performing a specific technological function — antioxidant, flour treatment agent, vitamin — that category may also be declared.
Although E301 is chemically a form of vitamin C, the amounts used as a food additive are small relative to typical UK intake. Rough order-of-magnitude figures:
For context, the NHS Reference Nutrient Intake (RNI) for vitamin C is 40 mg per day for UK adults. So additive use makes a measurable but generally minor contribution outside of fortified drinks. The big dietary sources of vitamin C remain fresh fruit and vegetables — peppers, citrus, kiwi, strawberries, broccoli, potatoes — not the residual ascorbate in cured meat or bread.
E301 is suitable for vegan and vegetarian diets. Industrial production starts from glucose and uses bacterial or yeast fermentation; there is no animal-derived input in the additive itself. The carrier products it ends up in — cured meats, dairy, fortified foods — may not be vegan, but the additive is.
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