Last reviewed: 11 May 2026
Citrus-derived acidulant used across UK drinks, sweets and processed foods.
E330 is citric acid — naturally present in citrus fruit and produced by your own cells as a step in the Krebs cycle. EFSA and the FDA approve it with no numerical ADI. The one documented dietary issue is dental enamel erosion from frequent acidic drinks.
E330 is citric acid, a weak organic acid naturally present in citrus fruits.
Your body produces citric acid naturally as part of the Krebs cycle (cellular energy production).
Modern method (95% of production): Fermentation of sugar using Aspergillus niger mold
Old method (rare now): Extraction from lemon juice (expensive, wasteful)
Citric acid produced by Aspergillus niger fermentation is chemically identical to the citric acid extracted from lemon juice — same C₆H₈O₇ molecule, indistinguishable in the body. The "from lemons" label is a marketing distinction, not a chemistry one.
Citric acid is a normal intermediate of the Krebs cycle — every cell in the body produces and consumes it continuously as a step in energy metabolism. Ingested citric acid enters that same pathway and is broken down to CO₂ and water. It does not accumulate.
EFSA's 2018 re-evaluation set no numerical ADI for citric acid and its salts (E330, E331, E332, E333), reflecting the absence of identifiable toxicity at dietary doses. The FDA classifies citric acid as Generally Recognized As Safe (GRAS).
The published dental literature is clear that frequent or prolonged contact between teeth and acidic drinks (pH 2.5–3.5) softens and erodes enamel. Citric acid is among the more erosive food acids in laboratory comparison; orange and lemon sodas, sports drinks, energy drinks and lemon water sipped throughout the day all contribute. Solid foods containing citric acid don't produce the same effect because chewing stimulates saliva, which buffers the acid quickly.
Practical mitigations the British Dental Association recommends:
The published toxicology does not link dietary citric acid to gut, kidney or metabolic problems. Some clinical work suggests dietary citrate may modestly reduce calcium-stone formation in stone-formers — the opposite direction to a harm signal. Allergic reactions to dietary citric acid are rare in the case literature; where reported, they're sometimes traced to mould-residue impurities from the fermentation process rather than the molecule itself.
Often confused — they're different molecules and do different jobs.
| Aspect | Citric Acid (E330) | Vitamin C (E300) |
|---|---|---|
| Chemical formula | C₆H₈O₇ | C₆H₈O₆ |
| Nutritional value | None — it's an acid, not a nutrient | Essential vitamin (UK NRV 80mg/day) |
| Function in food | Acidulant, preservative, flavour | Antioxidant, nutrient |
| In a lemon | 6–8% by weight | ~50mg per 100g |
UK / EU: approved with no numerical ADI (EFSA 2018).
US: FDA classifies citric acid as Generally Recognized As Safe (GRAS).
Organic foods: permitted in organic products under retained UK organic regulations.
Look for "E330", "citric acid", or "acidity regulator" in the ingredient list. It's one of the most common additives in UK soft drinks, sweets, fruit preparations and ready meals.
Scan UK barcodes to see how often citric acid and other acidulants appear in your weekly shop.
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