Foods Containing E337 (Sodium Potassium Tartrate)
E337 (Sodium Potassium Tartrate) is a mixed salt of tartaric acid, used as a antioxidant to help stop fats and oils turning rancid and protect food colour and flavour. Here's where you're most likely to find it on food labels.
Common foods that contain E337
E337 is used across oils, margarine, snacks, cured meats, soft drinks and processed foods. The foods where it appears most often include:
- Oils
- Margarine
- Snacks
- Cured meats
- Soft drinks and processed foods
Exact usage varies by brand and recipe — the only way to know for certain whether a specific product contains E337 is to check its ingredients list, where it must be declared by law, either as "E337" or as "Sodium Potassium Tartrate".
How to spot E337 on a label
In the UK and EU, additives must appear in the ingredients list with their function and either their E-number or full name — for example "antioxidants: E337" or "antioxidants: sodium potassium tartrate". In the US the E-number system isn't used, so look for the full name "Sodium Potassium Tartrate" instead.
Should you avoid foods containing E337?
E337 is considered safe. It is authorised across the EU, UK and US, and safety evaluations by the European Food Safety Authority (EFSA) have not identified health concerns at the levels used in food. For most people there is no reason to avoid E337.
Full guide to E337: safety, vegan and halal status →
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Additive data sourced from Open Food Facts (ODbL licence) and the European Food Safety Authority (EFSA).