Potassium malate
The potassium salt of malic acid, a naturally occurring fruit acid. Used to control acidity and keep flavours stable in processed foods.
What is it?
Potassium malate is the potassium salt of malic acid, the organic acid that gives apples and other fruits their tart taste. It is produced commercially by neutralising malic acid with potassium carbonate or potassium hydroxide. The result is a white, water-soluble powder.
What does it do?
Acts as an acidity regulator: it buffers the pH of a food product, keeping it within a target range so that flavour, texture and colour remain consistent during processing and shelf life. It can also act as a mild flavour enhancer, contributing a clean tartness similar to the effect of apple juice in a recipe.
Where you will see it
Found in fruit-flavoured beverages, still and sparkling soft drinks, fruit preserves and jams, confectionery, baked goods, canned and bottled fruit products, soups and sauces, and sports drinks. On a UK label it will appear as 'potassium malate' or 'E351'.
What the science says
Malic acid and its salts in the body
Malic acid is a normal intermediate in human metabolism, produced and consumed continuously in the citric acid cycle (the body's main energy pathway). The potassium salt dissociates in the gut into malic acid and potassium ions, both of which are handled by normal metabolic routes. No accumulation or novel metabolite is introduced by consuming it as a food additive.
Malic acid and its salts are metabolised via the tricarboxylic acid cycle, the same pathway used to process energy from food. No adverse effects were identified at levels used in food.
Potassium intake from food additives
Potassium malate contributes a small amount of potassium to total dietary intake. For most people this is of no significance. Individuals with chronic kidney disease who must restrict dietary potassium should be aware that potassium-containing additives across multiple processed foods can add up. This is a general dietary management point, not a finding unique to E351.
People with kidney disease who require a low-potassium diet are advised by dietitians to account for all potassium-containing additives, including potassium salts used as acidity regulators, when calculating daily intake.
Where it stands with the regulators
Who should be careful
People with chronic kidney disease who are following a potassium-restricted diet should count potassium from all sources in processed foods, including potassium-containing additives. Look for 'potassium malate' or 'E351' on the label. For everyone else, no specific avoidance is indicated.
The honest read
Potassium malate sits at the least contentious end of the food additive spectrum. It is the potassium salt of malic acid, a compound the body makes and breaks down continuously as part of normal energy metabolism. Regulators in both the UK and EU have not set a numerical daily limit because no intake level tested has produced an adverse effect. The additive science literature has not produced a single credible concern specific to E351 as a food additive. The relevant dietary consideration is the potassium itself, which matters only in the specific clinical context of kidney disease.
Related additives
Common questions
Is E351 banned in the UK?
No. Potassium malate (E351) is on the UK FSA approved-additives list and is permitted across a range of food categories. It is also authorised in the EU under Regulation 1333/2008.
Does E351 contain potassium I should worry about?
For most people the potassium contributed by E351 in food is a minor fraction of total daily intake and presents no issue. If you have been told by a doctor or dietitian to follow a low-potassium diet (typically due to kidney disease), you should factor in potassium from all additives, including E351, when tracking your daily total.
What foods contain E351?
Potassium malate appears in fruit-flavoured soft drinks, sports drinks, fruit preserves, confectionery, baked goods, canned fruit products, and soups and sauces. Check the ingredients list for 'potassium malate' or 'E351'.
Is E351 vegan?
Yes. Potassium malate is produced from malic acid (found in fruit) and a potassium mineral salt. It contains no animal-derived ingredients and is suitable for vegans and vegetarians.
Sources
- Approved additives and E numbers - Food Standards Agency
- EU Regulation 1333/2008 on food additives - EUR-Lex
- Potassium malate - Wikipedia
- NHS guidance on potassium and kidney disease
See this on every food you scan
NutraSafe reads the label and puts every additive into plain English, with the source, right in the app.
Get NutraSafe on the App Store