Acidity Regulators

Acids

Acetic acid (E260)

Acetic acid (E260) is derived from vinegar which is essentially a solution of 5-10% acetic acid in water. Many types of vinegar are available from the oxidation of different sources of alcohol. Acetic acid can also be produced from the oxidation of ethanol industrially.  Acetic acid has been used for thousands of years for the preservation of foods by increasing acidity and inhibiting bacterial growth. It is mostly used where its flavour contributes to the product e.g. in pickles, sauces, marinades and salad dressings. Acetic acid is however more effective against yeasts and moulds than bacteria, with lactobacilli being resistant. Acetic acid has quantum satis status in the EU.

Lactic acid (E270)

Lactic acid (E270) is commercially made from fermentation of sugar or glucose and not from dairy products as may be suggested. Lactic acid has a mild flavour compared with other acids and is used in foods such as yoghurts, processed cheese, pickled vegetables, salads, low-fat mayonnaise, confectionery and some breads. It is effective against both food spoilage and food borne pathogenic bacteria. In combination with acetic acid it inhibits the growth of yeast.  It is used in confectionery to mask the off-flavours from intense sweeteners where these are used. It has quantum satis status in the EU.

Proprionic acid, propanoic acid (E280)

Proprionic acid, propanoic acid (E280) is a naturally occurring acid and is a normal constituent of bodily fluids and is produced from lactic acid using Proprionicbacterium or from oxidising propionaldehyde. It also occurs naturally in ripe Swiss and Jarlsberg cheeses and in the rumen of ruminant mammals. It is used mainly as a mould inhibitor to extend the shelf-life of foods such as bread, cheese and cheese products. High levels of proprionic acid can create bitter, cheesy flavours and reduce the activity of baker’s yeast, which then has to be increased in yeast leavened products. Propionic acid is also used as sodium propionate (E281), calcium propionate (E282) and potassium propionate (E283) as these salts yield the free acid when used in manufacture. They are all considered together in regulatory terms.

The use of propionic acid is controlled in the EU by Regulation 1129/2011 – this only allows its use in a limited number of foods, with individual limits in each case. Propionic acid and the propionates have a joint ADI of 0-6.0mg/kg body weight per day.

EFSA re-reviewed 2014 Re-evaluation of propionic acid – propionates (E 280-283) | EFSA

Boric acid (E284)

Boric acid (E284) is produced from the natural mineral sodium tetraborate (borax) (E285) by reacting borax with sulphuric acid. Borax has been used as a household disinfectant for many years and in the EU it is permitted in food only in caviar to a maximum of 4g/kg.

Malic acid (E296)

Malic acid (E296) occurs naturally in many fruits, but is produced commercially from maleic anhydride. Malic acid has a mild sour taste and is less sharply acidic than citric acid so is used for a sour taste that is less immediate but lingers for longer. It is often used in products which contain high intensity sweeteners and it has a lower melting point than citric acid so is used in some boiled sweets. In the EU malic acid has quantum satis status and is used in fruit drinks, sweets, chewing gum, sorbets, jams, snacks and sweet and sour sauces.

Fumaric acid (E297)

Fumaric acid (E297) occurs naturally in plants and mushrooms, but is manufactured from fermentation of maleic acid. It can increase acidity without having a big impact on taste and is used in fillings and toppings for bakery products, confectionery, deserts and powdered dessert mixes, instant powders for fruit, tea or herbal based drinks. It is also permitted in some wines.

EU 1129/2011 regulates the products it can be used in in the EU but no ADI has been specified. Along with succinic acid it is currently undergoing re-evaluation by EFSA Call for data for the re-evaluation of fumaric acid (E 297) and succinic acid (E 363) as food additives | EFSA but there are no immediate safety concerns.

Vitamin C, Ascorbic acid (E300), Sodium ascorbate (E301) and Calcium ascorbate (E302)

Vitamin C, Ascorbic acid (E300), Sodium ascorbate (E301) and Calcium ascorbate (E302). Ascorbic acid occurs naturally in most fruits and vegetables, notably in citrus fruits. It is often extracted from rosehips but is made commercially from glucose. Sodium and calcium ascorbate are salts of ascorbic acid. In solution ascorbate is easily oxidised to dehydroascorbate. Ascorbic acid is added to foodstuffs that will be exposed to oxygen during storage with the intention that it is oxidised in place of the other food ingredients. This extends shelf-life and delays the generation of off-flavours. Because ascorbic acid readily reacts with oxygen it is very effective at protecting other ingredients from oxidation and can work alongside other antioxidants as it has little flavour. It can be used quantum satis in the EU and is typically used in bread and canned fruit and vegetables.

Citric acid (E330)

Citric acid (E330) occurs very widely in nature, notably in citrus fruits. Whilst it was first produced from lemons it is now made from large-scale fermentation of sugars. Its primary function in food is as an acid to increase acidity and reduce discolouration of spoilage of cut fruits, vegetables and shellfish. Citric acid has a clean tart taste and provides flavour as well as acidity. It has quantum satis status in the EU but its levels of use are restricted by its strong flavour. It is often used alongside sodium citrate (E331) or potassium citrate (E332) to more accurately control the acidity level.

Tartaric acid (E334)

Tartaric acid (E334) is made from the acid potassium tartrate from fermentation of grape juice or from malic acid. It has two main functions: for an acid taste and as part of baking powder. Tartaric acid has a different taste profile from citric acid with less fresh and more sour notes and is used in biscuits and jams. It has quantum satis status in the EU.

Sodium tartrates (E335) Monosodium tartrate, Disodium tartrate

Potassium tartrates (E336) Monopotassium tartrates, Dipotassium tartrates

Sodium potassium tartrate (E337)

These are all acidulants, with monopotassium tartrate formed as a by-product of the fermentation of grape juice, then reacted with sodium hydroxide to produce dipotassium tartrate. Sodium tartrates are produced from tartaric acid and sodium potassium tartrate is formed as a crystalline deposit during wine production. Monopotassium tartrate is known as ‘cream of tartar’ and used in baking powder as the source of acidity. Tartrates are also used as buffers and taste modifiers in products containing tartaric acid. Tartrates are permitted in the EU quantum satis.

Phosphoric acid (E338)

Phosphoric acid (E338) is manufactured from sulphuric acid on natural rock phosphate and is used for acidity in soft drinks, jams, cheese and beer. It is the only inorganic acid used extensively as a food acid. Phosphoric acid is one of the cheapest and strongest food grade acids and has a sharp acid flavour used in cola drinks. In the EU phosphoric acid is permitted in a range of products with individual limits in each. EFSA considered the safety of phosphoric acid alongside phosphates and polyphosphates in 2019. More information about this additive can be found by clicking on the bold underlined link.

Sodium phosphates (E339) Monosodium phosphate, Disodium phosphate, Trisodium phosphate and Potassium phosphates (E340) Monopotassium phosphate, Dipotassium phosphate, Tripotassium phosphates

Sodium phosphates (E339) Monosodium phosphate, Disodium phosphate, Trisodium phosphate and Potassium phosphates (E340) Monopotassium phosphate, Dipotassium phosphate, Tripotassium phosphates are produced by reacting metal hydroxides with phosphoric acid and the additives in this group are all largely interchangeable. Monometal phosphates are acidic and are used as acidulants in raising agents, but calcium phosphates (E3410 are used more frequently. These sodium and potassium phosphates are more commonly used as chelating agents, buffering agents and occasionally as emulsifying salts in processed cheese. They are also used for protein binding in mixtures of other phosphates. Dimetal phosphates are used as water binders in meat and dairy products preventing water loos and shrinkage during cooking and storage. They are also used to stabilise long life milk products such as evaporated milk, to increase the rate of gelling in instant puddings and cheesecakes and as emulsifying salts in processed cheese products where they provide the required body and melting performance without fat separation. Tripotassium phosphate is used as a buffering agent and texturiser in meat and cheese products and is also used to increase the speed of cooking of pea, beans and cereals. In the EU phosphates are permitted in a range of products with individual maxima in each case.

Metatartaric acid (E353)

Metatartaric acid (E353) is only permitted for use in wine up to 100mg/litre and is used to prevent deposits of tartrate salts during storage.

Adipic acid (E355)

Adipic acid (E355) is produced by the oxidation of cyclohexane and is only permitted for use in the EU in fillings for bakery products, dessert mixes and drink powders with individual limits for each use. It has an ADI of 0-5mg/kg body weight.

Succinic acid (E363)

Succinic acid (E363) occurs naturally in a range of vegetables but is made commercially from acetic, fumaric or maleic acids to provide a distinctive acidic taste. It is permitted in desserts, soups and drink powders with maximum permitted levels for each.

Alginic acid (E400)

Alginic acid (E400) is extracted from brown seaweed and swells in water but does not dissolve. The commercial product is extracted from a wide range of brown seaweed species from the North Atlantic, California, Mexico and South America. Most is extracted from material growing naturally but there is some seaweed cultivation in China. Alginic acid swells in water but does not dissolve and its main application is in pharmaceutical tablets.  It is used in antacid tablets but rarely added to food, occasionally used in ice-cream and whipped cream as a stabiliser. It is not absorbed by humans and has quantum satis status

Gluconic acid (E574)

Gluconic acid (E574) is an organic acid occurring naturally in plants, fruit, wine and honey, but is commercially prepared from glucose oxidation. It has mild acid properties and is used where the taste of one of the other acids may be unsuitable in soft drinksm confectionery and fruit preparations. It has quantum satis status in the EU.

Hydrochloric acid (E507)

Hydrochloric acid (E507) is made industrially from salt or as a by-product of chlorinated chemicals and is strongly acidic. It is very cost-effective when used to increase acidity and has a less distinct taste than other acids. It is used in a number of ways not just as an acid: e.g. to produce invert sugar from sucrose and glucose syrups from starch, the hydrolysis of vegetable proteins. Whilst hydrochloric acid is highly corrosive and must be handled with care to avoid skin contact, once diluted for food use is considered harmless and has quantum satis status.

Sulphuric acid (also called sulfuric acid) E513

Sulphuric acid (also called sulfuric acid) E513 is made industrially from sulphur dioxide and is a strong and cost effective acid. Whilst it is corrosive and must be handled with care to avoid skin contact once diluted for food use it is harmless and has quantum satis status in the EU.

Acidity regulators

Acidity regulators are used to moderate the acidic taste.

Potassium acetate (E261)

Potassium acetate (E261) is made by the reaction of acetic acid and potassium carbonate. It is used to modify the flavours of products acidified with acetic acid, but does not increase the sodium content as the acidity regulator sodium acetate does. Potassium acetate has quantum satis status in the EU.

Sodium acetate and sodium diacetate (E262)

Sodium acetate and sodium diacetate (E262) produced from the reaction of acetic acid with sodium hydroxide (when the sodium acetate crystallises it is called sodium diacetate). Sodium acetate acts as an acidity regulator modifying the taste of acetic acid but sodium diacetate has a specific use in bread production where it is used to protect against the growth of some spore forming bacteria. It is also used as a flavouring for dry products to give the flavour of vinegar.  The sodium acetates have quantum satis status in the EU and are typically found in bread, flavoured snacks and instant soups.

Calcium acetate (E263)

Calcium acetate (E263) is made by the reaction of acetic acid and calcium hydroxide and is used both as an acidity regulator and to provide calcium as a source of fortification. Calcium acetate has quantum satis status in the EU.

Sodium lactate (E325) and potassium lactate (E326)

Sodium lactate (E325) and potassium lactate (E326) are produced from lactic acid and sodium or potassium hydroxide mix and their main function is regulate acidity and control spoilage. They are typically used in meat and fish products  and potassium lactate is one of the least bitter tasting potassium salts and is also used where sodium reduction is required. Both have quantum satis status.

Calcium lactate (E327)

Calcium lactate (E327) is produced by neutralisation  of lactic acid by calcium hydroxide, chalk or lime. It is used in food as a source of calcium but also as an acidity regulator in fruit products such as soft drinks, fruit pastes, pickles and canned fruit. It is one of the few calcium sources that is soluble in low pH environments like fruit juices, beverages and pickles and neutral pH environments (such as milk, baby food). It has a neutral flavour and the calcium is highly bioavailable and easily metabolised. Research has shown that inclusion of calcium lactate in savoury snacks can reduce the level of acrylamide formation (X-ref to acrylamide in contaminants). In the EU is it permitted quantum satis as an additive, but different regulations apply if it is used as a fortificant in food (Regulation 1925/2006).

Sodium citrates – monosodium citrate, disodium citrate and trisodium citrate (E331)

Sodium citrates – monosodium citrate, disodium citrate and trisodium citrate (E331) are found widely in nature but produced commercially by neutralising citric acid with sodium hydroxide or carbonate. These are used as acidity regulators, often alongside citric acid. Trisodium citrate is also used as an emulsifier salt in processed cheese. They have quantum satis

status in the EU and are typically used in soft drinks, desserts, confectionery and jams.

Potassium citrates (E332)

Potassium citrates (E332) includes monopotassium citrate and tripotassium citrate. These are commercially produced from citric acid and used as acidity regulators, emulsifying salts and a source of potassium in food. Typically used in drinks and confectionery it has quantum satis status in the EU but can have a diuretic effect.

Calcium citrates (E333)

Calcium citrates (E333) includes monocalcium citrate, dicalcium citrate and tricalcium citrate. These are made commercially from citric acid and are used as both acidity regulators, emulsifying salts and sources of calcium. They are often used in dietary supplements and processed vegetables. They have quantum satis status in the EU.

Sodium malates (E350), potassium malate (E351) and calcium malates (E352)

Sodium malates (E350), potassium malate (E351) and calcium malates (E352) are made by reacting malic acid with the appropriate hydroxide or carbonate and as used as acidity regulators alongside malic acid. They complement the flavour of many products such as those with apple flavour and have quantum satis status in the EU. They are often used in jams and jellies.

Sodium adipate (E356) and potassium adipate (E357)

Sodium adipate (E356) and potassium adipate (E357) are made by reacting adipic acid with the appropriate hydroxide or carbonate and are used as acidity regulators where adipic acid is used. As with adipic acid they are only allowed in a few specific products with limits for their use in each.

Triammonium citrate (E380)

Triammonium citrate (E380) is produced from citric acid and ammonium hydroxide and has little use in the food industry beyond as a yeast food and a chelating agent, but falls into the category in acidity regulators. It is permitted quantum satis in the EU.

Sodium hydroxide (E524)

Sodium hydroxide (E524) is manufactured from the electrolysis of salt and is strongly alkaline so can be used to decrease the acidity (increase the pH) of food products. Because it is a strong base it is very cost-effective as it can be used at very low levels. It is used to neutralise acids and stop the reaction in the production of invert sugar. It is also used in the alkalisation of cocoa power the hydrolysis of proteins as well as to improve potato peeling efficiency in potato processing. Sodium hydroxide is caustic and while safe in foods as very small amounts are used precautions are needed for those working with it and it needs to be kept in sealed containers as it absorbs water and carbon dioxide from the atmosphere. It is permitted quantum satis in the EU.

Potassium hydroxide (E525)

Potassium hydroxide (E525) is manufactured by electrolysis of naturally occurring potassium chloride. It is a strong base and can be used to reduce acidity. It is more expensive than sodium hydroxide but is used where the amount of sodium in a product must be limited. It needs to be mixed rapidly into any formulation so that local increases in pH do not occur and it is also very caustic so while safe in food in very small amounts workers must be protected. It can be used quantum satis in the EU.

Calcium hydroxide (E526)

Calcium hydroxide (E526) is made industrially by adding water to calcium oxide (E529) and is commonly known as slaked like. It is a weak alkali and is used to lower acidity and in the purification of sugar. It is also used in fruit pulp to preserve the integrity of fruit particles and is permitted quantum satis in the EU.

Ammonium hydroxide (E527)

Ammonium hydroxide (E527) is prepared by passing ammonia gas into water to make an alkali base which can reduce the acidity in food. It decomposes on heating and is only available as a solution in water and is not commonly used. It can be used quantum satis in the EU.

Magnesium hydroxide (E528)

Magnesium hydroxide (E528) is manufactured from the natural mineral ore dolomite by heating and hydration and can be extracted from seawater. It is commonly used as an antacid in pharmaceuticals but can be used to reduce acidity in foods. It also provides a source of magnesium and is added to fortified foods. It is permitted quantum satis in the EU.

Calcium oxide (E529)

Calcium oxide (E529) is made by heating limestone and is used as a source of calcium hydroxide (E526). It is also used as a dough conditioner in bread making and in the production of maize tortillas. It is permitted quantum satis in the EU.

Magnesium oxide (E530)

Magnesium oxide (E530) is made by industrially heating naturally occurring sodium carbonate and is used as a source of magnesium hydroxide (E528). It is typically used in fortified foods and can be used quantum satis in the EU.

Sodium gluconate (E576), Potassium gluconate (E577), Calcium gluconate (E578) and Ferrous gluconate (E579)

Sodium gluconate (E576), Potassium gluconate (E577), Calcium gluconate (E578) and Ferrous gluconate (E579) are all made from fermentation of glucose and subsequent chemical modification and their primary uses are not in the food industry where they are used it is to reduce the bitterness of other ingredients, for fortification, for acidity regulation in soft drinks and as a component of salt replacers. Sodium gluconate is used in low sugar chewing gum, potassium gluconate in baked goods, milk drinks, sport drinks and nutritional bars and calcium gluconates in drinks, desserts and dairy products. Their use as fortificants is controlled by EU Regulation 1925/2006 but as additives they have quantum satis status. Ferrous gluconate is only permitted for use in olives darkened by oxidation to a maximum of 150mg/kg.

Carbamide (E927b)

Carbamide (E927b) is made by reacting ammonia with carbon dioxide and is made in large volumes for use in agriculture and pharmaceuticals. In food it is only permitted in the EU in chewing gum to a maximum of 30g/kg. It is used in chewing gum to reduce the acidity of saliva generated on chewing to reduce acid attack on the teeth.