FOOD ACIDULANTS

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ACIDULANTS

Acids and their salts Which serve a variety of functions in foods

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Definition of acidulants

• Definition Any substance that is added to food or drink to give or improve sour taste and odour. Additives that give a sharp taste to foods. They also assist in the setting of gels (consistency) and to act as preservatives.

• Many natural foods are acidic. Ex : oranges, lemons, apples, tomatoes, cheese and yoghurt contain natural acids, such as citric acid, that give them their characteristically sharp taste.

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COMMONLY USED ACIDULANTS

A. Phosphoric acid and phosphates

B. Hydrochloric acidC. Sulfuric acidD. Acetic acid and its saltsE. Propionic acid and its saltsF. Lactic acid and its

derivativesG. Succinic acid and succinic

anhydrideH. Fumaric acid and its salts

I. Malic acid and malic anhydride

J. Tartaric acid and its saltsK. Adipic acidL. Citric acid and its saltsM. Benzoic acid and its saltsN. Sorbic acid and its saltsO. Caprilyc acidP. Butyric acidQ. Glucono delta lactoneR. Amino acids

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CLASSIFICATIONTYPE ExamplesINORGANIC Phosphoric acid, HCl, sulfuric acid

ORGANIC Amino acids Lysine, Cystein, Glutamic acid

Lactones Ascorbic acid, gluconolactone

Fatty acids Sorbic acid, caprylic acid, butyric

Phenolic acids Benzoic acid

Carboxyclic acid

Monocarboxylic acid

Acetic acid, propionic acid, lactic acid

Dicarboxylic acid Succinic acid, fumaric acid, malicacid, tartaric acid

Tricarboxylic acid Citric acid

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FUNCTIONSPH CONTROL

AGENT

VISCOSITY AND MELTING MODIFIER

CHELATING AGENT

NUTRITIVE VALUE

FLAVOR ADJUNCTS

PRESERVATIVES /ANTIMICROBIAL

AGENTS

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• Type :- Acetic - Citric- Fumaric- Malic- Lactic - Tartaric- Phosphoric

Function :• Hydrolyze sugar into invert

sugar prolong shelf life.• Enhance/improve flavor :

lime, lemon, grape, cherry.• Decrease pH

Antimicrobial agent.• Metal Chelator (Cu, Fe)• Influence viscosity

“gelling”

Optimum pH is essential for processing or stabilizing a food system. Maintaining or establishment of pH by serving as buffering agents. Usually a combination of free acids and salts are used.

EXP : Important for gel-type products such as gelatin desserts,

jams, jellies, pectin gels, and jellied candy Determining factor is the amount of acid required Consideration must be given to the rate of sucrose

inversion Maintain acidic pH and function of leavening agents

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PH CONTROL AGENT

Reduction of the pH to prevent or retard the growth of microorganisms and the germination of spores; and to increase the lethality of the process.

EXP : The microbial action requires pH 3-5 to produce acids An acidic pH often shorten the sterilization time As antibrowning aids in preserving the quality of fruits and

vegetables Acidulant perform a bacteriostatic function in processed food A proper pH control is extremely important in foods where

benzoates, sorbates, and propionate are used as preservatives9WDR 2012

PRESERVATIVES / ANTIMICROBIAL AGENT

The presence of trace metal in any food products produce undesirable reaction such as discoloration, rancidity, and instability of nutrients. The sequestering ability of acidulants prevents such types of undesirable reactions

EXP.Chelation of metal ions to assist in minimizing lipid oxidation (Cu, Fe), reducing color changes and controlling texture in some fruits and vegetables

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CHELATING AGENTS / ANTIOXIDANT SYNERGIST

Enhance food flavors, The characteristics flavor of some acids make them particularly useful with certain flavorExp :• Foods such as hard candies, gelatin desserts, carbonated

and non carbonated beverages, jellies, preserves, toppings, and many other products would taste flat

• Acidulants add the tartness required to balance the excessive sweetness of these products

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FLAVOR ADJUNCTS

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FLAVOR ADJUNCTS

For examples: tartaric acid in combination with grape flavor; phosphoric acid with cola flavor; citric, fumaric, and malic acids are compatible with most fruit flavor

The degree of tartness has marked effects on flavors. Citric acid as clean, malic as smooth, fumaric as metallic, adipic as chalky, vinegar as astringent, tartaric as bitter or sharp, and lactic acid as sour

Succinates and acetates react with gluten and modifiy their plastic behavior

Acidulants affect softening point, melt properties, and texture for cheese, margarine, and hard candy

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PH CONTROL AGENTVISCOSITY AND MELTING MODIFIER

1. Flavor

2. Acidity

3. Metal Chelating Activity

4. Anti-microbial Activity

5. Solubility

6. Hydroscopicity

7. Cost

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MORE ATTENTION AND CONSIDERATION OF ACIDULANTS

pKa’s of Food Acids

ACID pKa• Acetic 4.75• Phosphoric 2.1, 7.2, 12.3• Citric 3.08, 4.74, 5.4• Lactic 3.86• Hydrochloric• Sulfuric --, 1.92• Carbonic 6.4,10.3• Malic 3.4, 5.1

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pKa’s of Food Acids

ACID pKa• Succinic 4.2, 5.6• Tartaric 3.2, 4.8• Fumaric 3.03, 4.44• Adipic 4.43, 4.41• Gluconic 3.60• Pyrophosphoric 0.9, 1.5, 5.8, 8.2

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Solubility

Varies with acid– Degree and rate varies with temperature– Fumaric – poorly soluble in cold water– Encapsulation sometime used to delay

solubility

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Taste of AcidsTaste Response of Acids

0

10

20

30

40

50

60

70

0 20 40 60 80

Time

Malic Acid

Citric Acid

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Solubility of more soluble acids

Solubility of Acids

0

50

100

150

200

250

0 20 40 60 80 100 120

Temp C

Sol

ub

ilit

y %

(w

/w)

Malic Acid

Citric Acid

Tartaric Acid

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Moisture Absorption

Moisture Absorption

0

50

100

150

200

0 50 100 150

Time (Hr)

% G

ain

in

Wei

gh

t

Malic

Citric

Tartaric

Adipic,Succinic,Fumaric

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Citric Acid

Accounts for 60% of all acids used.

Helps preserve color, aroma and and vitamine content of canned foods

pH control, strong chelator, antioxidant, synergist

Excellent solubility

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Citric Acid

Provided buffering capacity pH 2.5-6.5

Cultured dairy products-substrate for flavor production

Processed cheese-alter protein and emulsify

Evaporated milk-stabilize protein to heat

Honey-retard crystallization

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Lactic Acid

FlavorModerate chelatorpH adjustmentAnti-microbial activityCoagulating agent

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Malic Acid

Flavor Moderate chelator pH adjustment

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Tartaric Acid

Moderate chelatorBuffering capacity pH 3.5-4.5Baking powder-leavening acidFruit butters, jams, sherbets, jellies-

flavor, pHHard candies-flavor, crystallization

controlArtificial sweetener - bitter

masking25WDR 2012

Phosphoroc Acid and PhosphatesPhosphate Food Additives Recognized as GRAS

by the FDA

Miscellaneous and General Purpose Food Additives

Phosphoric acid Ammonium phosphate (mono, dibasic) Sodium acid pyrophosphates Calcium phosphate (mono, di, tribasic) Sodium phosphate (mono, di, tribasic) Sodium tripolyphosphates

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The Application of Phosphoric Acid

Phosphoric acid the least expensive of all food grade acidulants

Phosphoric acid in strongest and giving the lowest attainable pH

Application in cola, root beer, soft drink, and similar flavor carbonated beverages

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The Application of Phosphoric Acid

Used in cheeses and brewing to adjust pH

Used as yeast stimulantNeutralize the caustic

peeling of fruitTo clarify and acidify collagen

in the production of gelatinPurification of vegetable oilsThe small extent in

manufacturing of jams and jellies

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Hydrocloric acid• Rarely used as an acidulant, it finds many

application in the food industry• Permitted as acidulant by the FAO (1974)• Used to produce the chloride salts of several

important food additives• Used in process that require hydrolysis of

starting materials such as proteins and starches• It is used in production of corn syrup

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