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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