| As a flavor ingredient |
Identification
| CAS.No.: |
124-04-9 |
FL.No.: |
8.026 |
FEMA.No.: |
2011 |
NAS.No.: |
2011 |
| CoE.No.: |
26 |
EINECS.No.: |
204-673-3 |
JECFA.No.: |
623 |
E.No.: |
E355 |
Description: Adipic acid is a crystalline powder with practically no odor. It has the lowest acidity of any of the acids commonly used in foods and has excellent buffering capacity in the range of pH 2.5 to 3.0. Like succinic and fumaric acid, adipic acid is practically nonhygroscopic. Its addition to foods imparts a smooth, tart taste. In grape-flavored products, it adds a lingering supplementary flavor and gives an excellent set to food powders containing gelatin. As a result, adipic acid has found a wide number of uses as an accidulant in dry powdered food mixtures, especially in those products having delicate flavors and where addition of tang to the flavor is undesirable.
Its aqueous solutions have the lowest acidity of any of the common food acids. For concentrations from 0.5 to 2.4 g/100 mL, the pH of its solution varies less than half a unit. Hence, it can be used as a buffering agent to maintain acidities within the range of 2.5 to 3.0. This is highly desirable in certain foods, yet the pH is low enough to inhibit the browning of most fruits and other foodstuffs.
Regulatory Status:
CoE: Approved
FDA: 21 CFR 131.111, 184.1009, 582.1009
FDA (other): n/a
JECFA:ADI: 0–5 mg/kg bw (1977). No safety concern when used at current levels as a flavoring agent (1999).
Reported uses (ppm): (FEMA, 1994)
| Food Category |
Usual |
Max. |
| Alcoholic beverages |
40 |
40 |
| Baked goods |
0.04 |
0.13 |
| Condiments, relishes |
14.01 |
14.09 |
| Fats, oils |
2700 |
2700 |
| Gelatins, puddings |
3.4 |
4 |
| Gravies |
0.75 |
1 |
| Imitation dairy |
4250 |
4250 |
| Instant coffee, tea |
0.01 |
0.04 |
| Meat products |
2.67 |
2.67 |
| Nonalcoholic beverages |
0.04 |
0.05 |
| Poultry |
0.15 |
0.15 |
| Snack foods |
0.5 |
1.86 |
Natural occurrence: Reported found as a minor constituent in butter, and has been found in other fats as a product of oxidative rancidity. It also occurs in beet juice, pork fat, guava fruit (Psidium guajava L.), papaya (Carica papaya L.) and raspberry (Rubus idaeus L.). |
| Chemical Properties |
white crystalline powder |
| Uses |
progestin |
| Uses |
Adipic Acid is primarily used in the synthesis of nylon. It has been used as a reagent in the solid-state polymerization of nylon analogs. |
| Definition |
ChEBI: An alpha,omega-dicarboxylic acid that is the 1,4-dicarboxy derivative of butane. |
| General Description |
Adipic acid is a white crystalline solid. Adipic acid is insoluble in water. The primary hazard is the threat to the environment. Immediate steps should be taken to limit its spread to the environment. Adipic acid is used to make plastics and foams and for other uses. |
| Air & Water Reactions |
Dust may form explosive mixture with air [USCG, 1999]. Insoluble in water. |
| Reactivity Profile |
Adipic acid is a carboxylic acid. Carboxylic acids donate hydrogen ions if a base is present to accept them. They react in this way with all bases, both organic (for example, the amines) and inorganic. Their reactions with bases, called "neutralizations", are accompanied by the evolution of substantial amounts of heat. Neutralization between an acid and a base produces water plus a salt. Carboxylic acids with six or fewer carbon atoms are freely or moderately soluble in water; those with more than six carbons are slightly soluble in water. Soluble carboxylic acid dissociate to an extent in water to yield hydrogen ions. The pH of solutions of carboxylic acids is therefore less than 7.0. Many insoluble carboxylic acids react rapidly with aqueous solutions containing a chemical base and dissolve as the neutralization generates a soluble salt. Carboxylic acids in aqueous solution and liquid or molten carboxylic acids can react with active metals to form gaseous hydrogen and a metal salt. Such reactions occur in principle for solid carboxylic acids as well, but are slow if the solid acid remains dry. Even "insoluble" carboxylic acids may absorb enough water from the air and dissolve sufficiently in Adipic acid to corrode or dissolve iron, steel, and aluminum parts and containers. Carboxylic acids, like other acids, react with cyanide salts to generate gaseous hydrogen cyanide. The reaction is slower for dry, solid carboxylic acids. Insoluble carboxylic acids react with solutions of cyanides to cause the release of gaseous hydrogen cyanide. Flammable and/or toxic gases and heat are generated by the reaction of carboxylic acids with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Carboxylic acids, especially in aqueous solution, also react with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Their reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still heat. Like other organic compounds, carboxylic acids can be oxidized by strong oxidizing agents and reduced by strong reducing agents. These reactions generate heat. A wide variety of products is possible. Like other acids, carboxylic acids may initiate polymerization reactions; like other acids, they often catalyze (increase the rate of) chemical reactions. Behavior in Fire: Melts and may decompose to give volatile acidic vapors of valeric acid and other substances. |
| Health Hazard |
Inhalation of vapor irritates mucous membranes of the nose and lungs, causing coughing and sneezing. Contact with liquid irritates eyes and has a pronounced drying effect on the skin; may produce dermatitis. |
| Fire Hazard |
Behavior in Fire: Melts and may decompose to give volatile acidic vapors of valeric acid and other substances. Dust may form explosive mixture with air. |
