The food additive acetic acid is an organic acid formed by the metabolism of nutrients and by vinegar fermentation. Along with its acetate salts, it is a normal metabolic intermediate produced by such bacteria as Acetobacter. It may also sometimes be synthesized de novo from carbon dioxide such as by microorganisms like Clostridium thermoaceticum. Acetic acid or acetates are present in most plant and animal tissues, in small amounts. In humans, it is involved in fatty acid and carbohydrate metabolism found as acetyl CoA. The molecular formula of acetic acid is CH3COOH. It appears as a clear colorless liquid and has a vinegar-like odor and a sharp, acid taste.
How is Acetic Acid Used in Foods?
Acetic acid is used in foods as a flavor enhancer and flavoring agent; an acidifier, color diluent, curing, and pickling agent, pH control agent, solvent, and preservative. It is generally recognized as safe when used in accordance with good manufacturing practice (21 CFR 184.1005)
What Foods Use Acetic Acid as an Ingredient?
As a food ingredient, it is found commonly in marinades, mustard, catsup, vinaigrettes and salad dressings, sauces, canned fruits, and mayonnaise. It may also be found in pickled products such as pickled sausages and pigs feet. It has a multitude of uses in meat, poultry, milk, and cheese products. It is also used as a boiler water additive, suitable for steam that contacts food. It is also an effective means of cleaning and sanitizing food preparation equipment and utensils.
How Much Acetic Acid is in Vinegar?
Commercial vinegar must contain at least 4% acetic acid. Vinegars, such as apple cider vinegar, are the product of fermented alcohol, which is commonly derived from wine, cider, or fermented fruit juice or beer. The ethyl alcohol in the fermented product is oxidized to acetaldehyde which is then converted to acetic acid through the action of the above-mentioned Acetobacter. when it is combined with sodium bicarbonate, carbon dioxide is released as a leavening agent.
What are Other Forms of Acetic Acid?
The acetate derivatives of acetic acid, calcium, sodium, or potassium salts, are substituted for acetic acid in some products, and can sometimes be used interchangeably with the acid form, having the same antimicrobial properties and the same pH values.
High concentrations of acetic acid, like any acid, can cause irritation or severe injury, including skin burns or allergic-like responses, airway and lung injury, and if ingested, moderate to severe gastrointestinal injury, depending on the concentration. Other complications are also possible, including renal failure and interference with blood clotting.