Acidification of food products

The United States Food and Drug Administration (FDA) has defined an “acidified food” as a low-acid food to which acid(s) or acid food(s) has been added to the product to produce a finished equilibrium pH of 4.6 or below and a water activity greater than 0.85.

In acidified foods, the addition of low-acid ingredients significantly alters the pH of the acid food ingredients in the product. The acidified food regulations apply to shelf-stable foods that are sold without refrigeration in sealed containers.

Certain dairy products, such as sour cream and fermented vegetables, such as sauerkraut are preserved through lactic acid produced by the growth of bacteria together with the holding of these products refrigerator temperatures above freezing.

When sauerkraut is canned, it is given a heat process sufficient to destroy all spoilage and disease microorganisms.

Acidified, low acid foods must be acidified to a pH of 4.6 or less. Preferably the pH should be less than 4.6 to allow a safety margin. Optimal flavor profiles for most products are reached at approximately pH 4.2. If the flavor is slightly acidic the flavor profile may be balanced with the addition of a small quantity of sugar.

The manufacturer of acidified foods must register their establishment and file a scheduled process established by a competent process authority. In addition, the operation must be under the supervision of an individual who has successfully completed an FDA approved course on processing acidified foods.
Acidification of food products