Foods with a pH of <4.6 are called "Acid Foods" Some types of acid foods, such as acidified foods, are subject to specific regulation.
What are Acid Foods?
Acid Foods: A food with a natural pH of ≤4.6. There are many naturally acidic foods, including apples, yogurt, peaches, onions, tomatoes, strawberries and lemons.
"Acid Foods" as a general group are not regulated, although certain sub-groups of acid foods are.
Types of Acid Foods
There are two main types of acid foods
Acidified Food: These are low-acid foods that has been acidified by adding something acidic so that the end product is ultimately acidic has an equilibrium pH of ≤4.6) . This includes foods such as: dill pickles, hot sauce, and pickled fish.
The FDA does not include the following to be Acidified Foods:
Carbonated Beverages
Jams, jellies & preserves
Naturally acid foods like peaches and most fruit juices
Foods with a water activity of ≤0.85
Foods which are stored under refrigeration
Fermented foods (i.e. kimchi, sauerkraut, natto)
The FDA regulates acidified foods in 21 CFR Part 114.
Formulated Acid Foods: These are composed mostly of acid foods to which a small amount of low-acid ingredients are added (generally less than 10% by weight). The low proportion of low-acid ingredients means that the pH doesn't change significantly from the pH of the dominant ingredients. Examples include:
Barbecue Sauce
Salad Dressings
Marinades
Use this key to determine if your food is an acidified food.
FAQ
Is my product an Acidified Food?
Consider this flow chart to determine if your product is regulated by the FDA as an Acidified Food:
Click to enlarge
What's the difference between an acidified food and a formulated acid food?
The difference between these two types acid foods depends on the proportion of low acid and high-acid ingredients in each product:
Acidified foods are typically low acid foods with an added acid (which acidifies the low acid food.)
Formulated Acid foods are composed mainly of high acid foods with a small amount of low acid foods added.
Formulated Acid Foods
In order to qualify as a "formulated acid food", the low-acid ingredients must not significantly shift the pH of the product from the natural pH of the high-acid ingredients.
For a food product whose equilibrium (final) pH is <4.0, then a shift of up to 0.4 is considered insignificant.
For a food product whose equilibrium (final) pH is >4.0, then a shift of up to 0.1 is considered insignificant.:
Example #1: Ned's BBQ Sauce.
Ingredients by weight: Tomato paste (93%), Sugar (5%), Spices (2%)
Ned's BBQ Sauce Equilibrium pH: 3.9
pH of only High-Acid Ingredients: 3.6
Change between high-acid ingredients and final product = 0.3
Since the equilibrium pH of Ned's BBQ Sauce is below 4.0, only an increase of 0.4 or more would be considered significant. Since the low-acid ingredients only increase the pH by 0.3, this change is considered insignificant.
Outcome: Ned's BBQ Sauce is a Formulated Acid Food. It is not subject to 21CFR Part 114
Example #2: Ned's Marinade
Ingredients by weight: Tomatoes (60%) Onion (10%) Vinegar (20%) Sugar (7%) Spices (3%)
Ned's Marinade Equilibrium pH: 4.2
pH of only High-Acid Ingredients: 4.0
Change between high-acid ingredients and final product = 0.2
Since the equilibrium pH of Ned's BBQ Sauce is above 4.0, an increase of above 0.1 would be considered significant. Since the low-acid ingredients increase the pH by 0.2, this change is considered significant.
Outcome: Ned's BBQ Sauce is an acidified food. As a result, it is subject to The regulations in 21 CFR Part 114.
