UC Food Safety
University of California
UC Food Safety

Acidified Foods

Approximate pH of Foods and Food Products (FDA) 

The pH and/or acidity of a food are generally used to determine processing requirements and applicability of specific regulations. The approximate ranges of pH values of common food products are compiled by the FDA in this table (FDA, 2007).

Acidified Low-Acid Foods

Non-acidic products, including most vegetables and fresh meat can be acidified to produce acidified low-acid foods. These products are commonly called “pickles” or “pickled products”. Because there is a risk of botulism if these foods are not properly acidified and processed there are very specific regulations that pertain to these foods. Included in this section are a number of resources addressing this category of foods.

A number of acidic foods are not considered to fall into the acidified low-acid food category. To determine if your product is an acidified low-acid food consult the following document:

Acidified Low-Acid Food Q&A (L. Harris, UC Davis Food Sci & Tech) (PDF 11 KB)

Acidified Foods Manufacturing School Manual (North Carolina State University & Grocery Manufacturer's Association)

 Regulations Pertaining to Acidified Low-Acid Foods

Acidified low-acid foods processed in California must comply with the California cannery regulations. (CA Dept. of Public Heath)  Associated forms from CDPH, except where noted below:

Acidified Low Acid Foods (FDA)

Instructions for Establishment Registration and Processing Filing for Acidified and Low-Acid Canned Foods - Paper Submissions

Instructions for Establishment Registration and Processing Filing for Acidified and Low-Acid Canned Foods - Electronic Submissions

This guide is a series of questions and answers concerning the importation of low-acid and acidifed foods. This pamphlet describes when and how processors of low-acid canned foods and acidified foods can register their establishments with the FDA.

Additional Information for Acidified-Low Acid Foods

Acidification of Garlic added to Oil  (FDA Safe Practices for Food Processes) Section 3.5

(Section 3.5 is copied below)

3.5. Garlic-in-oil1
Product: Garlic-in-oil.  The product is not held hot or cold.  The ingredients of the product are chopped fresh garlic and oil.  The product is intended to be distributed and stored at ambient temperature for extended shelf life.  Outbreaks have been associated with C. botulinum toxin in garlic-in-oil.  Microbiological hazards:  C. botulinum toxin production.

Step 1.  Processing:  Oil poured into chopped garlic in a bottle.  Although no heat is applied, vegetative pathogens are not associated with this food. Go to Table A.
Table A: pH> 4.6 and high aw (not specified).
Step 2.  Decision: Product may be a TCS food.
Product Assessment: No identified product characteristic that prevents spore-forming pathogen growth.  Antimicrobial properties of garlic will prevent the growth of vegetative pathogens. 
Decision options: Challenge testing, predictive microbial model, reformulation to lower pH with acetic  or phosphoric acid to < 4.6, refrigerate (TCS food), store hot (TCS food), or at ambient temperature for a limited time less than the estimated lag phase for the pathogens of concern, or not marketable.
1Flavored oil will present negligible hazard due to lack of C. botulinum survival or growth in 100% oil.

Cornell University

North Carolina State University

From the North Carolina State University Department of Food Science.  

When acidified low acid or low acid canned foods are shipped across state lines the food processor must register with the FDA in addition to the appropriate state agency. This article describes the process for filing a scheduled process with the FDA.

University of California, Davis 

University of Georgia

University of Tennessee

Site Creation date 6/1/2009
Webmaster for site:  Zann Gates

Webmaster Email: zgates@ucdavis.edu