Manufacture of traditionally fermented vegetable products: Best practice for small businesses and retail food establishments

Authors: SNYDER, ABIGAIL - Cornell University; Breidt, Frederick; ANDRESS, ELIZABETH - University Of Georgia; INGHAM, BARBARA - University Of Wisconsin

Submitted to: Food Protection Trends
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2020
Publication Date: 7/1/2020
Citation: Snyder, A., Breidt, F., Andress, E.L., Ingham, B.H. 2020. Manufacture of traditionally fermented vegetable products: Best practice for small businesses and retail food establishments. Food Protection Trends. 40(4):251-263.

Interpretive Summary: Vegetable fermentations have become increasingly popular, but there is little information available about safety of common fermentation practices. In this manuscript we address the basic critical controls needed to safely manufacture “traditional” fermented vegetable products, principally cucumber and cabbage fermentations. The information is targeted primarily at small commercial producers but may be generally useful to all those interested in vegetable fermentation safety. The basic scientific knowledge about how vegetable fermentation ecology develops, and changes is outlined along with a literature review of the topic. The factors that are important in microbial safety, including temperature, pH, salt concentration and other variables are examined, and recommendations are made for safe fermentation practices with an example of kimchi fermentation.

Technical Abstract: Fermentation has a long tradition of improving the shelf life, acceptability, and safety of some food and beverages. Under the Food Safety Modernization Act, a business that manufactures fermented foods may be required to conduct a risk analysis and establish pertinent preventive controls. Retail food establishments operating under the FDA Food Code must often seek a variance for manufacture of fermented foods and beverages. Developing food safety programs can be a challenge for small-scale producers with little access to training and resources, especially as manufacture of fermented products involves microbiologically complex systems that may not be effectively or appropriately managed by standard time-temperature controls. We review the science behind traditional vegetable fermentation processes, e.g., cabbage, cucumbers and peppers, and discuss identification of relevant hazards based on intrinsic and extrinsic factors inherent in the fermentation systems that influence microbial survival. We advocate for one Critical Control Point (CCP) in the manufacture of traditionally fermented vegetable products, namely a steady and sustained pH decline to < 4.6. We outline additional Control Points (CPs) at key steps, i.e., vegetable preparation and salt addition; fermentation time and temperature; refrigerated storage; and/or packaging for shelf stability. We illustrate these best practices with an example of kimchi manufacture.