CHAPTER 16: Pathogenic Bacteria Survival Through Cooking or Pasteurization This guidance represents the Food and Drug Administration’s (FDA’s) current thinking on this topic. It does not create or confer any rights for or on any person and does not operate to bind FDA or the public. You can use an alternative approach if the approach satisfies the requirements of the applicable statutes and regulations. If you want to discuss an alternative approach, contact the FDA staff responsible for implementing this guidance. If you cannot identify the appropriate FDA staff, call the telephone number listed on the title page of this guidance. UNDERSTAND THE POTENTIAL HAZARD. Pasteurization is a treatment (usually, but not always, the application of heat) applied to The survival of pathogenic bacteria through eliminate the most resistant pathogenic bacteria cooking or pasteurization can cause consumer of public health concern that is reasonably likely illness. The primary pathogens of concern are to be present in the food for as long as the shelf- Clostridium botulinum (C. botulinum), Listeria life of the product, when stored under normal monocytogenes (L. monocytogenes), Campylobacter and moderate abuse conditions. With fishery jejuni (C. jejuni), pathogenic strains of Escherichia products, pasteurization is usually performed after coli (E. coli), Salmonella spp., Shigella spp., Yersinia the product is placed in the hermetically sealed enterocolitica (Y. enterocolitica), Staphylococcus finished product container. It is applied to fishery aureus (S. aureus), Vibrio cholera (V. cholera), products that are distributed either refrigerated or Vibrio vulnificus( V. vulnificus), and Vibrio frozen. Examples of pasteurized fishery products parahaemolyticus (V. parahaemolyticus). See are pasteurized crabmeat, pasteurized surimi-based Appendix 7 for a description of the public health analog products, and pasteurized lobster meat. impacts of these pathogens. In addition to eliminating bacterial pathogens, It is not practical to target viral pathogens in cooking and pasteurization also greatly reduce cooking or pasteurization processes because of the number of spoilage bacteria present in the their extreme heat resistance. Viral pathogens fishery product. These bacteria normally restrict should be controlled through a rigorous sanitation the growth of pathogens through competition. regime as part of a prerequisite program or as Elimination of spoilage bacteria allows rapid part of Hazard Analysis Critical Control Point growth of newly introduced pathogenic bacteria. (HACCP) itself. The Procedures for the Safe and Sanitary Processing and Importing of Fish and Pathogenic bacteria that may be introduced after Fishery Products regulation, 21 CFR 123 (called cooking or pasteurization are, therefore, a concern. the Seafood HACCP Regulation in this guidance This is especially true for pasteurization, because document) requires such a regime. that process can significantly extend the shelf-life of the fishery product, providing more time for • Types of heat processing pathogenic bacteria growth and toxin formation. Cooking is a heat treatment, usually performed Retorting is a heat treatment that eliminates all before the product is placed in the finished product food-borne pathogens and produces a product container. It is applied to fishery products that are that is shelf stable. Mandatory controls for retorting distributed either refrigerated or frozen. Generally, are provided in the Thermally Processed Low-Acid after cooking, fishery products are referred to as Foods Packaged in Hermetically Sealed Containers cooked, ready to eat. Examples of cooked, ready- to-eat fishery products are crabmeat, lobster meat, regulation, 21 CFR 113 (hereinafter, the Low Acid crayfish meat, cooked shrimp, surimi-based analog Canned Foods (LACF) Regulation), but are not products, seafood salads, seafood soups and covered in this chapter. sauces, and hot-smoked fish. CHAPTER 16: Pathogenic Bacteria Survival Through Cooking or Pasteurization 315 • Goal of pasteurization (38°F (3.3°C)) are not uncommon. Therefore, Selection of the target pathogen is critical to refrigeration alone cannot be relied upon for the effectiveness of pasteurization. You should control of the C. botulinum hazard. When consider the potential that C. botulinum type freezing is relied upon to control the growth of E or non-proteolytic types B and F will survive C. botulinum type E and non-proteolytic types B the pasteurization process and grow under and F, controls should be in place to ensure that normal storage conditions or moderate abuse the product is labeled with instructions that it be conditions. This is of particular concern if the kept frozen throughout distribution. product is reduced oxygen packaged (e.g., For pasteurization processes that target C. vacuum packaged or modified atmosphere botulinum type E and non-proteolytic types B and packaged), does not contain a barrier that is F, generally a reduction of six orders of magnitude sufficient to prevent growth and toxin formation (six logarithms, e.g., from 103 to 10 -3) in the level by this pathogen, is not equipped with a time of contamination is suitable. This is called a 6D and temperature integrator, and is stored or process. However, lower degrees of destruction distributed refrigerated (not frozen). In such may be acceptable if supported by a scientific products, you should ordinarily select C. study of the normal levels in the food before botulinum type E and non-proteolytic types pasteurization. It is also possible that higher levels B and F as the target pathogen. For example, of destruction may be necessary in some foods, if vacuum-packaged lobster meat that is pasteurized especially high initial levels of the target pathogen to kill L. monocytogenes, but not C. botulinum are anticipated. Table A-4 (Appendix 4) provides type E or non-proteolytic types B and F, and 6D process times for a range of pasteurization is not equipped with a Time-Temperature temperatures, with C. botulinum type B (the Indicator should be frozen to prevent growth most heat resistant form of non-proteolytic C. and toxin formation by C. botulinum type E botulinum) as the target pathogen. The lethal rates and non-proteolytic types B and F, and should and process times provided in the table may not be labeled to be held frozen and to be thawed be sufficient for the destruction of C. botulinum under refrigeration immediately before use (e.g., type E and non-proteolytic types B and F in “Important, keep frozen until used, thaw under dungeness crabmeat, because of the potential that refrigeration immediately before use”). naturally occurring substances, such as lysozyme, If the product is not reduced oxygen packaged, may enable the pathogen to more easily recover or contains a barrier that is sufficient to prevent after heat damage. the growth and toxin formation by C. botulinum Examples of properly pasteurized products are type E or non-proteolytic types B and F, or fish and fishery products generally (e.g., surimi­ is equipped with a time and temperature based products, soups, or sauces) pasteurized integrator, or is distributed frozen, then selection to a minimum cumulative total lethality of F194°F of another target pathogen may be appropriate. (F90°C) = 10 minutes, where z = 12.6°F (7°C) for L. monocytogenes may be selected as the target temperatures less than 194°F (90°C) and z = 18°F pathogen for pasteurization of this type of (10°C) for temperatures above 194°F (90°C); blue product because it is the most resistant bacterial crabmeat pasteurized to a minimum cumulative pathogen of public health concern that is total lethality of F185°F (F85°C) = 31 minutes, where z reasonably likely to be present. = 16°F (9°C); and dungeness crabmeat pasteurized Surveys of retail display cases and home to a minimum cumulative total lethality of F194°F refrigerators indicate that temperatures above the (F90°C) = 57 minutes, where z = 15.5°F (8.6°C). minimum growth temperature of C. botulinum Equivalent processes at different temperatures can type E and non-proteolytic types B and F be calculated using the z values provided. CHAPTER 16: Pathogenic Bacteria Survival Through Cooking or Pasteurization 316 forming unit (CFU)/g and that approximately 91% EXAMPLES OF PROPERLY are contaminated at less than 1 CFU/g. Less than PASTEURIZED PRODUCTS 1% of raw seafood are contaminated at levels MINIMUM CUMULATIVE 3 PRODUCT Z VALUE greater than 10 CFU/g and none at levels greater TOTAL LETHALITY than 106 CFU/g. FDA’s limit for L. monocytogenes Fish and F194°F (F90°C) = 10 minutes 12.6°F (7°C), for fishery temperatures in ready-to-eat products, nondetectable, products less than 194°F corresponds to a level of less than 1 CFU/25g. generally (90°C) (e.g., surimi­ Table A-3 (Appendix 4) provides 6D process based 18°F (10°C) for products, temperatures times for a range of pasteurization temperatures, soups, or above 194°F (90°C) with L. monocytogenes as the target pathogen. sauces) Lower degrees of destruction may be acceptable Blue F (F ) = 31 minutes 16°F (9°C) 185°F 85°C if supported by a scientific study of the normal crabmeat levels in the food before pasteurization. It is also Dungeness F194°F (F90°C) = 57 minutes 15.5°F (8.6°C) crabmeat possible that higher degrees of destruction may be necessary in some foods if especially high In some pasteurized surimi-based products, salt, initial levels are anticipated. in combination with a milder heat pasteurization Products that are pasteurized in the finished process in the finished product container, works product container are at risk for recontamination to prevent growth and toxin formation by C. after pasteurization. Controls, such as container botulinum type E and non-proteolytic types B seal integrity and protection from contaminated and F. An example of a properly pasteurized cooling water, are critical to the safety of these surimi-based product in which 2.4% water phase products and are covered in Chapter 18.