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Recommendations Specific recommendations developed on the basis of discussions in each of the chapters and sections of this book are summarized below. INTRODUCTION (CHAPTER 1) It is recommended that those who are concerned with the use of mi- crobiological criteria take cognizance of the following: 1. With a few exceptions, i.e., canned products receiving a heat process sufficiently severe to render them sterile, microorganisms are associated with foods. Among these are microorganisms capable of causing spoilage, others capable of causing illness if they are not destroyed before the food is consumed, and still others that may produce illness-causing toxins if they multiply in a food before its consumption. In addition, the presence and growth of microorganisms may be associated with the production of some foods, and their presence in the product, sometimes in large numbers, is indicative of desired quality for these foods. 2. Foods may be segregated into two categories with respect to their stability, i.e., those that are shelf-stable and those that are perishable. a. Shelf-stable foods are not necessarily sterile; in fact most of them are not. Their distinguishing characteristic is that some attribute or com- bination of attributes prevents the growth of microorganisms, e.g., pH, water activity (aw), preservatives, etc. The microbiological spoilage of a food purported to be shelf-stable is an unexpected event that generally indicates improper processing (as for example underprocessing of canned foods) or improper handling (as for example the wetting of a dried product). b. Perishable foods have a limited shelf-life and their microbio 15
16 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA logical spoilage is an expected event. Generally speaking, perishable foods are selective environments. As a consequence the microbial flora that causes spoilage of such foods is characteristic. It follows, as a result, that the manifestations of spoilage of various perishable foods are likewise characteristic, and this constitutes a consumer safeguard. 3. Safety and "microbiological quality," as measured by the numbers of microorganisms present in a food, are not necessarily directly related. a. Shelf-stable foods may contain low numbers of microorganisms and yet present a health hazard. For example, nonfat dried milk may have a very low aerobic plate count (APC) and be free of coagulase-positive staphylococci, yet contain Staphylococcus enterotoxin. Chocolate candy may have a low APC, yet contain salmonellae. Roasted peanuts may be virtually free of microorganisms, yet contain dangerously high levels of mycotoxin. b. A perishable food may have an exceedingly high APC yet not constitute a health hazard. As a corollary, a perishable food may have a low APC, yet constitute a health hazard. DEFINITIONS, PURPOSES, AND NEEDS FOR MICROBIOLOGICAL CRITERIA (CHAPTER 2) 1. Microbiological standards should be considered only when: a. there is evidence to indicate that a problem exists between a food and outbreaks of foodborne disease and that the standard will alleviate the problem; b. exceeding the limits is evidence that the food contains decom- posed ingredients, and/or is evidence of preparation, packaging, or storage of the food under grossly poor conditions; or c. there is no jurisdiction over processing and distribution practices, such as with certain imported foods, and the standard would eliminate a health hazard and/or reject products produced under questionable condi- tions. Wherever a product poses a direct hazard to health, an implied standard exists (see Chapter 1, page 52, note 3~. 2. Microbiological guidelines should be used as alerting mechanisms to signal when microbiological conditions during processing, distribution, and marketing of foods are not within the normal range. 3. Purchase specifications should be based on relevant background data and should fill a need. Microbiological quality standards, such as those recently proposed by the Food and Drug Administration (FDA) for certain frozen seafoods, are
RECOMMENDATIONS 17 not recommended since they are not related to organoleptic quality and since guidelines can serve to monitor good manufacturing and distribution practices. SELECTION OF FOODS FOR CRITERIA RELATED TO SAFETY (CHAPTER 3) It is recommended that the following factors provide the primary bases for deciding whether a microbiological criterion for a given food would or would not serve a useful purpose: (1) epidemiological evidence that the food is a significant vehicle for the transmission of foodborne disease, (2) the susceptibility of the food to microbial contaminations, (3) the opportunities for survival of contaminants in the foods, (4) the likelihood that growth of contaminants would occur at some point during manufac- ture, storage, distribution, and under conditions preparatory to serving, (5) the treatment to which a food may be subjected just prior to its serving, and (6) the susceptibility of probable consumers to infectious or toxic agents. SELECTION OF PATHOGENS AS COMPONENTS OF MICROBIOLOGICAL CRITERIA (CHAPTER 4) A pathogen, to be eligible for consideration as a component of a mi- crobiological criterion, must likely be found in a particular food or in- gredient with a consequence serious enough to cause concern. Such a food is considered sensitive to the presence of the particular pathogen. Based on current information, the rationale for determining whether a pathogen or toxin of concern should be designated in a microbiological criterion for a food sensitive to it is given in Chapter 4 and provides the bases for the following recommendations: Pathogens Clostridium botulinum 1. C. botulinum should not be designated in microbiological criteria for application in the routine surveillance of sensitive foods. 2. In the course of epidemiological investigations of botulism out- breaks, suspect foods should be examined for the presence of C. botulinum and/or its toxins. 3. For assurance of the safety of low-acid and acidified low-acid canned foods from the botulism hazard, industry and official agencies should rely upon fail-safe mechanisms to be certain that control of heat processing,
18 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA pH, and aw have been adequately accomplished and that container integrity has been maintained. Shigella 1. Microbiological criteria for Shigella should not be established for routine surveillance of foods. Methods of analysis are too complicated and insensitive to be practical for this purpose, but they are useful in the course of epidemiological investigations of outbreaks to examine suspect foods for the presence of Shigella. 2. Presence of Shigella in foods that are not heated before consumption should cause the food to be rejected. Vibrio cholerae 1. Microbiological criteria for V. cholerae should not be established for routine surveillance of foods. 2. Strict adherence to provisions of the National Shellfish Sanitation Program (NSSP) should be relied upon as the principal means of preventing raw oysters, mussels, and clams from becoming contaminated with V. cholerae and serving as vehicles for its transmission to consumers. 3. Adequate heat treatment of crabmeat before eating and use of good sanitary practices in handling crabmeat and other sensitive foods before and after heat treatment should prevail. Brucelia and Mycobactertum bovis 1. Prevention of milkborne brucellosis and tuberculosis is dependent upon pasteurization of milk supplies and adherence to the provisions of the state/federal brucellosis and tuberculosis eradication programs for cat- tle. As part of these programs serological tests are used to detect Brucella and Mycobacterium bovis infections in cattle. In this context, microbio- logical criteria for these organisms are feasible and should continue to be applied. 2. Suspect tuberculosis lesions found during carcass inspection at slaughter are routinely cultured for Mycobacterium. In this sense a microbiological criterion is feasible and should continue to be applied. Viruses 1. Microbiological criteria for viruses in foods should not be established for routine surveillance of foods. At present methods of analysis are impractical for that purpose.
RECOMMENDATIONS 19 2. Laboratories capable of analyzing foods for viruses should be en- couraged to examine suspect foods for them during the course of epide- miological investigations of suspected viral foodborne outbreaks. Paralytic Shellfish Poison (PSP) A microbiological standard for PSP is applied regularly to samples of shellfish from growing waters and in accordance with the National Shell- fish Sanitation Program. Routine application of the standard to shellfish at wholesale and retail markets would not be an effective control measure and should not be used for this purpose. Ciguatera Toxin ts) There are no federal or state surveillance programs for preventing the occurrence of ciguatera fish poisoning other than some educational effort to emphasize the hazard of toxic fish due to the presence of this toxinks). Until the factors responsible for toxic concentrations of the toxints) in fish are clarified and specific and practical assay methods for the toxinfs) become available, microbiological criteria would have no meaning and should not be established. Mycotoxins The FDA has set standards (tolerance levels) for aflatoxin Be and af- latoxin Me for sensitive foods. These criteria have been effective in pre- venting toxic foods from reaching the public and susceptible animals and should continue to be applied. Salmonella 1. Microbiological criteria for Salmonella are commonly applied by industry and official agencies. They have been effective in preventing contaminated foods from reaching the market and should continue to be applied to sensitive foods and feeds. 2. FDA should be encouraged to abandon the bases currently used for establishing Salmonella sampling plans and to return to the system that was used prior to publication of the fourth edition of the Bacteriological Analytical Manual (BAM) (for further discussion refer to Appendix A-I). Pathogenic Escherichia cold (PEC) 1. Procedures for detection and enumeration of pathogenic E. cold are at present not practical for use in routine food surveillance programs.
20 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA Microbiological criteria specifically for these E. cold biotypes would be impractical and should not be established for this purpose. 2. In the course of investigations of outbreaks, suspect foods should be examined for the presence of PEC. (see also Chapter 5.) Streptococcus pyogenes 1. Because of the lack of a practical method for detection and enu- meration of S. pyogenes in foods and the infrequency of foodborne out- breaks caused by this organism, a microbiological criterion would not be useful and should not be established. 2. Pasteurization of milk, adequate heating, and sanitary handling of sensitive foods should be relied upon for prevention of foodborne S. pyogenes infections. Staphylococcus aureus Microbiological criteria for S. aureus are feasible and should be estab- lished and applied to appropriate foods to indicate potential presence of enterotoxin or to indicate faulty sanitary and/or production practices. Clostridium perfringens 1. The presence of low numbers of C. perfringens in many foods usually is unrelated to faulty sanitary practices. Only large numbers in a food would be cause for concern. Microbiological criteria for use in routine surveillance programs would not contribute significantly to prevention of outbreaks of C. perfringens enteritis and should not be established for that purpose. 2. Suspect foods from outbreaks should be examined for this organism. 3. When temperature abuse of sensitive foods has occurred or is sus- pected, analysis for presence of alpha toxin (indicator of extensive growth of C. perfringens) should be made. In this sense a microbiological criterion for alpha toxin is useful. Bacillus cereus 1. During investigation of outbreaks in which symptoms observed are similar to those of C. perfringens or S. aureus, the suspect foods should also be examined for B. cereus. 2. Low numbers of B. cereus are found in many foods, but only large numbers are cause for concern. It is unlikely that microbiological criteria
RECOMMENDATIONS 21 for purposes of routine surveillance of foods would be justified. At present, criteria for that purpose should not be established. Vibrio parahaemolyticus 1. Microbiological criteria for use in routine surveillance of seafoods are not practical at this time and should not be established. 2. Methods for identifying and enumerating pathogenic strains are suf- ficient for examination of seafoods or seafood products that may be im- plicated in outbreaks. Examination of such foods for V. parahaemolyticus always should be made. Coxiella burnetii Routine use of the agglutination test for the presence of C. burnetii in milk supplies available to the public would not be useful in preventing C. burnetii infections in man and should not be used for this purpose. Histamine The practice of much of the fisheries industry to examine routinely susceptible fish for histamine content should be expanded to all of the industry as a means of preventing deteriorated and/or toxic fish from reaching consumers. Yersinia enterocolitica Owing to the low incidence of outbreaks caused by Y. enterocolitica and the complexities of quantitative recovery methods for pathogenic strains, microbiological criteria for this organism would be of little value in routine surveillance programs and therefore should not be established until changes in this situation indicate otherwise. Campylobacter fetus subsp. jejuni Microbiological criteria for routine application to foods would not be a significant preventive measure for foodborne campylobacteriosis and should not be established at present.
22 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA Tr~chinella spiralis In view of the procedures specified by USDA for, and the almost universal practice of, cooking raw pork, routine examination of meat for larvae to control trichinellosis is not recommended. General Actions Research Methods should be developed for more rapid detection and quantitative enumeration of those bacterial pathogens and of those viruses, toxic sub- stances, and parasites that are significant causes of foodborne illness. Federal agencies concerned with control of food safety and quality should provide financial support that will foster increased research on micro- biological methods for the examination of food. Morbidity and Mortality Weekly Reports The benefits derived from the reporting of foodborne disease outbreaks to the Centers for Disease Control (CDC) are many. One of these benefits has been the wide distribution, without cost to the recipient, of reports of these reported outbreaks through CDC's weekly morbidity and mortality reports. By this means personnel of industry, regulatory agencies, uni- versities, and other organizations were kept abreast of the occurrence of outbreaks, the causes of these outbreaks, and often the control measures that were instituted. These reports played a significant role in drawing attention to the ever-present problem of foodborne illness and the need for preventive measures. Accordingly, the CDC should reconsider its decision to curtail free distribution of the Morbidity and Mortality Weekly Report. SELECTION OF INDICATOR ORGANISMS AND AGENTS AS COMPONENTS OF MICROBIOLOGICAL CRITERIA (CHAPTER 5) Aerobic Plate Count Because generalizations of the relationship between APCs and sensory quality of foods are not possible and little direct relationship exists between APCs and safety, APCs generally should not be specified in microbio- logical criteria for these purposes. They can, however, indicate microbial survival of processes or growth at critical control points.
RECOMMENDATIONS 23 Direct Microscopic Count Because of the inherent characteristics of the method, microbiological criteria involving direct microscopic count limits should be restricted to those situations where high microbial populations (viable, nonviable, or both) are expected and where information on the microbial history of the food (such as dried milk or eggs) may be useful. Microscopic Mold Counts The use of these microscopic mold counts (Howard mold count, rot fragment count) as components of microbiological criteria to detect intro- duction of decayed tissue of fruits and vegetables into processed product and as an index of manufacturing practices should be continued but re- evaluated in terms of the effect of certain processing practices. Machinery Mold Although Geotrichum candidum has been used to evaluate sanitation in fruit and vegetable processing plants, additional studies are recommended to relate filament counts to modern processing practices. Yeast and Mold Counts Application of yeast and mold counts is often related to special con- ditions in a food such as low pH and/or low aw, which are not conducive for bacterial growth but in which many fungi are capable of proliferating. Microbiological criteria for yeasts and molds are useful under such con- ditions and should be applied to sensitive foods, e.g., sugars, fruit bev- erages, and soft drinks. Heat-Resistant Molds Limits for heat-resistant molds such as Byssochlamys fulva and Asper- gillus fishe)i are applicable primarily to thermally processed fruits and fruit juices. Microbiological guidelines for application by industry should be encouraged. Thermophilic Spore Count Thermophilic spore counts have been applied extensively in industry for ingredients such as sugars, starches, flour, spices, and cocoa. Their
24 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA use as components of microbiological criteria for food ingredients to be used in low-acid canned foods should be continued. Dye or Indicator Reduction Time Technological advances in the sanitary production of raw milk have outstripped the usefulness of dye reduction tests for grading this product. More sensitive methods are available and use of dye reduction tests should be discouraged. Dye reduction tests have little merit for the evaluation of other foods such as meat, fish, poultry, vegetables and fruits. pH Measurements of pH are important to monitor acid production at critical control points in the processing of appropriate foods, particularly dry and semidry fermented sausages, fermented milks, and cheese, and to deter- mine equilibrium pH of acidified canned foods, mayonnaise, and salad dressings. Trimethylamine and Total Volatile Nitrogen (TMA and TVN) Although TMA and/or TVN values are often closely related to microbial degradation of certain species of fish, their use for detection of spoilage is subject to severe limitations. At present they should not be used in regulatory criteria for seafoods in the United States. Research should be encouraged to evaluate relationships among these parameters and micro- biological deterioration and sensory characteristics of economically im- portant fish species in the United States. Indole The indole content is a useful index to detect certain types of microbial decomposition that occurred in imported canned/cooked frozen shrimp prior to heating. The indole level is also a useful index to evaluate the acceptability of imported frozen raw shrimp, provided that it is not used as the sole indicator. In this case it should be of value to assess prior temperature abuse when used in conjunction with other quality tests such as organoleptic examination. Ethanol Current information indicates that the ethanol content of salmon may serve as a useful index of microbial decomposition and therefore may
RECOMMENDATIONS 25 have useful application as a component of a criterion to evaluate accept- ability. Continued research should be encouraged to further evaluate this relationship. Diacetyl The diacetyl content should be applicable as a parameter to monitor the sanitary condition of fruit processing. Histamine The histamine content should be applied as part of a microbiological criterion for scombroid fish. The Association of Official Analytical Chem- ists (AOAC) fluorometric method should be applied where sophisticated laboratory equipment and technicians are available. If collaborative tests indicate that a recently developed rapid screening test has satisfactory sensitivity, it should become a valuable tool to monitor incoming scom- broid fish. LLT and ATP Although tests such as the Limulus amoebocyte lysate test (LLT) and the test for adenosine triphosphate (ATP) are not yet developed where they can be used routinely in the microbiological evaluation of foods, further research on these and other rapid tests is recommended. Staphylococci S. aureus counts are applicable as a component of microbiological criteria to indicate the potential presence of enterotoxin and lack of sanitary handling of sensitive foods. The AOAC MPN method should be replaced by the direct plating method because the former is inhibitory to injured cells and offers no advantage with respect to method sensitivity. Escherichia cold E. cold is the best indicator of fecal contamination presently available. Microbiological criteria involving E. cold should be applied to sensitive foods as indicators of fecal contamination. In the interest of more rapid and sensitive detection and enumeration of E. coli, the direct plating method (see E. cold section in text) should be further evaluated for ap- plication to a broad spectrum of foods.
26 EVALUATION OF THE ROLE OF MlCROBlOLOGICAL CRITERIA Fecal Coliforms A fecal coliform standard is currently used to evaluate the sanitary condition of shellfish growing waters. Its use has been successful and should be continued. However, since the best indicator of fecal contam- ination is E. coli, the direct plating method should be further evaluated for use in this program. Enterococci The significance, accuracy, and precision of the methodology is limited and is poorly correlated with safety or sanitary quality characteristics of foods. Therefore microbiological criteria for enterococci should not be applied. Pseudomonas aeruginosa The value of P. aeruginosa as an index of safety of bottled water should be further evaluated and accurate methods for the detection and enumer- ation of this organism should be developed. Coliform Bacteria Coliform counts are applicable in microbiological criteria for many foods to indicate post-heat processing contamination. However, E. cold or a fecal connotation of E. cold should not be linked categorically to any food in which coliforms are found. Enterobacteriaceae Enterobacteriaceae counts and coliform counts are generally used for the same purpose. The former has not been used to any appreciable extent in the United States, although it is commonly used in Europe. Because the advantages of the Enterobacteriaceae count over the coliform count are not substantial, the latter should be the method of choice for use in microbiological criteria in the United States. T hermo nucle as e T est (T Nase ) The TNase test should be applicable in microbiological criteria for the purpose of screening foods such as certain cheeses and sausages for ex- tensive growth of 5. aureus and presence of enterotoxinks).
RECOMMENDATIONS 27 Aflatoxin Detection by Ultraviolet Light The use of ultraviolet light as a screening test for detection of aflatoxin in moldy corn and other grains has been successful and should be con- tinued. Phosphatase Test Although limited in application, this test is useful in criteria for certain milk and milk products to detect underpasteurization. Its use in the dairy industry should be continued and expanded. CONSIDERATIONS OF SAMPLING ASSOCIATED WITH A CRITERION (CHAPTER 6) 1. The sampling procedure and decision criteria are essential parts of a microbiological criterion and should be based on sound statistical con- cepts. 2. The concept of relating the stringency of a sampling plan to the degree of hazard of the food is a meaningful way of making such a selection. 3. Where attributes sampling plans are applicable, the ICMSF 2- and 3-class plans are recommended for microbiological criteria for foods. 4. Further studies are recommended to evaluate the applicability of variables sampling plans to microbiological criteria for foods. CONSIDERATION OF DECISION (ACTION) TO BE TAKEN WHEN A CRITERION (LIMIT) IS EXCEEDED (CHAPTER 7) Assuming that microbiological criteria have been established in accor- dance with the principles set forth in Chapter 2, it is recommended that individuals responsible for the decision--making process take cognizance of the following: 1. When the limit of a criterion (whether it be a standard, a guideline, or a specification) is exceeded, it should trigger action on the part of the responsible authority. The nature of the action depends upon the purpose for which the criterion was established, but if the criterion was established according to the principles set forth in Chapter 2, then failure to meet the established limits set by it should signal decisive action. 2. If analytical results indicate a direct health hazard, it must be decided if the product should be destroyed or if it can be diverted to some use that obviates the hazard.
28 EVALUATION OF TI1E ROLE OF MICROBIOLOGICAL CRITERIA 3. If analytical results indicate the potential for the development of a direct health hazard if the product is mishandled, it must be determined whether or not the product can be diverted into channels where its safe handling can be assured and thus the potential for developing a hazard obviated. 4. If analytical results indicate that the product was not produced under conditions assuring safety, the action taken should vary with the product so as to obviate any potential hazard. 5. If analytical results indicate a raw material may adversely affect the shelf-life of a finished product, the processor must determine whether or not to use the raw material. 6. If an analytical result indicates that a critical control point is not under control, this should trigger immediate action by the food processor. CURRENT STATUS OF MICROBIOLOGICAL CRITERIA AND LEGISLATIVE BASES (CHAPTER 8) This chapter is a status report; therefore, recommendations are not appropriate. APPLICATION OF MICROBIOLOGICAL CRITERIA TO FOODS AND FOOD INGREDIENTS (CHAPTER 9) Dairy Products 1 . The U. S. Department of Agriculture (USDA) should consider amending its recommended bacterial count standard for Grade 2 milk for manufacturing purposes to more adequately reflect use of good sanitary and other handling practices during production, transportation, and storage of raw milk before processing. 2. The current USDA program for Salmonella surveillance of do- mestically produced dried milk products should be strengthened by (a) collecting samples at least monthly rather than quarterly, (b) using sam- pling plans consistent with recommendations of the NAS/NRC Salmonella report, and (c) drawing samples at the time of successive surveys from each dryer located in a plant having more than one dryer rather than from only one as is the current practice. 3. The current practice of most of the dried milk industry to test products for Salmonella should be applied by all manufacturers of dried milk, dried cheese, and dried blends composed principally of dairy products. Such
RECOMMENDATIONS 29 testing should be appropriately monitored through cooperative effort of federal and state regulatory agencies. 4. Programs for Salmonella surveillance of dried milk products offered at import should be continued. These programs should be reviewed pe- riodically to ascertain that sampling plans, including methods used, are consistent with the hazards presented and in accord with current devel- opments in methodology and with appropriate statistical concepts. 5. Manufacturers of cheese varieties susceptible to the development of large numbers of Staphylococcus should be encouraged to (a) routinely monitor critical control points for presence or indications of staphylococcal growth, and (b) test all such finished cheese for S. aureus or thermonu- clease or both if abnormal lactic culture activity occurred during manu- facture or if other indications of conditions that might lead to extensive staphylococcal growth were encountered. 6. Routine testing of domestically produced cheese by regulatory agen- cies is not recommended; however, industry testing programs should be monitored by these agencies. 7. FDA should routinely test all susceptible cheese varieties offered at import for presence of thermonuclease. Positive lots should be rejected. 8. FDA should undertake jointly with the French government and in- dustry a comprehensive study of the problems of pathogenic E. cold in imported soft cheese with the objective of further reducing the hazard of pathogenic E. cold in susceptible varieties. The work should include an- alytical surveys of cheese offered at import as well as studies at point of production. 9. Regulatory agencies, industry, university extension departments, and other organizations concerned with the public health should (a) more actively emphasize that pasteurization is an essential process in providing milk free of disease-causing microorganisms, (b) cooperatively develop and apply with renewed vigor programs that will discourage consumption of raw milk, and (c) aggressively work toward development of legislation that will declare the sale of raw milk illegal in the United States. 10. The ability of S. aureus to grow in whipped butter has been dem- onstrated. Regulatory agencies should encourage manufacturers of whipped butter to routinely apply in-plant guidelines for the APC and S. aureus at critical control points of manufacture. 11. Whey cream as an ingredient in butter manufacture (or any for- mulated product) should be tested for staphylococcal thermonuclease be- fore use; product showing a positive test should either not be used or be further tested to confirm presence or absence of staphylococcal entero- toxins.
30 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA Raw Meats 1. To produce raw red meat with optimum shelf-life, critical control points such as slaughtering-dressing practices, sanitary condition of equip- ment and utensils, and control of refrigeration temperature should be monitored carefully. Microbiological guidelines are applicable to monitor some of these critical control points. 2. To achieve optimum shelf-life of raw meats, the HACCP concept should be extended to include retail outlets, food service establishments, and homes, particularly as it pertains to handling practices and maintenance of adequate refrigeration. 3. Microbiological standards for raw meats are not recommended since they will prevent neither spoilage nor foodborne illness. 4. Microbiological criteria containing limits for pathogens in raw meats are not recommended. 5. To reduce the health hazards from raw meats the following should prevail: a. recognition that small numbers of pathogens may be present on raw meats; b. strict adherence to good food preparation practices; c. application of new or alternate production and processing prac- tices that reduce the incidence of pathogens; d. more effective education on food-handling practices of food plant personnel, food service operators, and homemakers; e. increased emphasis on inspection of food service establishments using the HACCP approach. 6. Present inspections of food-processing facilities and operations by regulatory agencies such as the USDA should be made more cost-effective by application of the HACCP concept. Processed Meats 1. Microbiological guidelines for raw ground beef and for perishable raw salted and salted cured meat should be applied at the processing level to assess the microbiological condition of the raw materials used, the effectiveness of equipment sanitation and the microbiological condition of the freshly processed product. Application of microbiological criteria to these products after they have entered trade channels is of little value. 2. The processor should apply microbiological criteria for Salmonella in evaluating cooked roast beef at the processing facility before it is shipped to distribution channels. 3. Microbiological control of shelf-stable raw salted and salted cured meats should be exercised by control of critical control points such as
RECOMMENDATIONS 31 temperature during curing and humidity during the postcuring drying pe- riod. 4. In the processing and handling of cooked cured meats, microbio- logical guidelines should be applied to evaluate the quality of raw ma- terials, equipment sanitation, and condition of finished product. Microbiological criteria for products that have entered retail channels are inappropriate. 5. Application of criteria involving 5. aureus, thermonuclease, and/or enterotoxin should be applied to ascertain that proper acid formation during production of fermented sausages has taken place. 6. Microbiological guidelines (APC) should be applied to dried meats as a means of assuring the adequacy of moisture control during the drying process. Criteria for pathogens should be appropriately applied depending upon the ultimate use of the product. Raw (Eviscerated, Ready-To-Cook) Poultry Recommendations regarding raw poultry are focused on two objectives, namely to reduce the risk of association of poultry, directly or indirectly, with foodborne disease and to produce a product with optimum quality characteristics and shelf-life. 1. A HACCP system tailored to the specific processing conditions and careful monitoring of critical control points such as sanitary condition of equipment, employee practices, carcass washing, cooling, and storage procedures should be applied to obtain optimum quality characteristics and shelf-life of freshly processed carcasses and to keep the number of pathogens at the lowest possible level. 2. Microbiological guidelines that are part of such HACCP programs should include (a) periodic evaluation of equipment surfaces to check cleaning and sanitation procedures, and (b) evaluation of processing prac- tices by examination (aerobic plate count and coliforms) of freshly pro- cessed carcasses. 3. To increase shelf-life of refrigerated poultry, refrigerated storage in vacuum packages or in modified gaseous atmospheres is being considered. Research directed toward determination of the effect of these practices on safety and shelf-life of raw poultry should be intensified. 4. Until infection and contamination of birds on the farm are reduced effectively and/or until a method of decontamination is routinely applied to packaged carcasses, microbiological criteria for raw poultry with limits for pathogens, e.g., Salmonella, are considered impractical and should not be applied. 5. Recommendations for the reduction or eradication of Salmonella in
32 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA raw poultry given in this report (Chapter 9, part D) and in the NRC report on the Salmonella problem are considered of the highest priority in efforts to reduce the health hazard from consumption of cooked poultry. 6. Because raw poultry may contain pathogens, food service personnel and homemakers should adhere strictly to good food-handling and prep- aration practices. 7. Additional studies are recommended to evaluate the role of newly emerging pathogens associated with poultry such as C. fetus subsp. jejuni, including practical methods for detection, enumeration, and control of these organisms. Processed Poultry Products 1. To obtain safety and optimum shelf-life of processed poultry, a HACCP system should be developed for each group of products. 2. Shelf-life and quality characteristics of refrigerated tray-pack prod- ucts should be controlled by monitoring critical control points such as the microbiological condition of carcasses used, sanitary handling of the prod- uct during cut-up operations, sanitary condition of equipment, and time- temperature profile of product during processing and storage. Microbio- logical guidelines involving APC (swab, rinse, or other simple procedures) should be applied at critical control points to evaluate the sanitary condition of poultry carcasses and processing equipment. 3. To obtain safe ready-to-eat poultry, strict adherence to recommended food-handling and preparation practices such as proper cooking, chilling, refrigerated storage, hot-holding, reheating, and avoidance of cross-con- tamination should be continually emphasized. 4. Safety and shelf-life of perishable cooked further-processed poultry products should be controlled by careful monitoring of critical control points such as microbiological condition of the carcasses, deboning and trimming operations, sanitary condition of equipment, product flow, time- temperature profile during processing, cooking, chilling, slicing, pack- aging, and storage conditions. Microbiological guidelines should be ap- plied for: a. carcasses (APC), particularly if they were from other sources; b. checking sanitary condition of equipment (APC by swab, direct contact, or other simple methods) particularly in areas where cooked products are handled; c. packaged products (APC, S. aureus, coliforms, Salmonella). 5. Studies are recommended to improve the design and layout of pro- cessing equipment and handling operations to reduce opportunity for post- heat contamination of cooked products.
RECOMMENDATIONS 33 6. Poultry potpies, particularly heated pies, should not be subjected to temperature abuse; otherwise they may become a health hazard (botulism, C. perfringens enteritis). Microbiological criteria, however, should not be used to monitor temperature abuse of potpies. Eggs and Egg Products 1. It is recommended that the USDA adopt the sampling plans suggested by the National Research Council Committee on Salmonella (NRC, An Evaluation of the Salmonella Problem, 19691. Depending upon the ulti- mate use of the product, egg products should be classified as Category I or Category II products. 2. The sampling plans utilized by the USDA for confirmation and surveillance are even less stringent than those employed for certification. It is recommended that in connection with these programs Category I or Category II sampling plans be utilized. 3. The USDA provides for retesting of lots found positive for Sal- monella, though plants with known Salmonella problems are not permitted to resample. It is recommended that the practice be reviewed in terms of the "resampling syndrome" discussed in Chapter 6. 4. It is recommended that the sampling frequency, as required by the USDA (see Figure 9-2, Chapter 9, part F), be critically reviewed. 5. The USDA instructions (see Chapter 9, part F) state that no rigid or set sampling pattern is to be followed in connection with surveillance sampling. It is recommended that this "random approach" to sampling be reviewed in terms of its consistency with the principles of statistical quality control. Fish, Molluscs, and Crustaceans 1. Microbiological standards (National Shellfish Sanitation Program) for shellfish growing waters and for raw shellfish should be updated as new information becomes available on more effective test procedures to monitor contamination of growing waters and shellfish. This is particularly true with respect to the presence of viruses in waters and shellfish that can cause human illness. 2. Since rapid, direct plating methods have recently become available to test water and shellfish directly for E. colt, the use of E. cold instead of coliforms or fecal coliforms as part of microbiological criteria for shellfish and shellfish growing waters should be evaluated. 3. Regulatory agencies and industry should direct efforts to determine the potential hazards of packaging raw seafoods and holding them under
34 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA refrigeration in vacuum or in modified gaseous atmospheres specifically relative to opportunities for growth and toxin production by C. botulinum. This packaging/storage method is not recommended for raw seafoods until the safety of this practice is validated. 4. Additional research efforts are recommended to evaluate the signif- icance of Vibrio species associated with diseases in humans, specifically to: a. detect and enumerate more effectively pathogenic strains of V. parahaemolyticus; b. determine the distribution of V. cholerae (01 and non-01) in seafoods and the effect of processing, storage, and food preparation prac- tices on survival and/or growth of these species; c. evaluate the potential hazards of V. mimicus, V. fluvialis, V. fuluificus, and V. hollisae in raw and processed seafoods. 5. Scombroid poisoning, ciguatera, and paralytic shellfish poisoning (PSP) are prominent foodborne diseases associated with the consumption of fish and shellfish. Although knowledge about these diseases has in- creased greatly in recent years, increased research effort should be directed to the nature of the toxins, toxicity levels to humans and test methods, particularly practical methods, to detect and quantitate toxins in fish and shellfish. 6. Application of HACCP systems is recommended to assure safety and wholesomeness of fish and fishery products. Within this system, microbiological guidelines should be implemented whenever needed to monitor critical control points. For fresh raw products, monitoring of critical control points should consist primarily of inspection of incoming materials for odor and appearance, control of temperature (refrigeration or freezing), equipment sanitation, and employee handling. Additional concerns that should be considered include: for mulluscan shellfish, the fecal coliform count of growing waters and of the wholesale product and the presence and levels of saxitoxin and related toxins; for processed tuna, the level of histamine. For cooked ready-to-eat products, microbiological guidelines for fin- ished products that include APC, E. colt, and S. aureus should be im- plemented. 7. Microbiological criteria for fish set by state and local regulatory agencies are generally not based on sound background data and are im- practical from the standpoint of compliance or enforcement. In those instances where there is a need for a microbiological criterion, it should be developed from properly designed and executed studies. 8. Microbiological quality standards recommended by FDA for frozen
RECOMMENDATIONS 35 crab cakes, frozen fish cakes, and frozen fish sticks should not be accepted by state and local regulatory agencies as standards since these products constitute neither a health hazard nor a serious quality problem. Fruits and Vegetables 1. Microbiological standards are not recommended for raw and pro- cessed fruits and vegetables. In general these foods have had an excellent public health record, and in most instances where they have been the vehicle for foodborne illnesses, standards would not have prevented the problem. 2. It is recommended that guidelines, based on sound data, be used for assessing manufacturing practices in the processing of dried and frozen fruits and vegetables. Where appropriate, aerobic plate counts should be used for evaluating low-acid vegetables while fruits should be cultured for aciduric microorganisms such as yeasts and lactic acid bacteria. There is little evidence that routine tests for coliforms serve any useful purpose. They usually are a part of the normal processing-line microflora. The routine testing for foodborne pathogenic bacteria is not recommended since most samples would be negative for infectious organisms and would yield only low populations of toxigenic species. 3. Microscopic mold counts (Howard, rot fragment, and G. candidum) can be useful for assessing the wholesomeness of raw fruits and vegetables and the sanitary status of cannery lines. However, additional research to relate modern processing conditions to the levels of filaments is recom- mended. Fruit Beverages 1. Microbiological standards are not recommended for fruit juice bev- erages since they have rarely been responsible for foodborne illnesses. 2. The use of guidelines is recommended for assessing Good Manu- facturing Practices and the quality of the original fruit. The subcommittee recommends culturing for aciduric microorganisms, or testing for micro- bial metabolic products such as diacetyl in citrus juices and patulin in apple juice, where applicable. 3. Limits for heat-resistant mold spores serve a useful purpose in pur- chase specifications for ingredients that are to be used in pasteurized fruit drinks. Limits for yeasts, molds, and aciduric bacteria are recommended when the ingredients are to be used in products that depend upon preser- vatives for their stability.
36 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA Canned Foods: Low-Acid, Acid, and Water Activity Controlled In the United States, thermally processed foods commercially packaged in hermetically sealed containers have an excellent health record. Control of safety and stability of these foods is best accomplished by monitoring a series of critical control points by physical and chemical control tests. These measures, embodied in federal regulations, should be continued and strengthened when necessary. Cereals and Cereal Products 1. Microbiological standards for cereal grains and most milled products are not recommended because these commodities are not common causes of foodborne illnesses. Cereal products to be used as ingredients in dry- blended or formulated foods that might not receive adequate cooking should be free of infectious pathogens. The current standards for aflatox- ins, on the other hand, are appropriate and it is possible that limits for other mycotoxins may be needed as new problems become apparent. 2. Soy products that do not receive a terminal heat process should be examined for salmonellae since these foods are susceptible to contami- nation by this pathogen. 3. Microbiological guidelines for cereal grains and their milled products generally are not recommended because these foods are raw agricultural products that present little opportunity for microbial growth during their processing. 4. The continued use of specifications that limit the incidence of ther- mophilic spores in cereal products to be used in canning is recommended. 5. Dried pasta products may be contaminated at times with salmonellae and manufacturers should routinely test for this organism. 6. Although cream- and custard-filled pastries have been implicated in numerous disease outbreaks, usually due to staphylococci, standards are not recommended for these foods. Prevention is better achieved by ob- serving Good Manufacturing Practices and proper refrigeration during marketing. Fats and Oils Peanut Butter 1. Peanut butter manufacturers should be encouraged to provide for complete separation between raw peanuts and the peanut butter processing areas.
RECOMMENDATIONS sible. 37 2. Use of water for cleaning and sanitizing should be avoided if pos 3. A microbiological standard for Salmonella in peanut butter is ap- propriate. Salad Dressings and Mayonnaise The microbiological safety of these products relates directly to the pH (4.1 or below) and the acetic acid content of the moisture phase. The federal standards of identity for mayonnaise and for salad dressing do not specify a pH level for either of these products. Also, no specific concen- tration of acetic acid is specified for salad dressing. The FDA should consider amending the standard of identity for may- onnaise to include a specified pH level of 4.1 or below and amending the standard of identity for salad dressings to include both a specified pH level of 4.1 or below and an acidity of not less than 2.5% calculated as acetic acid. Sugar, Cocoa, Chocolate, and Confectioneries 1. Microbiological specifications now applied to sugar used as an in- gredient in low-acid canned foods (thermophilic spores), beverages (me- sophilic bacteria, yeasts, and molds), and confectioneries (osmophilic yeasts) should be continued. 2. Microbiological specifications for thermophilic spores should be ap- plied for cocoa to be used in retorted products. 3. The Salmonella hazard in cocoa and chocolate manufacture should be controlled by testing raw materials, finished products, and environ- mental samples for Salmonella, preferably as part of a HACCP program. 4. In the manufacture of confectionery products, microbiological cri- teria should be applicable to sensitive ingredients. Guidelines and speci- f~cations for osmophilic yeasts should be applicable for sweeteners. Ingredients such as cocoa, coconut, dried milk, and eggs should be ex- amined for Salmonella. Nuts should be tested for aflatoxins. Spices Microbiological criteria for spices should be closely related to their end use. For spices to be used in foods that receive no further heat treatment the criterion should be focused on absence of infectious pathogens such as Salmonella. For spices to be used in low-acid canned food, limits on thermophilic spores should be included. When used as an ingredient in
38 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA cooked cured meats, the emphasis should be on control of aerobic spore- formers. 2. Where appropriate, reduction of the intrinsic microflora of spices by treatment such as approved gaseous "sterilants" and by irradiation is recommended. Yeasts 1. The continued routine testing for salmonellae in yeast products is recommended since they are at times prone to contamination by this pathogen. 2. The establishment of guidelines for nonpathogenic bacteria, wild yeasts, and molds is encouraged to assess Good Manufacturing Practices. Formulated Foods 1. Because of the diversity and different characteristics of the various formulated foods, no single microbiological criterion is appropriate for these foods. 2. Potential hazards of each type of formulated food should be iden- tified. Appropriate programs that embody the HACCP system including microbiological criteria (particularly guidelines as applied at critical con- trol points) should be individually designed for each type of formulated food. ; Nuts Coconut should be tested routinely for salmonellae. 2. Aflatoxin standards should be continued for peanuts and for those tree nuts that are susceptible to contamination by Aspergillus flavus and Aspergillus parasiticus. 3. Purchase specifications that limit molds and other spoilage organisms may be useful when the nuts are to be used as ingredients of foods such as bakery items. Miscellaneous Additives Since little is published about the microbiology of these additives with the exception of carmine color, specific regulatory criteria other than judgments based on the provisions of Section 402(a) 1,3,4,-of the Food,
RECOMMENDATIONS 39 Drug and Cosmetic Act (See Chapter 1) cannot be recommended at this time. Manufacturers should routinely test these products to assure their safety and quality. Bottled Water, Processing Water, and Ice 1. There appears to be little evidence of need at the present time for additions to or modifications of existing criteria in FDA regulations for bottled water; however, in view of recent proliferation of vendors of bottled waters including imports, and the variety of water sources used, FDA should reassess periodically the practices of this industry relative to the microbiological and chemical safety of bottled water offered to the public and the adequacy of the present microbiological standards for this product. 2. Water or ice that comes in contact with or becomes part of a food should be from a potable supply and the microbiological criteria for them should at a minimum meet the U.S. Public Health Service's Drinking Water Standards. 3. Increased research efforts should be made toward development of more effective indicators to assure the microbiological safety of drinking water and to develop more rapid, simple, and less costly methods to detect viruses that cause human illness and are transmitted through drinking water or water and ice used in the food industry. Pet Foods 1. Microbiological criteria should be utilized to assure that pet foods are free of Salmonella. 2. Specifications to limit the level of salmonellae in dry and interme- diate moisture pet food ingredients are recommended as a means of re- ducing opportunities for contamination of the finished product. 3. Processors of dry and intermediate moisture pet foods should use microbiological guidelines to aid in assessing the sanitation of processing lines and the efficacy of the critical control points. IMPLEMENTATION OF THE HACCP SYSTEM IN FOOD PROTECTION SYSTEMS (CHAPTER 10) For HACCP use to be broadly realized, it is likely that the utilization of this system relative to microbiological hazards of foods will have to be required by regulation.
40 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA 1. The regulation should include: a. a statement to identify the basic elements of the HACCP system; b. a provision requiring ready availability of monitoring records relating to critical control points and other appropriate information for review by regulatory inspection personnel. 2. Details of the mechanism of applying the HACCP system should be the prerogative of industry. 3. Regulatory authorities should have the option to assess the appro- priateness of selected critical control points, the adequacy of the moni- toring procedures and the actions taken when monitoring results indicate the need for corrective action. 4. Regulatory inspection personnel should be trained in the elements of the HACCP system so that their activities focus on the review of monitoring records as the primary basis for assessing the adequacy of food processor's control programs. 5. The HACCP system should likewise be applied at points in the food chain other than the processing level, i.e., in production, storage, trans- port, retail sales, and at food service establishments. PLANS OF ACTION FOR IMPLEMENTATION OF THE HACCP SYSTEM AND OF MICROBIOLOGICAL CRITERIA (CHAPTER 11) Implementation of the HACCP system and development and imple- mentation of microbiological criteria for foods and food ingredients should be in accordance with the plans of action proposed in Chapter 11 of this report.
