Although the U.S. food supply is the safest of all nations, consumers have a reason to express concern over foodborne illness. While many consumers, often driven by media sensationalism, believe that pesticide residues are the main concern in foods, scientists agree that most foodborne illnesses are of microbial origin. The majority of outbreaks (79%) have involved food manufactured at commercial or institutional establishments followed by food prepared or consumed at the consumer's home. This observation indicates a need to educate foodservice workers and the general public about safe food handling practices.
Five commonly occurring foodborne illnesses include staphylococcal intoxication, Clostridium perfringens food poisoning, listeriosis campylobacteriosis, and salmonellosis infection. Causes for these illnesses are attributed to Staphylococcus aureus, a bacteria present in nose, throat and skin infections; Clostridium perfringens spore forming bacteria generally found in dust, soil and the intestinal tracts of animals; and Listeria monocytogenes, Campylobacter, and Salmonella bacteria known to live and grow in the intestines of humans and animals.
The most significant factors contributing to outbreaks of foodborne disease are:
1. failure to properly refrigerate foods;
2. failure to thoroughly heat processed foods;
3. infected employees practicing poor personal hygiene;
4. preparing foods a day or more before service;
5. incorporating raw (contaminated) ingredients into foods receiving no further cooking;
6. allowing foods to remain at warm temperatures;
7. failure to reheat cooked foods to temperatures that kill vegetative bacteria;
8. cross contamination; and
9. failure to clean and disinfect kitchen or processing equipment.
Preventive actions for these illnesses include proper handling and holding of foods at safe temperatures (below 40°F or above 140°F), the exclusion of food handlers with respiratory illnesses, infected cuts or burns, the avoidance of hand contact with food, the isolation of raw components that may cross contaminate cooked menu items, and strict personal hygiene. However, the responsibility for a safe food supply should be accepted by everyone.
Pathogens such as Salmonella which cause thousands of foodborne illnesses annually, may be a contaminant of the meat that foodservice institutions and consumers receive in their kitchens. Therefore, it is imperative that livestock producers and meat processing plants adopt procedures and plans to reduce the level of contamination of their outgoing products. This is especially important when the finished product is cooked and ready to be eaten by the consumer.
A summary of foodborne disease outbreaks in the United States reported by the Centers for Disease Control implicates beef, the most commonly consumed muscle food, in 9% of all outbreaks and 10% of all cases. The organisms involved were mainly Campylobacter, Salmonella sp., Clostridium perfringens and Staphylococcus aureus. Additionally, Escherichia coli O157:H7 was the causative agent of outbreaks in 1988 and 1993 in which precooked hamburger patties were implicated.
Although the past 15 years have seen a steady decrease in the proportion of outbreaks and cases associated with beef, it remains a major vehicle for foodborne illnesses, second only to finfish in the number of outbreaks it caused.
While quality assurance plans have been implemented by many processors for several years to address these issues, the industry is now embracing the application of Hazard Analysis and Critical Control Points (HACCP) principles to further minimize the risk of foodborne illnesses. HACCP concepts date back to the 1960s and have their roots in the space program. The concept was later adapted to commercial food processing operations, starting with the Pillsbury company, where it proved its worth in providing safer food.
Briefly stated, the concept calls for identifying those points in an operation which are important in the prevention of significant foodborne hazards and identifying the hazards associated with each such point. Controls are then established at these critical points and systematically monitored to prevention of a hazard. A major advantage of this prevention program is that the responsibility for food safety is placed on the industry. The crux of this program is that the food industry must prevent the occurrence of hazards and maintain records to verify that the subject is safe.
The nutritive value and handling of foods from harvest through consumption contributes to the vulnerability to food spoilage microorganisms and those that cause foodborne illness. The five microorganisms that are most likely to be involved in foodborne illnesses are Staphylococci, Clostridium perfringens, Listeria monocytogenes, Campylobacter, and Salmonella. The best preventive measures are rigid temperature control, sanitary practices, and the application of the HACCP concept.
* Mr. Marriott, Professor of Food Science at Virginia Polytechnic Inst., is the author of two textbooks on food sanitation, and has worked in the food industry in food processing, sanitation, and distribution.
This Article was Provided by the Technical Assistance Bureau.