To establish any national and international standards for microbiological, chemical, or physical hazards in food, it is essential to understand that there will probably always be a risk factor associated with some contamination of food. If food is grown in the ground or is associated with soil, there will always be the likelihood that the food will be contaminated with pathogens such as Bacillus cereus, Clostridium botulinum, and Listeria monocytogenes, as well as molds and parasites. Rodents, insects, and wild birds are known to carry infections to farm animals, poultry, and fish. Meat and poultry products produced in a typical farm environment may be contaminated with Salmonella spp, Campylobacter jejuni, Escherichia coli, and other pathogens. Fish and shellfish are likely to be contaminated with Vibrio spp. Some contamination from the natural environment will always be present.
Development of vaccines to be used for meat animals and poultry so that they are not colonized with pathogens may be one method of control in the future. Another method of control is raising animals and poultry in a pathogen-reduced environment. However, raising animals without some degree of environmental contamination will probably never be possible. This means that pathogenic substances in foods must be reduced to low risk levels by pasteurization, cooking, addition of acid, fermentation etc., or by reduction in population accomplished by washing food items. These controls must be applied so that the risk of making consumers ill depends on the functioning immune system of each individual.
of Pathogens in Food
The following table as compiled by CAST (27) reports the pervasiveness of pathogens in food.
(a) Potentially Hazardous Food means a FOOD that
is natural or synthetic and that requires temperature control because it
is in a form capable of supporting:
(i) The rapid and progressive growth of infectious or toxigenic microorganisms;
(ii) The growth and toxin production of Clostridium botulinum; or
(iii) In raw shell eggs, the growth of Salmonella enteriditis.
(b) Potentially Hazardous Food includes an animal FOOD (a FOOD of animal origin) that is raw or heat-treated; a FOOD of plant origin that is heat-treated or consists of raw seed sprouts; cut melons; and garlic and oil mixtures that are not acidified or otherwise modified at a food processing plant in a way that results in mixtures that do not support growth as specified under subparagraph (a) of this definition.
(c) Potentially Hazardous Food does not include:
(i) An air-cooled hard-boiled egg with shell intact;
(ii) A FOOD with an aw value of 0.85 or less;
(iii) A FOOD with a pH level of 4.6 or below when measured at 24ºC (75ºF)
(iv) A FOOD, in an unopened hermetically seal container, that is commercially processed to achieve and maintain commercial sterility under conditions of nonrefrigerated storage and distribution;
(v) A FOOD for which laboratory evidence demonstrates that the rapid and progressive growth of infectious or toxigenic microorganisms or the growth of S. enteritidis in eggs or Clostridium botulinum can not occur, such as a food that has an aw and pH that are above the levels specified under Subparagraphs (c) (ii) and (iii) of this definition and that may contain a preservative, other barrier to the growth of microorganisms, or a combination of barriers that inhibit the growth of microorganisms; or
(vi) A FOOD that does not support the growth of microorganisms as specified under Subparagraph (a) of this definition even though the food may contain an infectious or toxigenic microorganism or chemical or physical contaminant at a level sufficient to cause illness.
The FDA definition for potentially
hazardous food is limited to the microbiological safety of food.
Also, stating that "potentially hazardous food does not include foods
with a pH of 4.6 or below when measured at 24°C (75°F)" is
a point of concern. A pH of 4.6 or below is necessary to control
the spore outgrowth of C. botulinum in pasteurized food. However,
in food that is not pasteurized, vegetative pathogens must be considered.
The vegetative pathogen of concern is Salmonella spp., which can multiply
down to a pH of 4.1 (94, 165). In order to assure the safety of salad
dressings and mayonnaise, these products are acidified to a pH of 4.1 or
less. For example, the aqueous phase of mayonnaise contains 9.0-11.0%
salt and 7.0 -10.0% sugar. The aqueous phase of salad dressings has
a 3.0-4.0% salt and 20 to 30% sugar. Zhuang et al. (201) showed thatSalmonella
montevideo will multiply in chopped, fully ripe tomatoes with an initial
pH of 4.1 - 4.3 when stored at 20°C (68°F) and 30°C (86°F).
Table 2-2 shows that when the three classes of hazards -- microbiological, chemical, and physical are considered, no food can be excluded from being considered to be potentially hazardous. Each step in the production of food from farm to fork must be examined, and the probability of failure of potential hazard controls and hazard development must be analyzed.
|MEAT: Beef; roasts steaks, stews, pies,
liver, tongue, gravy, processed products.
Pork; ham, bacon, roasts, chops, spareribs, barbecued, and processed pork products
Veal; Lamb; Goat; hamburger and other ground meats; frankfurters and other sausages; luncheon meats; game meats
MARINE FOODS: Fish; salmon (home canned, processed, eggs), tuna, herring, mackerel, sardines, trout, sole, cod.
Shellfish; clams and clam chowder, shrimp, crab, lobster, oysters, scallops, squid, mussels.
POULTRY: Chicken: fried, roasted, barbecued, pies, soup, processed products, gravy, prepared dishes.
Turkey: roast, pie, loaf, dressing, stews, stuffing, soup, gravy. Cornish hen; duck; goose liver pate; roast goose.
DAIRY FOODS: Milk (pasteurized, raw, canned, evaporated), milk shakes, egg nog, cream sauce, artificial cream, mousse, cream, butter, yogurt, cheese, ice cream.
BAKERY FOODS: Pizza, cakes, pastries, pies and tarts, puddings, pasta products, bread and muffins, doughnuts, pancakes and crepes, cereal, tacos, pretzels, cookies, biscuits and crackers.
EGGS: Omelets, scrambled eggs, Hollandaise sauce, deviled eggs, fried eggs, hard-cooked eggs, prepared products with eggs.
INFANT FOODS: Canned formulas, formula (container not specified), cereal products, beef products in jars, fruit, vegetables.
CONFECTIONERY: Chocolate candy, candy bars, licorice, molasses and honey.
VEGETABLES AND FRUITS: Canned and bottled low acid products, canned and bottles acid products, potatoes, mushroom, wild mushrooms, soup, corn and corn products, beans, vegetable oil, greens (lettuce, broccoli, etc.), molasses, maple and corn syrup, canned tomato juice, other canned and bottled fruit juices, other fruit juices, bottled acid fruits, nuts and nut products, jams and marmalades, dried and preserved fruit.
SALAD: Potato, coleslaw, vegetable salads, chicken, seafood, ham, egg, fish, meat, macaroni, multiple ingredients.
SANDWICHES: Beef, ham or ham salad, luncheon meats, turkey or chicken, tuna or tuna salad, other fish or shrimp, cheeseburger, sandwich spreads, egg or egg salad, cream cheese, submarine sandwiches, other multiple ingredient sandwiches.
BEVERAGES: Bottled soft drinks, canned soft drinks, bottled, beer, cider, coffee, tea, spirits, wine, flavoring crystals.
MISCELLANEOUS: Margarine, fats and oils, chili sauce, sloppy joes, gravy, soups, seasoning mix, cider vinegar, fish and ships, macaroni and cheese, custard, other multiple foods, popsicles and slush, spaghetti and meatballs, Mexican food, snails and escargots, tube feeding formulas, dressings and dips, sauces and relishes.
* Adapted from Health Protection Branch Canada. 1996. Food and Waterborne Disease in Canada, Annual Disease Summaries 1988 and 1989. (82)
Are Immune Compromised
Persons who are considered to have reduced resistance to illness include: infants; hospital patients; pregnant women; frail, elderly people; malnourished individuals; people with controlled physical or metabolic disorders (e.g., diabetes or high blood pressure); people with AIDS.
Table 2-3 is a list of factors that increase the risk of foodborne infection or severity of illness. (If Table 2-3 does not print properly, click here for separate image.)
Because of these factors, some individuals are very sensitive to low
levels of microbiological contaminants and are at greater risk of severe
illness and even death from foodborne disease. In hospitals or health
care facilities, it is easy to assure that these people receive more thoroughly
pasteurized food. In the public feeding arena, operators have no
idea of the immune status of their customers. It is very difficult
for an operator to control safety when there is no requirement for the
consumer to declare his or her susceptibility to disease which may, in
fact, vary from day to day. The critical control point in this regard
is a properly educated consumer who knows the risks associated with food
and asks questions of the operator to determine the risk associated with
consuming a food being sold. If the operator cannot provide hazard
information, the consumer must choose another, less risky item.
If people are immune suppressed due to illness or immuno-suppressant drug therapy, they must request food that is well cooked or otherwise made safe for their consumption, because retail food operators have no way of identifying these individuals.
A food can only be considered safe to eat when it has received a process such as canning, which makes the food safe until the container is opened; or when every step from the food source to the point of consumption is analyzed, and it is determined that hazards are controlled to minimize risk to the person consuming the food. Differences in the immunity of consumers must be considered. An increasing number of people are immune suppressed due to chemotherapy, transplant operations, and HIV. These individuals should never engage in high-risk food behavior such as consuming rare beef or raw seafood, or even raw vegetables.
In 1992, the National Advisory Committee on Microbiological Criteria for Foods (NACMCF) (135), using ideas provided by the National Academy of Sciences (134) and principles well established in food process quality control for many years, elaborated the seven principles of HACCP and guidelines for their application. Revision of these guidelines was published in 1998 (135). This is presented in a compact form in Table 2-4. (If Table 2-4 does not print properly, click here for separate image.)
The seven principles of HACCP
program must be included as a part of a total system safety management
program. The EPA and OSHA concept called Process Safety Management
is a more complete management program. The components of Process
Safety Management are contrasted with the seven principles in Table 2-5.
Since Process Safety Management is a complete control and improvement process,
and food operators must also comply with EPA and OSHA regulations, it is
reasonable to incorporate the added features of Process Safety Management
(Adapted from OSHA and EPA Process Safety Management)
| 1. Top-down management commitment to employee empowerment
and then, enforcement of procedures and standards
a. The company's values, vision, focus and goals
b. The process for prevention and improvement:
Check / Measure -> Plan -> Act to change -> Operate -> Check / Measure
2. The HACCP team
3. The operating system
a. The products, distribution, and service
b. The intended product use and consumers
c. The processes (flow chart)
4. The organization chart
a. For each person, describe responsibilities
5. Process change management
6. Current process safety technical information, standards, guidelines, codes, and laws
7. Capital review and facilities and equipment design
8. Process risk assessment and documentation (Principles 1, 2, 3*)
a. Process hazard analysis
b. Consequence analysis
c. Risk analysis
9. Preventive control policies, procedures, and standards for safe, zero-defect work practices
10. Employee empowerment for zero-defect performance
a. Training -- human factors -- for mastery
2) Maintenance and cleaning
b. Behavior assurance (antecedents and consequences)
11. Environment, facilities, and equipment pre-operation performance assurance
12. Formal start-up safety review each morning and during operations for performance assurance
13. Operation; measurement of performance; control within safe limits (Principles 4, 6*)
14. Emergency response plans (Principle 5*)
15. Investigation of incidents; feed forward to the reduction of risk of deviation / defect in the next cycle
16. Periodic evaluations of the (safety) quality assurance process to find opportunities for improvement (Principle 7*) / reduction of risk
17. Revision and improvement of food process safety management program
* Related to NACMCF-HACCP
to Section 1
to Section 2 (part B)
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