By Marilyn Collins
Environmental Health Specialist Report (EHS 2015) detailed a study in which 448 food managers in a focal group admitted that inadequate chicken preparation and improper cooking practices were common occurrences. Forty percent 40% of them stated that they frequently failed to assign dedicated colour- coded cutting boards for raw meat (including chicken); 29% said that they did not wash and rinse surfaces prior to sanitizing them, and over 50% said that thermometers were not used to determine the final cook temperature of chicken. Only 43% of managers knew the recommended temperature (165oF) for the cooking of raw chicken. This is not particularly encouraging news for consumers.
Were a similar survey to be conducted among the food service managers in Guyana—restaurants, fast food and street food vendors etc—the survey results would probably yield an even greater deficiency in terms of knowledge of the basic tenets of food hygiene.
When food hygiene principles are vitiated it could result in food poisoning outbreaks with devastating economic effects to the entity and the country as a whole and with debilitating morbidity and mortality consequences to consumers.
As Guyana continues to seek to build a tourism industry food managers must begin to transform theoretical food safety training into food safety practice. Behavioral change is critical to the protection of visitors and to consumers at large,
This discussion will examine three broad areas that regulators and the food service establishment should focus on in the quest for enhanced food safety. These are:
(1) The identification and elimination of all areas of cross contamination,
(2) Conditions that allow for the growth and multiplication of microorganisms, and
(3) Conditions that will facilitate the survival and regrowth of spoilage and pathogenic (disease causing) microorganisms.
Contamination
Bacteria (pathogens) can be transferred to food from utensils, food contact surfaces such as, cutting boards, food workers’ hands, raw meats, poultry, fish and seafood. This transference of harmful substances or the presence of disease-causing microorganisms to foods is referred to as contamination.
Food can become contaminated at any time and by other foods. To help prevent cross-contamination, raw meats, fish, and poultry must be kept away from cooked and ready-to-eat foods. There should be separate cutting boards, separation of duties in the preparation of fresh produce and ready to eat foods and the evidence of hygienic design and layout of the preparation area.
Uncontrolled thawing of meat could result in cross contamination, since the drip from meat is a rich medium for the growth of microorganisms. Thawing must be done so that the risk of cross-contamination is reduced, and the time that potentially hazardous food is in the temperature danger zone (41°F to 140°F) is kept to a minimum. Thawing foods may take several hours or days depending on the size of the food item being thawed. The following procedures should be taken to thaw food safely:
- Thaw under refrigeration (41°F and below)
- Under cold running potable water (safe to drink) of 70ºF or less as part of the cooking process.
- In a microwave then transferred to conventional cooking equipment with no interruption in the process.
Growth and multiplication of organisms
Cooking is not a sterilization process and its requirements are based on the biology of pathogens. To kill all pathogens in foods cooking must bring all parts of the food to required temperature for a correct length of time. Temperature is one of the prime factors that control the growth of bacteria in food. Many types of pathogens and spoilage bacteria are prevented from multiplying to significant levels that cause food-borne illness with proper holding practices. All foods need to be stored at 41°F and below or hot 140°F or above.
The amount of heat required to destroy the organisms will vary. Different species of microorganisms are susceptible to varied levels of heat. Food characteristics also contribute to the lethality of cooking temperatures; cooking protocols are established for different types of meats and varied types of food. Heat penetrates different foods at different rates. High fat content reduces the lethality of heat. High humidity in the cooking container or the moisture content of the food supports the lethality of heat.
To effectively eliminate pathogens, there are a number of factors to consider including the level of pathogens in the raw product, the initial temperature of the food and the bulk of the food. Preparation procedures should have built in barriers to limit the time potentially hazardous foods are in the temperature danger zone of 41°F to 140°F—optimum temperature for the growth of microorganism. Control measures to ensure foods are out of temperature for limited times include:
- Refrigerate foods before preparation.
- Prepare foods not long in advance of serving or consumption.
- Prepare small batches of food and return them to the refrigerator before cooking and serving.
Employee contamination
Proper personal hygiene for food handlers is important for best practices in food handling. Hand washing is one such practice that is critical to break the chain of contamination. Improper hand-washing is known to be the number one cause of food-borne illness.
Employees need to minimize bare hand contact with cooked foods and no bare hand contact of ready-to-eat foods should be permitted. Tools such as spoons, forks, spatulas, tissue, foil and gloves should be used. Equipment, utensils and food contact surfaces must be washed, rinsed and sanitized.
Food service workers should follow written hand-washing protocols. Occasions for hand washing are as prescribed below:
- before starting to work
- during work as necessary to prevent contamination of foods
- after handling unclean items
- after handling raw meat, poultry, or aquatic foods
- after using the restroom (must wash twice, once in restroom and again in kitchen)
- after eating or smoking
Food service workers must maintain a high degree of personal cleanliness, be properly attired with protective attire including hair restraint attire as necessary.
Survival and regrowth
Reheating is the thermal process of heating foods that have been previously cooked and cooled in a food service establishment. Proper reheating to 165°F within two hours, can eliminate a major portion of pathogens.
The more a food is processed, the greater the risk. When food is held, cooled and reheated, there is an increased risk from contamination caused by personnel, equipment, procedures and other factors. When food is cooked and cooled the product goes through the danger zone (optimal temperature range for microorganisms to grow) several times which also increases the risk.
Once food is heated or cooked the food must be maintained at a temperature to limit the growth of bacteria. The correct hot holding temperature is 140°F.
The potential for growth of pathogenic bacteria increases once food is reheated, compared to the potential in raw foods. The spoilage organisms that may be present in raw foods inhibit the growth of pathogenic organisms by competition. Once a food is cooked, these spoilage organisms are reduced.
Cooling is a process of removing heat from food relatively quickly to prevent microbial growth. One method is done by placing foods in shallow containers no deeper than 2 to 3 inches until cool, 41°F or below.
When potentially hazardous food is cooled for an extended period, the food is subject to the growth of a variety of pathogenic micro-organisms. Bacteria grow ideally between 70 – 120°F. (The human body temperature falls in this range). The longer the time the food is allowed to be held in this range, the greater the risk of microbial growth. Excessive time for cooling potentially hazardous food has consistently been identified as one of the leading contributing factors to foodborne illness. Cold holding is storing food under refrigeration at 41°F or below. Refrigeration prevents food from becoming a hazard by decreasing the growth of most microbes. Some organisms like Listeria monocytogenes is significantly slowed but not stopped by refrigeration temperature.
Food service managers who understand the risk of food pathogens and are committed to the food safety will be forward thinking in ensuring that food safety practices are firmly entrenched in its operation. The result will be enhanced competitiveness as consumers develop confidence in the safety and wholesomeness of the food offered for sale. The resolve of the food service sector could be buttressed and encouraged through the use of audits by regulators with conformance used in advertisement and other promotional tools.
