Notes - Food Safety

CHAPTER 04 : FOOD SAFETY AND SANITATION

Sanitation refers to the creation and maintenance of conditions that will prevent food contamination or food borne illnesses. Contamination refers to the presence, generally unintended, of harmful organisms or substances. These contaminants can be

1. Biological
2. Chemical
3. Physical.

When consumed in sufficient quantities, food borne contaminants can cause illness or injury, long lasting disease or even death. Contamination occurs in two ways

– direct contamination and

– cross contamination.

Direct contamination is the contamination of raw food or the plant or animals from which they come. Chemical or biological contaminants such as bacteria and fungus are present in the air, soil and water. So foods can be contaminated by their exposure to the environment. Grain can get contaminated by soil fumigants in the field and seafood can be affected by ingesting toxic marine algae.

Chemical and microorganisms cannot move on their own however. They need to be transported, an event known as Cross-contamination. The major cause of cross-contamination is people. Food handlers can transfer biological, chemical or physical contaminants to the food while processing, preparing, cooking and serving the food. It is necessary therefore to view sanitation as the correction of problems caused by direct contamination and the prevention of problems caused by cross-contamination during processing and service.

BIOLOGICAL CONTAMINANTS

Several micro organisms, primarily bacteria, cause biologically based food borne illnesses. By understanding how these organisms live and reproduce you can better understand how to protect food from them.

Bacteria:

Bacteria which are single celled micro organisms are the leading cause of food borne illnesses. Some bacteria are beneficial such as those that aid in digesting food or decomposing garbage. Other bacteria spoil food, without rendering it unfit for human consumption. These bacteria called putrefactive are not a sanitation concern. The bacteria that are dangerous when consumed by humans are called pathogenic. These bacteria must be destroyed or controlled in a food service operation. Most bacteria reproduce by binary fission. Their genetic material is first duplicated and the nucleus then splits, each new nucleus taking some of the cellular material with it. Under favorable conditions, some bacteria can divide every 15-30 minutes. Within 12 hours, one bacterium can become a colony of 72 billion bacteria, more than enough to cause a serious illness. Some rod shaped bacteria are capable of forming spores. Spores are thick wall structures used as a protection against hostile environment. The bacteria essentially hibernates within their spores where they can survive extreme conditions that would otherwise destroy them. When conditions become favorable, the bacteria returns to a viable state. This is important in food sanitation because heating or sanitizing techniques may not destroy bacterial spores.

Intoxications and infections: Depending upon the particular micro organisms, pathogenic bacteria can cause illnesses in humans in one of the three ways:

- Intoxications,

- Infections and

- Toxin medicated infection.

Botulism is a well known example of an intoxication. Certain bacteria produce toxins, byproducts of their life processes. You cannot smell, see or taste toxins. Ingesting these toxin producing bacteria by themselves does not cause illness. But when their toxins are ingested, the toxin can poison the consumer. Proper food handling techniques are critical in preventing an intoxication because even if a food is cooked to a sufficiently high temperature to kill all bacteria present, the toxins they leave behind are usually not destroyed.

The second type of bacterial illness is an infection. Salmonella is an especially well known example. An infection occurs when live pathogenic bacteria (infectants) are ingested. The bacteria then live in the consumers intestinal tract. It is the living bacteria, not their waste products, that cause an illness. Infectants must be alive when eaten for them to do any harm. Fortunately, these bacteria can be destroyed by cooking foods to sufficiently high temperatures of 65°F (74°C) or higher. The third type of bacterial illness has characteristics of both – an intoxication and an infection, and is referred to as a toxin mediated infection. Examples are Clostridium Perfringens and E Coli. When these living organisms are ingested, they establish colonies in human or animal intestinal tracts, where they then produce toxins. These bacteria are particularly dangerous for young children, the elderly and the infirm.

PREVENTING BACTERIAL INFECTIONS AND INTOXICATIONS.

All bacteria, like other living things need certain conditions to complete their life cycles. Like humans, they need food, a comfortable temperature, moisture, the proper PH, the proper atmosphere and time. The best way to prevent bacterial intoxications and infections is to attack the factors that bacteria need to survive and multiply.

FOOD: Bacteria need food and energy for growth. The foods on which bacteria thrive are referred to as potentially hazardous foods (PHF).They are generally high in protein and include animal based products, cooked grains and some cooked vegetables. These foods and items containing these foods must be handled with great care.

TEMPERATURE: Is the most important factor in the pathogenic bacterial environment, because it is the factor most easily controlled by Food Service workers. Most micro organisms are destroyed at high temperatures. Freezing slows but does not stop growth, nor does it destroy the bacteria. Most bacteria that cause food borne illnesses multiply rapidly at temperatures between 60°F and 120°F(16°C and 49°C). Therefore, the broad range of temperatures between 40°F and 140°F (6°C and 60°C) is referred to the food danger zone. By keeping foods out of the temperature danger zone, you decrease the bacteria’s ability to thrive and reproduce. To control the growth of any bacteria that may be present, it is important to maintain the internal temperature of food at 140°F (60°C) or above OR 48°F (6°C) or below. Simply stated, keep hot foods hot and cold foods cold. Potentially hazardous foods should be heated or cooled rapidly so that they are within the temperature zone as briefly as possibly. This is known as the Time and Temperature Principle.

Keep hot foods hot. The high internal temperatures reached during proper cooking kill most of the bacteria that can cause food borne illnesses. When foods are reheated, the internal temperature should quickly reach or exceed 165°F (74°C) in order to kill any bacteria that may have grown during storage. Once properly heated, hot foods should be held at temperatures of 140°F (60°C) or above. Foods that are displayed or served hot must be heated rapidly when heating or reheating foods to reduce the time in the danger zone. When heating or reheating foods

- heat small quantities at a time

- stir frequently

- heat food as close to service time as possible

- use pre heated ingredients wherever possible to prepare hot foods

- never use a steam table for heating or reheating foods

- bring reheated food to an appropriate temperature (165F or 74°C)

Keep cold foods cold : Foods that are to be displayed, stored or served cold must be cooled rapidly.

- Refrigerate semi solid foods preferably at 40°F (4°C) or below in containers that are less that 2” deep. Increased surface area decreases cooling time.

- Avoid crowding the refrigerator. Allow air to circulate around the foods.

- Vent hot foods in an ice water bath.

- Pre chill ingredients such as mayonnaise before preparing cold foods.

- Store cooked foods above raw foods to prevent cross contamination.

Keep frozen foods frozen : Freezing at 0°F (-18°C) or below essentially stops bacterial growth but will not kill the bacteria. Do not place hot foods in a regular freezer. This will not cool the food any faster and the release of heat can raise the temperature of the other foods in the refrigerator. Only a special blast freezer can be used for chilling hot items. If one is not available, cool hot foods as mentioned earlier before freezing them. When frozen foods are thawed, bacteria that are present will begin to grow.

Therefore:

- never thaw foods at room temperature.

- Thaw foods gradually under refrigeration to maintain the foods temperature at 40°F or less. Place thawing foods in a container to prevent cross-contamination, from leaking or dripping liquids.

- In an emergency, thaw foods under running water at a temperature of 70°F or 21°C or cooler.

- Thaw foods in a microwave only if the food is prepared and served immediately.

CHEMICAL CONTAMINANTS

Contamination of foods by a wide variety of chemicals is a very real and serious danger. Chemical contamination is usually inadvertent and invisible, making it very difficult to detect. The only way to avoid such hazards is for everyone working in the food service operation to follow proper procedures when handling food or chemicals. Chemical contamination could be caused by

- residual chemicals

- food service chemicals

- toxic metals

Residual chemicals such as antibiotics, fertilizers, insecticides and herbicides have brought about great progress is controlling plant animal and human disease. Thereby permitting greater crop yield and stimulating animal growth. The benefits derived from these chemicals however must be contrasted with the adverse effect on humans when they are used indiscriminately or improperly. The danger of these chemicals lies in the possible contamination of human food , which occurs when the chemical residues remain after the intended goal is achieved. Fruits and vegetables must be washed and peeled properly, lentils and dals should be washed and then soaked and this water discarded to make sure the risk of chemical contamination is reduced and if possible removed altogether to ensure chemical residues are not consumed.

Food service chemicals such as cleaners, polishes and, abrasives pesticides which contain common chemicals are found in every food service operation. Serious illness and even death can be caused if these chemicals contaminate the food. Common products like bug spray, drain cleaner and oven cleaner can pose a hazard if stored near food. Even cleaning soap used on plates and dishes can cause contamination if not properly rinsed off. To avoid such contamination, ensure that all food service cleaning material is properly labeled and stored away from any food related items or near cooking areas. Nerve reuse empty containers again for food service even if properly washed.

Toxic metals are another type of chemical contamination and occurs when metals such as lead, mercury, zinc, antimony or copper are dispersed in food or water.

- Metals can accumulate in fish and shell fish living in polluted waters or also in plants grown in soil contaminated by these metals.

- Using an acidic food such as tomatoes or wine in a zinc lined(galvanized) or unlined copper vessel can cause metal ins to be released in the food.

- Antimony is used in the bonding of enamelware and it can be released into food when the enamel is chipped.

- Lead enters the water from lead pipes and solder and is found in the glaze on some ceramic tiles.

Consuming any of these metals can be poisonous. Be cautious in using service ware or cookware that might be susceptible to poisoning.

PHYSICAL CONTAMINANTS

Physical contamination san be caused by foreign objects finding their way into the food. These might be inadvertent and could be pieces of string or rope in a gunny bag of flour, metal shavings caused by an old can opener, pieces of glass from a broken container or even hair and dirt in some prepared food. However, physical contamination can be caused intentionally and purposely as incases of Food Adulteration. This can be harmful and lead to serious and sometimes fatal consequences and will be dealt with in a later chapter.

CROSS-CONTAMINATION

Generally, microorganisms and other contaminants cannot move by themselves. Rather, they are carried to food and food contact surfaces by humans, rodents such as rats and mice or insects. This transfer is referred to as cross-contamination.

For example, one item such as your finger or the cutting board becomes contaminated and then contaminates some other food or tool such as your knife. Using a knife to cut raw chicken and then using the same cutting board or knife (without washing/disinfecting it first) to cut salad ingredients to be eaten raw; will cause cross contamination to occur.

Cross-contamination can occur with bacteria or other microorganisms, chemicals, dirt and debris. Kitchen towels, dusters and other such cleaning material are a common source of cross-contamination. If a cook uses such a duster to wipe of some spill from the floor and then uses the same to wipe his hands after visiting the rest room, he has re contaminated his hands with whatever dirt or bacteria was on the floor. Cross=contamination also occurs when raw food comes into contact with cooked foods. Never store cooked food below raw /defrosting food in the refrigerator unless covered. Never use a container that had raw food to store cooked food unless properly sanitized. Cross-contamination can easily occur from smoking in the kitchen and therefore this useless activity is totally banned in all kitchens and food service operations. Personal hygiene and cleanliness, equipment and dish sanitizing and pest management can reduce cross-contamination.

HACCP SYSTEMS

Hazard Analysis and Critical Control Points (HACCP) is proving to be an efficient and effective system for managing and maintaining sanitary conditions in all types Food Service operations. Developed in 1971 by NASA to ensure food safety for astronauts, HACCP is a stringent and rigorous system of self inspection. It focuses on flow of food through the food service facility from the time the decision is made to put an item on the menu to ordering and receipt of ingredients from the supplier, to receiving the raw material, inspection, storage, issuing, pre preparation , cooking, portioning and presentation and finally the service. These activities that pose the maximum risk (critical points) should be closely monitored to prevent the growth of dangerous pathogenic bacteria.

Note that standards/boundaries applied in a formal HACCP system are no different from those that should be followed in any food service operation. HACCP does not impose new or different food safety standards. It is merely a system for assuring that those standards are actually followed. One way of to assure compliance is to frequently check and record the temperature of Potentially Hazardous Foods (PHF) during cooking, cooling and holding. Whatever system is followed, all personnel must be constantly aware of and responsive to risks and problems associated with the safety of the food they serve.

THE SAFE WORKER

The kitchens are filled with objects that can cut, burn, break, crush or sprain the human body. The best way to prevent work-related injuries is proper training, good work habits and careful supervision.

Safe behavior on the job reflects pride, professionalism and consideration for fellow workers. The following should alert you to conditions and activities aimed at preventing accidents and injuries.

- clean up spills as soon as they occur.

- Learn to operate equipment carefully and correctly.

- Wear clothes that fit properly

- Avoid jewelry that may get caught in the equipment.

- Use knives and such equipment for their intended use only.

- Walk, do not run.

- Keep exits, aisles and staircases free from obstruction.

- Always assume pots and pans are hot and use dry towels to handle them.

- Position handles of pots and pans away from the aisle.

- Get help when moving heavy containers. Get help if necessary.

- Be careful when lifting heavy objects. Squat and then lift, do not bend.

- Use appropriate ladder when climbing, not a chair which was intended to sit on, not stand.

- Warn people when you must walk behind them especially when carrying a hot pan.

- Use disposable gloves when handling cooked food and foods that are to be served raw. Change gloves when handling different foods.

Yet, inevitably, some accidents will occur. In an emergency, it is important to act appropriately. This could mean calling for help or to provide First Aid. Every Food Service facility must carry a complete First Aid kit which is easily accessible. All employees must be trained in basic First Aid procedures and a list of emergency telephone numbers readily available.

VERNON COELHO

IHM MUMBAI

2009-10