Proper Food Handling to Avoid Foodborne Illnesses

Posted November 30, 2006 - Author: Yen

The various steps of preparing food - thawing, heating, holding, reheating, and serving are all vulnerable to a loss of control leading to an unacceptable health risk if foods are not prepared properly.

Thawing. The package of meat slowly thawing on the kitchen counter used to be a familiar sight, but now thawing frozen meat at room temperature is considered by many food experts to be an unsafe practice. For safe thawing, one of the following methods should be used -

Refrigerator, on the bottom shelf to avoid contaminating other foods with any dripping.
Microwave oven followed by immediate cooking.
As part of the cooking process.

Running cold water over the meat wrapped in protective plastic or placing it in a bath of ice water and frequently replacing the water, are not as safe as defrosting in a refrigerator.

Cross-Contamination. To prevent cross-contamination, all hands, utensils, and surfaces touching raw food should be thoroughly washed and sanitized before being used again for either raw food or cooked food that will not be further heated. Cross-contamination can occur via tabletops, cutting boards, knives, forks, and slicers, as well as aprons, cleaning cloths, and sponges. Cross-contamination commonly occurs when the uninformed person places raw meat on a plate to be carried out to the barbecue, cooks the meat, and then puts it back on the same plate to take it to the table. Dust and soil should be washed off the tops of cans before they are opened. Raw meats should never be stored in the refrigerator above cooked or ready-to-eat foods where they may drip onto the food below.

Heating. One of the most important factors in controlling bacterial growth is temperature, especially during preparation. In fact, most foodborne outbreaks are a result of improper temperature control. Heating foods to a certain temperature and maintaining that heat for a given time, depending on the food, will destroy most microorganisms. The general rule is to keep cold foods below 40^oF (4^oC) and hot foods above 140^oF (60^oC). Foods such as meat and poultry, however, must reach a minimum temperature during cooking in order to ensure safety.

Temperature guide needed to destroy microorganisms in different foods -

Types of Foods	Temperature
Poultry	180^oF (82^oC)
Reheated foods	165^oF (74^oC)
Ground meats	160^oF (71^oC)
Pork	160^oF (71^oC)
Beef	145^oF (63^oC)
Fish	140^oF (60^oC)

The density of the food plays a key role, because heat must penetrate the entire food mass. Since microwaves only penetrate one-half to 2 inches into food, this limits the size and thickness of meats that can be safely cooked in a microwave oven. It is unsafe to cook turkeys in microwave oven, even if they are unstuffed. The short heating time is another concern about the safety of microwave-processed foods.

Holding. When holding foods for extended periods, they must be kept either above or below the temperature danger zone. Food handlers use thermometers to ensure that the food on the serving table meets these guidelines. To put this in perspective, room temperature is usually around 70^oF (21^oC) and in the kitchen it can increase up to 90^oF (32^oC). Critical to controlling bacterial growth is the fact that temperatures under 40^oF (4^oC) retard but do not kill bacteria, while those above 165^oF (74^oC) destroy most microorganisms.

Serving. Serving is an important step of the food production process and another point of vulnerability to contamination. Good personal hygiene on the part of food service employees is essential to the safety of the foods and beverages being served. Even when serving, the 140^oF (60^oC) and 40^oF (4^oC) boundaries must be observed.

Cooling / Reheating. Inappropriately cooled foods are a major cause of food-borne illnesses. Foods should be cooled to below 40^oF (4^oC) within four hours of removal from cooking or they pose a danger to diners. Liquid foods should be placed in shallow pans less than 3 inches deep to cool, and thicker foods in pans less than 2 inches deep. All hot foods must be reheated to at least 165^oF (74^oC) within two hours before serving. In a food service establishment, untouched leftovers are sometimes discarded, because they are a potential source of microbial contamination.