Protecting food during preparation

Serving safe food requires constant attention to the factors that can cause foodborne illness. Even food is safe when delivered and properly stored can quickly become unsafe if handled improperly during preparation and cooking.

Safe foodhandling

The key to serving safe food is to handle it safely. Teach employees how important it is to control time and temperature and to prevent cross-contamination. Then put commonsense guidelines in place for safe foodhandling.

Time and temperature control

Probably the biggest factor in foodborne-illness outbreaks is time-temperature abuse. Disease-causing microorganisms grow and multiply at temperatures between 41F and 140F (5C and 60C), which is why this range is known as the temperature danger zone. Microorganisms grow much faster in the middle of the zone, at temperatures between 70F and 125F (21C and 52C). Whenever food is held in the temperature danger zone, it is being abused.

As you have already learned, time also plays a critical role in food safety. Microorganisms need both time and temperature to grow. The longer food stays in the temperature danger zone, the more time microorganisms have to multiply and make food unsafe. When heating or cooling food, it is important to pass it through the danger zone, as quickly and as infrequently as possible.

To keep food safe during preparation and cooking, you must follow the four-hour rule. Never let food remain in the temperature danger zone for more than four hours.

Exposure time adds up during each stage of handling, from the time food arrives at the receiving dock to the time it is cooked. Once food is properly cooked to the required minimum internal temperature, the number of microorganisms in it will have been reduced to a safe level. However, you must continue to handle the food safely. There are further opportunities for time-temperature abuse, including:

Not cooling food properly

Failing to reheat food to 165F (74C) for fifteen seconds within two hours

Failing to hold food at a minimum internal temperature of 140F (60C) or higher

You can see how four hours in the danger zone easily add up if you don’t handle food carefully. The best way to avoid the problem is to establish procedures employees must follow and then monitor them. Build time and temperature controls into your establishment’s HACCP plan and standard employee’s job. Some suggestions include:

Decide the best way to monitor time and temperature in your establishment. Determine which foods should be monitored, how often, and who should check them. Then assign responsibilities to employees in each area. Make sure employees understand exactly what you want them to do, how to do it, and why it is important.

Make sure the establishment has the right kind of thermometers available in the right places. Give employees their own calibrated thermometers. Have them use timers in prep areas to monitor how long food is being kept in the temperature danger zone.

Regularly record temperatures and the times they are taken. Print simple forms employees can use to record temperatures and times throughout the shift. Post these forms on clipboards outside of refrigerators and freezers, near prep tables, and next to cooking and holding equipment.

Incorporate time and temperature controls into standard operating procedures for employees. These must include:

Not removing from the refrigerator more food than can be prepared in a short period of time

Refrigerating ingredients and utensils before preparing certain recipes, such as tuna or chicken salad

Cooking potentially hazardous food to minimum internal cooking temperatures

Develop a set of corrective actions. Decide what action should be taken if time and temperature standards are not met. For example, an establishment that holds egg rolls on a steam table might throw them out if their internal temperature falls below 140F (60C) for more than four hours, or they might reheat the egg rolls to 165F (74C) for at least fifteen seconds within two hours.

Preventing cross-contamination

The other major hazard for food in your operation is cross-contamination, which is transfer of microorganisms from one food or surface to another. Microorganisms move around easily in a kitchen. They can be transferred from food or unwashed hands to prep tables, equipment, utensils, cutting boards, dish towels, sponges, or other food.

Cross-contamination can occur at almost any point in an operation. When you know where and how microorganisms can be transferred, cross-contamination is fairly simple to prevent. Prevention starts with the creation of barriers between food products. Barriers can be physical or procedural. For example, in Unit 6 you learned to store food in covered containers to make sure that raw meat or poultry is not stored above cooked and ready-to-eat food in a refrigerator.

Prevention is a matter of common sense. Here are some simple barriers you should consider using in your establishment.

Prepare raw meat, fish, and poultry in separate areas from produce or cooked and ready-to-eat food. This can be as easy as using separate prep tables in the same area. If you don’t have sufficient space for separate tables, prepare these items at different times so they don’t cross paths.

Assign specific equipment to each to each type of food product. For example, use one set of cutting boards, utensils, and containers just for poultry, another set for meat, and a third set for produce. Some manufacturers make colored cutting boards and utensils with colored handles. Color-coding can tell employees which equipment to use with what products, such as green for produce, yellow for chicken, and red for meat.

Use specific containers for each type of food product. Clearly label containers with their contents – such as “Raw Chicken” or “Tuna Salad” – so the containers are less likely to be used for something else. Make sure you have an adequate supply of containers on hand and keep them clean and sanitized between uses.

Clean and sanitized all work surfaces, equipment, and utensils after each task. After cutting up raw chicken, for example, it is not enough to simply rinse the cutting board. Wash, rinse, and sanitize cutting boards and utensils in a three-compartment sink, or run them through a ware washing machine. Make sure employees know which cleaners and sanitizers to use for each job. Sanitizers used on food-contact surfaces must meet local or state conforming to the Code of Federal Regulations.

Clothes or towels used for wiping food spills must not be used for any other purpose. There are a few ways to prevent the spread of microorganisms from cleaning cloths to equipment and utensils. One way is to use disposable towels. Another is to use color-coded cleaning cloths that match a specific food-preparation area or task. After each use, cloths or towels must be rinsed and stored in a clean sanitized solution.

Consider requiring employees to wear single-use gloves while preparing or serving ready-to-eat food in your establishment. If you adopt this policy, teach employees to use gloves properly. Employees must wash their hands before putting on gloves. Gloves should be used only for the job at hand and changed each time a new task is started. Hands must be washed before putting on a new pair of gloves. If punctured or ripped, gloves must be changed.

Employees should watch what they touch after handling raw food and should practice good personal hygiene. Hands are the most common cause of cross-contamination in the kitchen. Employees should be trained to wash their hands properly and at the appropriate times.

PREPARING FOOD

Controlling time and temperature and preventing cross-contamination will help keep food from becoming unsafe during preparation. However, some food items and methods of preparing require a bit more care.

Thawing food properly

Often, the first step in food preparation is thawing what you intend to cook. If frozen food is thawed improperly, foodborne microorganisms can rapidly grow to unsafe levels.

Suppose a cook wants to prepare twenty-pound frozen turkey. The cook is in a hurry, so instead of putting the turkey in the refrigerator he puts it in a pan on a worktable to thaw overnight. The air temperature in the kitchen is about 72F (22C).

There are two problems with this method of thawing. First, when the bird begins to thaw, the skin and outer layers are exposed to the temperature danger zone even though the bird’s core is still frozen. Microorganisms may multiply to a point where cooking the turkey may not be sufficient to kill them. The cook may end up serving a potentially dangerous dish to customers.

Second, microorganisms on the turkey may contaminate everything in the area: the cook’s hands, the worktable, the pan, the cutting board, knives, and other utensils. If the area and equipment aren’t completely cleaned and sanitized before the cook starts another task, microorganisms could spread throughout the entire kitchen.

There are only four acceptable ways to thaw frozen food safely.

Thaw food in the refrigerator at 41F (5C) or lower. This method requires advance planning. A twenty-pound turkey can take from two or four days to thaw completely in the refrigerator. Employees need to take food out of frozen storage far enough in advance to make sure there is adequate thawed product on hand when it’s needed.

Submerge the frozen product under running potable water at a temperature of 70F (21C) or lower. The water has to flow fast enough to wash loose food particles into the overflow drain. Make sure the thawed product does not drip water onto other products or food-contact surfaces. Clean and sanitized the sink and work area before and after thawing food this way. Remember, the product cannot remain in the temperature danger zone for more than four hours, which includes both the time the food is thawed under running water and the time needed for preparation prior to cooking.

Food may be thawed in a microwave oven only if it will be cooked immediately afterward. Microwave thawing can actually start cooking the product, so don’t use this method unless you intend to continue cooking the food immediately. Large items such as roasts or turkeys don’t thaw well in the microwave.

Food may be thawed as part of the cooking process as long as the product reaches the required minimum internal cooking temperature. Frozen hamburger patties, for example, can go straight from the freezer onto a grill without being thawed first. Frozen chicken can go straight into a deep fryer. These products cook quickly enough from the frozen state to pass through the temperature danger zone without harm. However, always make sure you verify the final internal cooking temperature with a calibrated thermometer.

Some frozen food may be slacked before cooking. Slacking is the process of gradually thawing frozen food in preparation for deep frying, allowing even heating during cooking. For example, you might allow a large block of frozen spinach to warm from -10F (-23C) to 25F (-4C). Since food should never be refrozen once it begins to thaw, slack food just before you cook it. Don’t let food get any warmer than 41F (5C). if slacking at room temperature is permitted in your jurisdiction, a system must be in place to ensure the product does not exceed 41F (5C).

PREPARING SPECIFIC FOOD

Meat, Fish, and Poultry

The sources of most cross-contamination in an operation are raw meat, poultry, and seafood. Your staff should follow safe procedures when handling these products.

Use clean and sanitized work areas, cutting boards, knives, and utensils. Prepare raw meat, poultry and seafood separately or at a different time from fresh produce.

Be sure hands are washed properly. If gloves are used, change them before starting each new task. Wash hands again before putting on a pair of new gloves.

Remove from the refrigerator only as much product as can be prepared at one time. When cubing beef for stew, for example, take out and cube one roast and refrigerate it before taking out another roast.

Put raw, prepared meat away or cook it as quickly as possible. If put back into storage, wrap raw, prepared meat first or put it in covered containers that are clearly labeled. Store it on bottom shelves in the refrigerator. Never store it above cooked or ready-to-eat food, such as fresh produce, because raw meat juices may drip and cross-contaminate other food.

Salads Containing Potentially Hazardous Food

Chicken, tuna, egg, pasta, and potato salads all have been known to cause foodborne-illness outbreaks. These salads are typically made from food that can easily support the rapid growth of microorganisms. Since they usually will not be cooked after preparation, there is no chance to kill microorganisms that could be introduced during preparation. Therefore, care must be taken to both control time and temperature and prevent cross-contamination when preparing these salads. Handle all ingredients with care and follow these precautions:

Make sure leftover meat and poultry have been properly cooked, held, cooled, and stored. Leftover meat and poultry should be discarded after seven days if stored at the refrigerator at 41F (5C) or lower. (Four days if stores at 45F [7C].) Salads made with these items should be discarded when this storage period expires.

Make sure foodhandlers wash their hands before preparing food and, if required by local health codes, have them wear clean, single-use gloves. Tongs, deli tissue, or other barriers can also be used to protect food.

Prepare other ingredients away from raw meat, seafood, and poultry. Always prepare raw vegetables using clean, sanitary equipment and utensils.

Leave food in the refrigerator until all ingredients are ready to be mixed. For example, don’t take out chicken and leave it on the prep table while you chop the vegetables.

Consider chilling all ingredients before making salads. Refrigerate unopened cans of tuna and jars of mayonnaise the day before you make tuna salad, for example. Consider chilling mixing bowls and utensils, too. Taking these steps will provide additional barriers that might prevent the growth of harmful microorganisms that could be present.

Prepare food in small batches. This will prevent large amounts of food from sitting out at room temperature for long periods of time, set a working time limit of twenty minutes and make sure you take out only enough ingredients to use within that time period. When time is up, refrigerate what you’ve made, then get ingredients to make more.

Eggs and Egg Mixtures

Historically, the contents of whole, clean, uncracked shell eggs were considered free of bacteria. Now it is known that, in rare cases, a certain bacteria, Salmonella enteritidis, can be found inside eggs. Salmonella enteritidis can live inside a laying hen and can be deposited in the white of the egg before the shell is formed. Although only a small number of eggs produced in the United States are likely to carry this bacteria, all untreated shell eggs are considered to be a potentially hazardous food because they are able to support the rapid growth of microorganisms. As a consequence, eggs should be purchased fresh and should be stored and handled properly. Eggs should be kept at an ambient (air) temperature of 45F (7C) or lower until immediately before use. Special handling precautions for eggs are described below.

Use clean bowls, whisks, blenders, and other equipment when working with eggs and other potentially hazardous food items. To prevent cross-contamination, promptly clean and sanitize all equipment and utensils used with eggs. Place freshly made batters or sauces in clean containers. Never reuse containers that held raw eggs, even to replenish the same recipe.

Food containing eggs that receive little or no cooking – such as Caesar salad dressing meringue, mayonnaise, hollandaise sauce, and eggnog – should be prepared with great care. Follow the directions precisely and monitor temperatures using a thermometer. Many jurisdictions now require operators to post a notice to consumers when raw eggs are used as an ingredient in these types of food. The use of pasteurized shell eggs or pasteurized egg products may be a safer alternative when preparing these types of dishes.

Eggs that are cracked open and combined in a container (pooled eggs) must be handled with special care because bacteria present in one egg can be spread to the rest. Cross-contamination from one pooled egg mixture to another may also be a hazard if the food is not prepared or handled properly. Shell eggs must be kept at an ambient (air) temperature of 45F (7C) or lower until immediately before use. Pooled eggs, if used, must be cooked promptly after mixing or stored at 41F (5C) or lower. Containers that held pooled eggs must be washed and sanitized before being used again. There should be no carryover of egg residue from one food batch to another, even if it is the same recipe.

Federal public health officials require that operations serving highly susceptible populations – such as those in nursing homes and hospitals – use only pasteurized shell eggs or pasteurized egg products. This is recommended for all types of eggs and egg dishes served to these people and is required when liquid egg mixtures are prepared, when eggs are cooked and held for service, and when egg-containing food will receive little or no cooking.

Batters and breading

If prepared with eggs or milk, batters and breading are at risk from time-temperature abuse and cross-contamination, so they should be handled with care. In some cases, it may be better to buy frozen breaded items that can be taken directly from the freezer and then cooked thoroughly in the oven or fryer. If you prefer to make breaded or battered food from scratch, follow some simple rules:

Consider making batters with pasteurized egg products instead of raw shell eggs whenever possible.

Prepare batters in small batches and keep what you don’t need in a covered container in refrigerator. Using small amounts prevents time-temperature abuse of both the batter and the food being coated.

When making a batch of batter or breading for later use, store it in the refrigerator at 41F (5C) or lower. Don’t combine it with other batches already stored in the refrigerator.

If you are breading food to cook later, put the breaded food in the refrigerator as quickly as possible.

Cook battered and breaded food thoroughly. The coating acts as an insulator, which can prevent food from being thoroughly cooked. When deep-frying food, make sure the temperature of the oil recovers before loading each batch. Overloading the basket also slows cooking time, which means product could be removed from the fryer before it is thoroughly cooked. Be sure to monitor oil and food temperatures using calibrated thermometers, and watch cooking time.

Throw out any used batter or breading left over after each shift. Whenever a potentially hazardous food is dipped in batter or dredged in breading, consider the batter or breading contaminated. Never use batter or breading for more than one product. For example, dipping raw chicken into batter then using the same batter for onion rings may contaminate the onion rings and possibly make someone sick.

Fruit and vegetables

For the most part, fresh fruit and vegetables are not as likely to carry pathogens as are some other food. But viruses such as hepatitus A, bacteria such as Listeria spp., and parasites such as Cryptosporidium parvum can survive on produce, especially cut produce. The risk of such microorganisms can be minimized or eliminated by simple preparation safeguards.

Start with a clean, sanitized work space. Prepare vegetables away from raw meat, vegetables, and eggs, as well as from cooked and ready-to-eat food, to prevent cross-contamination.

Surfaces that come in contact with raw meat – such as hands, gloves, knives,prep tables, or cutting boards – should never make contact with food that will be eaten raw, such as salad or fruit, unless they have been clean and sanitized.

Wash fruit and vegetables under running water to remove dirt or other contaminants just before cutting, combining with other ingredients, or cooking. Failure to wash fruit before cutting it may result in contamination of the fruit’s interior.

Pay particular attention to leafy items such as lettuce and spinach, because dirt and microorganisms can get into inner leaves. Remove the outer leaves, pull lettuce and spinach completely apart, and rinse thoroughly.

Cut away bruised or damaged areas when preparing fruit and vegetables.

Hold cut melons at 41F (5C) or lower. Discard after four hours if not held at this temperature.

Do not add sulfites to food products.

Juice prepared on-site for service or sale to high-risk populations must be prepared following a HACCP plan.

Ice

People often forget that ice is a food, too. It is used to chill beverages and to chill or dilute food. In Unit 6, you learned how to store products on ice, such as poultry, fish, fruit, and vegetables. Many establishments also use ice to chill food on display, such as canned beverages or fruit. Any time ice has been used to cool food in this way, you may not reuse it as a food.

Ice used as a food, or used to chill other food, must always be made with potable water (water that is safe for drink). Remember, ice can become contaminated just as easily as other food. When transferring ice from an ice machine to an ice bin or to a display, use a clean, sanitized scoop and container. Store ice scoops outside of the ice-machine in a sanitary, protected location. Never hold ice in containers that have been used to store raw meat, poultry, fish, or chemicals.

COOKING FOOD

Whatever cooking method you choose, temperature is key to killing microorganisms that can cause foodborne illness. The food’s internal temperature must reach a certain level for a specific amount of time before you can be sure all foodborne microorganisms have been sufficiently reduced in number. The only way to be certain a food has reached the required minimum internal cooking temperature is to check it using a calibrated thermometer.

The minimum internal temperature at which foodborne microorganisms are destroyed varies from product to product. Minimum standards have been developed for most cooked food and are included in local and state health codes.

Minimum internal cooking temperatures
Product	Temperature
Poultry Stuffing, stuffed meat, and dishes combining raw and cooked food (including soups and casseroles)	165F (74C) for 15 seconds
Ground meats (beef, pork, or other meat or fish)	155F (68C) for 15 seconds
Injected meats (including brined ham and flavor-injected roasts)	155F (68C) for 15 seconds
Pork, beef, veal, lamb	Steaks/chops 145F (63C) for 15 seconds Roasts 145F (63C) for 4 seconds
Fish	145F (63C) for 15 seconds
Fresh shell eggs for immediate service	145F (63C) for 15 seconds
Any potentially hazardous food cooked in a microwave oven	165F (74C) let food stand for 2 minutes after cooking

It is important to remember that potentially hazardous food – such as meat, eggs, seafood, and poultry – should be cooked to the minimum internal temperatures specified in this unit unless otherwise ordered by the customer. Potentially hazardous food not cooked to these temperatures – including over-easy eggs, raw oysters, sashimi, or rare hamburgers – generally do not pose an unacceptable risk of foodborne illness to the healthy customer. However, if a customer is in a group at risk for foodborne illness (see Unit 1), consuming raw or undercooked, potentially hazardous food could possibly increase the risk of illness, sometimes seriously.

In all cases, high-risk customers should be advised, if they ask about or specifically request undercooked food or any potentially hazardous food (or ingredient) that is raw or not fully cooked, of this potential risk .they may want to consult with a physician before regularly consuming these types of food.

Here are general guidelines to follow hen cooking:

Specify cooking time and required minimum internal cooking temperature in all recipes.

Use properly calibrated thermometers with a suitable size probe, accurate to within 2F (1C), to measure food temperatures. Check internal temperatures in several places, in the thickest part of the food. Clean and sanitize the thermometer after each use.

Avoid overloading ovens, fryers, and other cooking equipment. The equipment or oil temperature might drop, and the food might not cook properly. Crowding food also might lead to cross-contamination.

Let the cooking equipment’s temperature recover between batches.

Use utensils or gloves to handle food after cooking and taste food correctly to avoid cross-contamination. The safest and most sanitary way to taste food is to ladle a small amount into a dish. Taste the food in the dish with a clean utensil. When finished, remove the dish and utensil from the area and have them cleaned and sanitized.