The Flow of Food

Most courses addressing the subject of HACCP start their presentation with one or the other of these two fundamental segments:

The Seven Steps of HACCP
The Flow of Food

Often they are not merged with clarity. Essentially, the flow of food is the path that any food item takes from the point of delivery to the facility, to the point of service, to the consumer. We will devote more time to examining this concept in the next module, but a general understanding at this point will prove helpful.

Consider beef stew. First, the ingredients have to be received, then stored. Next, they would be assembled for preparation: the vegetables chopped, the meat cubed, etc. Then the stew would be cooked. Most likely it would be held until requested. If the entire batch was not consumed during the meal, some may be chilled and held for service later. This stew would be reheated and finally, served.

A flow chart is a diagram of the flow of all ingredients contained in a particular recipe. For instance, a restaurant may have a flow chart of its Chili production as well as charts for each of its other menu items. These concepts will be further developed later.

DEFINITION OF A FLOW CHART

The process followed in the preparation of a food from receiving through storage, preparation, cooking, holding, serving, cooling and reheating of that food.

It is against this backdrop (visualizing how food moves through an operation) that the seven steps used to outline the HACCP system are laid out. For instance, when we look at step 1, ‘analyzing the hazards’, we will look at the flow of food to find where hazards may occur.

The name defines the main scope and concept. “Hazard Analysis:” a menu item is scrutinized with the question “What is most likely to go wrong here?” This is analyzing for hazards. Next, points where things can go wrong are identified as “Critical Points.” For instance, in preparing chicken salad, the temperature of the chicken during the de boning process would be a critical point. The word “Control” implies that these critical points can and will be controlled for safety purposes.

The HACCP process follows these seven steps:

Hazard Analysis
Identify the Critical Control Points (CCP) In Food Preparation
Setting Standards for CCPs
Establish Procedures to Monitor CCPs
Taking Corrective Actions
Design a Record-Keeping System
Verification that the System is Working

Step One: Hazard Analysis

This process is used to identify significant hazards. A thorough review of your menu is required to identify items which contain TCS foods such as meats, seafood or fish, eggs, poultry, etc. These menu items should be targeted for HACCP attention.

Hazards may be biological, chemical or physical in nature. For instance, a chicken burrito would quickly be identified as a hazardous food from both a biological and physical standpoint — you need to search for bone fragments when boning the chicken (physical hazard) and to maintain careful temperature control (biological hazard). It may be important to remind persons to return sanitizing chemicals to the storeroom after sanitizing a surface (chemical contamination).

In searching for hazards, think of the entire flow of food — the path each recipe ingredient follows from the point of receiving to the point of sale or consumption. This, actually, is the whole point of HACCP – protecting food throughout the flow of food. This may be summarized in a flow chart, which we will look at later.

Relative degree of risk must be assessed. If a hazard poses a low risk or is unlikely to occur, it need not be addressed in the HACCP plan. This is important to consider — I’ve seen eager committees identify each step in the preparation process as hazardous, no matter how remote the possibility of any problem!

In assessing risk, research, industry opinion and articles may prove helpful. Risk may also partly depend on who will be consuming the food — patients in a nursing home have a lower capacity for resistance. Another factor may be the type of service — holding temperature will not be a hazard if the food is held for only 20 min., but will be more of a hazard if the food is held at the same temperature for a longer period.

Also, it is important to distinguish food safety from food quality. For example, although it is desirable for customer satisfaction to keep lettuce chilled, it is not essential from a food safety perspective.

Step Two: Identify the Critical Control Points (CCP) In Food Preparation

The next step is to identify the critical control points (CCPs) in the flow of food. A critical point is where a hazard can be reduced or eliminated. Each recipe must have at least one CCP to qualify as part of the HACCP system, and each CCP identified must be controlled and monitored.

(The Food Code identifies various regulations according to their degree of importance. The most important would be a “Priority item”. This would, in most instances, be the same as what we refer to here as, “Critical Control Point”.)

Obviously, one would be put in a tenuous situation if, once identifying a point as critical, it was not checked and the results recorded. This would be similar to saying, “Oh, we knew this was important, but didn’t think it was necessary to check on it.”

This is an important point. Committees are quick to identify a CCP, but when faced with the subsequent necessity of monitoring and maintaining records concerning the step, they quickly rethink their opinion. Usually CCPs involve time, temperature, cross contamination or acidity. In determining a CCP, ask these questions:

Does this step involve a hazard of great enough risk to warrant its control?
Is there a preventive measure for this step?
Is control at this step necessary to reduce the risk to the consumer?

Let’s again use the chicken salad as an example in selecting critical control points: each one of these steps is significant and for each one, there is no opportunity for later correction. Each of them has a preventive measure available and, each step, if handled poorly, could result in a significant risk to the consumer. Suggestions for minimizing risk may be written in the recipe. Here, a food preparer may be instructed to pre-chill all recipe ingredients to aid in temperature control.

Step Three: Setting Standards for CCPs

This is quite simple. Most acceptable limits (called “critical limits” by regulatory people) are already well established. For instance, we know that TCS food should not be held at temperatures between 41° and 135°F (5° and 57°C). Final cooking temperatures for various products have already been outlined.

It is important that the standard for each CCP be measurable and clearly written. They should be included on the recipe. Let’s return to our chicken salad.

Step Four: Establish Procedures to Monitor CCPs

Monitoring can be performed either continuously or at varying intervals. Although continuous monitoring is always desirable it is not always possible. (We can’t monitor the temperature of every chicken breast cooked for chicken breast sandwiches.)

If done selectively, acceptable intervals must be established. For instance, it may be determined that the temperature of food held in the steam table should be assessed every 2 hours. In the case of the chicken salad, it may be decided that time in the Danger Zone should be assessed every time it is prepared. Or, if it is prepared daily by the same people, perhaps every third batch should be monitored and recorded. Obviously, the more often a point is monitored, the more quickly a problem is identified and corrected.

However the criteria are established, the purpose of this step should be kept in mind: to determine if the critical control points are being controlled.

Two points: First, the persons doing the monitoring should be very knowledgeable in the importance of the data being collected. They need thorough training. Second, the data should be easily collected and recorded. This helps to discourage “dry lab,” a term used for fabricated data.

Step Five: Taking Corrective Actions

This makes perfect sense. If the standards are not met, what will be done about it? Corrective actions depend on the severity of the situation. For instance, if the chicken was not cooked to 165°F (74°C), return the chicken to the oven and heat until the temperature is reached. If the finished product during holding is discovered to be at 52°F (11°C), and has been there for more than two hours, discard it. Whatever the corrective action, this too, must be clearly identified.

Step Six: Design a Record-Keeping System

Record-keeping is the best insurance for a good system. If records are not kept, people are not encouraged to take the program seriously; if no documentation exists, problems are more likely to reoccur. Records might include such things as temperatures taken during CCP monitoring, recipes showing CCPs, standards used in the establishment and flow charts for foods examined in the HACCP program.

A HACCP flow chart is a simple diagram that follows items for a recipe through each step in the handling process. It is a separate document from a recipe, although both documents identify CCPs and their standards and may or may not also specify corrective actions. The record keeping system should be as simple as possible while maintaining its effectiveness.

Step Seven: Verification that the System is Working

This involves two steps: First it establishes that the standards, etc. are correct and that the proper CCPs have been identified. Second, it requires review of written records to be sure that corrective actions have been taken and that data is collected. There is nothing more disheartening than watching a system that took much effort to design being ignored when the pace becomes hectic.

In summary, the HACCP system is designed to identify problems before they occur and to establish ongoing monitoring systems that control hazards. Although the steps outlined above may seem laborious, they are really quite logical. It must be remembered that HACCP is flexible and can be adapted to the simplest as well as to the most complex system. CCPs are something that can be shared with a child who may be doing his/her own food preparation.

HACCP may also be quite intricate and sophisticated in a food manufacturing plant. What we have presented here is only the most rudimentary overview of this concept, but should serve to broaden understanding in this significant arena.

Receiving

Suppliers

The first rule is: Check out suppliers.

The president of a well known restaurant chain visited his fish supplier. While touring the facility, he noticed a huge tuna resting in a tub of water in the sun. It took very little analysis for him to decide he did not wish to be responsible for the sale of this food. He cancelled his order and closed his account with the supplier.

To whatever extent possible or feasible, visit those from whom you purchase food. Not all markets or storage areas are operated the same; you will gain new confidence, learn a lot and make some changes in your own operation. If nothing else, you will be seen in a new light by your suppliers, for few customers take the time to do this.

Remember, a food pathogen cannot be detected by the senses. An enormous contamination problem can be delivered to you no matter how good the supplier’s setup — he and you may not be able to do anything about it. In the well publicized hamburger E. coli (STEC) outbreak which killed several people in 1994, the restaurant chain carried the burden of the enormous lawsuits, even though it was well known that the meat had become contaminated at the processing plant.

All food must be purchased from an approved source that complies with all local, state and federal food laws — and that’s about as far as you can go. But always visit — you might just find a fish left out in the sun.

Delivery Time

Deliveries should be timed so that the food can be given appropriate attention and proper handling, not during the busiest time of the day. A stack of frozen boxes leaning to one side (as the cardboard thaws, the stack tilts) is sure evidence that the food inside will not be of maximum quality or safety.

Receiving Personnel

A pivotal point of control involves the person in charge of receiving food deliveries. He/she must be trained to look for characteristics or signs of quality issues at the point of delivery that could cause rejection of an item. (a list of such characteristics for common items is located in the Additional Materials section for module 4 in your Course Dashboard.)

The first rule is: Packaging should be undamaged. Obvious signs of tampering or mishandling are cause for immediate rejection.

Special mention needs to be made concerning mollusk and shellfish (clams, oysters, scallops and mussels) because of the distinct risk of Hepatitis A and other foodborne illnesses. These foods must be purchased from sources approved by the FDA and must be received with tags that identify the ‘4 W’s’:

The harvester’s identification number (WHO)
The type of shellfish (WHAT)
The date and site of harvesting (WHEN)
The location where the product was harvested (WHERE)

Instructions to keep the tag on the container until the contents are used must also be present. These tags must be kept on file for a minimum of 90 days from the date the last item was removed from the container.

As we’ve seen, temperature is a most crucial and controllable factor, and receiving personnel should be trained to recognize several visual indicators of temperature abuse. Large ice crystals present in meat products, and large clumps in a bag of vegetables — French fries or peas for example — may indicate thawing and refreezing.

Whether or not there are signs of damaged packing or temperature abuse, selected temperatures should be taken, and these readings must be recorded. This is almost never done except by large corporations who are becoming quite savvy about safety. But it should be: If hamburger is delivered at 47°F (8°C) or above, it must be rejected.

It takes very little effort to determine if that standard has been violated. Food purveyors will quickly become acquainted with your kitchen’s standards. Even if the truck is refrigerated and apparently well monitored, take temperatures anyway. No machine is exempt from malfunction and your responsibility remains in the forefront.

Testing procedures should be consistent. For testing food in a bag (e.g. shredded cheese) wrap the bag around a thermometer. Often a thermometer can be placed between two containers — such as bulk hamburger or hot dogs — to obtain readings. If it is not practical to test packaged items because of the nature of the packaging (such as with bulk milk), it may be possible to sacrifice a random item or two for temperature measurement.

If the food must be unwrapped and penetrated to obtain a correct reading, remember to sanitize the thermometer before and after each use and to rewrap the food carefully. Sample temperatures of all deliveries of time/temperature control for safety foods (TCS)must be taken and recorded for future reference. It is recommended that these records be kept for 6 months to a year. Check with your local health department or corporate risk management or quality assurance department for recommendations. One of the best defenses in a suit for damages is evidence that all reasonable safeguards have been taken.

Some foods which have had their oxygen content reduced may be received. Remember, we stated earlier that lack of oxygen was not a deterrent to bacterial growth; hence, these foods must be temperature controlled just as carefully as any time/temperature control for safety food (TCS). Two bacteria that may be allowed to grow in these foods are Botulism and Listeria. Names for this type of product may include: Modified Atmosphere Packaging (MAP), Reduced Oxygen Packaging (ROP), Controlled Atmosphere Packaging and Vacuum Packaging
(“sous vide”).

Two areas to consider in the matter of temperature record-keeping include “dry lab” (recording temperatures never actually taken —not a good idea), and recording of unacceptable temperatures.

While unacceptable readings should be recorded honestly, there should also be a notation, initialed and dated by the location manager, indicating follow-up procedures taken to correct the situation.

I have often reviewed records that clearly indicated the presence of Danger Zone temperatures with no evidence of what may or may not have been done as a corrective action. The records were simply filed. This reflects not only a very bad system but also an ineffective training program. A lawyer would have a very easy time with this!

Thermometers

Several types of thermometers are available. The most simplistic is known as the bimetallic thermometer. It has a simple shaft made up of two metals (hence: bimetallic) and a dial at the top. It is important that these have an adjustable calibration nut and a dimple marking at the end of the sensing area.

Digital thermometers are available in a variety of price ranges. They provide a digital readout that is very convenient for record keeping. Devices such as thermocouples are available for taking temperatures of very thin foods. For those wanting the newest technology, there are now “point-n-shoot” infrared thermometers. The thermometers instantly measure the surface temperature of a food without penetrating the product.

It should be noted that any thermometer should record a range of 0°F to 220°F (-18°C to 104°C) and should be accurate to within +/- 2 degrees.

Regardless of which type of thermometer is used, two items remain critical:

Accuracy

Did you ever try to argue with a police officer about the accuracy of your speedometer or his radar gun? Neither can you argue with a health inspector — they calibrate their thermometers!

Not all thermometers are adjustable, but the accuracy must be checked to insure integrity of the data. Calibration may be checked at either the cold or hot end, or both. For cold calibration, fill a Styrofoam cup with crushed ice. Allow it to melt until enough water is present to measure the temperature. Immerse the thermometer and adjust to 32°F (0°C).

To measure accuracy at the hot end, take a reading of boiling water — it should be 212°F (100°C). Altitude affects the boiling point of water, so calibration based on your altitude is necessary. There are internet sources for such calculations. Also, be sure the dome of the thermometer is not plastic, which will melt. Taking the temperature of the coffee urn water or other source dependent on its own thermostat is not valid.

If a thermometer is determined not to be accurate, it must be adjusted or discarded. I’ve witnessed a state inspector’s thermometer and a facility’s thermometer differ by 10° — it was not a fun day.

Cleanliness

A thermometer must be clean. A thermometer must be sanitized before and after each use. This may be accomplished best by using an alcohol swab or prep pad — simply wipe the shaft prior to use with a fresh pad and discard the pad after use. Methods not recommended include holding the thermometer under hot water, wiping it on a cloth, or immersing it in a sanitizing solution —unless the solution has been tested for potency.

Storage

Once items have been examined for integrity and temperatures they should be stored quickly, using the first-in-first-out (FIFO) storage system. Food needs to be rotated for quality purposes. A system of color-coded stickers is often used effectively for this purpose.

Food will be placed either in refrigerated, freezer or dry storage units. In all of these areas, food should be stored at least 6 inches above the floor, as good air circulation is imperative for temperature control and quality. Freezers should maintain a temperature of 0°F (-18°C); refrigerators obviously must maintain a temperature below 41°F (colder is preferable — so long as products do not freeze). Dry storage should be cool, dry and ventilated.

In considering refrigeration, specific placement must also be identified. Raw chicken, for instance, must not be stored above produce, as will be discussed later. Consistency of placement also encourages correct usage by personnel, which reduces waste and improves quality.

Once received, acceptable storage times vary (Please visit the Additional Materials for a list of various storage times).

“Real World” Issues

We have been talking largely about commercial or institutional food service operations, but dietitians see all of these issues — on a smaller scale — in their clients’ homes or in their own shopping and purchasing. We can, and should, comment on poor food storage and handling.

When shopping, observe the practices of the store personnel. Are the people in the meat area or deli well-groomed and using good techniques? My husband once had his deli order weighed on a scale with no protective paper — some was even retrieved from the counter top and added to the pile on the scale.

You may also observe meat personnel handling raw product and cooked items — such as shrimp — with the same gloves. One unfortunate employee began to gather the cooked shrimp I was purchasing for a party with the same glove that he had just used to rearrange the hamburger area. He was surprised when I objected.

Preparation

Looking at the bigger picture, let’s review what we have covered so far. First, we established that food safety is indeed an issue, one that is becoming more complex. Then we examined the microbiology of pathogens to understand more fully the factors influencing the problem.

Next we explored personal hygiene issues. In a sense we prepared ourselves for work. Finally, we received the food and stored it away properly.

As we’ve seen, the first two leading causes of foodborne illness are time and temperature abuse and improper hand washing. Now, let’s look closely at what concerns are critical in the preparation area itself. It is in preparation that the third leading cause of foodborne illness — cross contamination — is seen most clearly.

Simply stated, cross contamination is the spreading of contamination from one food to another food. It is very extensive and insidious.

Hands

Hands are a common vehicle for cross contamination. Handling raw meat and then picking up carrots without washing in between and thus potentially transferring pathogens from the meat to the carrots is an obvious example.

Recently, I was preparing Sloppy Joes for dinner. After breaking up the ground meat with my hands, I picked up the spatula to make finer pieces. After this, I went to the sink and washed my hands. OK? No, because the handle of the spatula is now contaminated and will recontaminate my hands as soon as I use it again. Sound familiar? Watch cooking shows, how often does the demonstrator wipe his/her hands on a towel?

Towels

Towels pose an enormous opportunity for cross contamination. Under a microscope, a used towel is seen to harbor tremendous numbers of virulent bacteria. I ask this question in every class: “How long might a towel be used in your operation without being laundered?” The answer varies from four hours to days to “until it looks dirty”.

Towels touch every surface imaginable: counters, equipment, foreheads, plates, spills, hands. Usually damp, they offer a perfect breeding medium for bacteria. Aprons and uniforms offer the same medium when used to dry or wipe the hands.

Cloths

Cloths used for wiping surfaces should be stored between uses in “sani-buckets”— sanitizing solution filled containers. The strength of the sanitizer should be tested frequently, as food particles, light and time decrease the strength present. The Food Code states that “sani-buckets” may be placed above the floor and used in a manner that prevents the food contamination, equipment and food supplies.

Cutting Boards

Cutting boards are another locale of frequent cross contamination. Picture a common scene: raw chicken is cut on a cutting board. It is then rinsed and dried with a cloth towel. Then, vegetables for salad are cut on the same surface. Potential transmission of contamination from the chicken to the vegetables is obvious.

Cutting boards not only need to be washed and sanitized between uses, they need to be clearly designated for one particular type of product. There should be separate boards for raw proteins, cooked proteins, produce and breads.

In a food establishment, this is best accomplished with the use of differently colored boards. At home, it can be somewhat more difficult, but can still be achieved.

Questions often arise about the use of wooden versus plastic boards. Opinions vary but several surfaces are equally acceptable as long as they are cleaned and sanitized correctly. Wood (as long as it is hard wood such as oak, not soft wood such as pine), acrylic or marble are acceptable materials for cutting. Any board must be discarded once the surface is marred sufficiently to make sanitizing impossible. An acrylic board can be sanitized in the dishwasher as long as sanitizing chemicals are present or temperatures are high enough. Home view: a recent survey by the FDA showed 26% of US consumers don’t bother to clean cutting boards after using them for raw meat or chicken.

Dripping Food

Dripping food is another significant opportunity for cross contamination. Raw product should be stored only on the bottom shelf of a refrigerator and only in a drip proof container. Anyone with a refrigerator at home knows what happens when a package of hamburger is placed on a shelf. Blood dripping down onto produce, milk cartons or leftovers is not only distasteful but a serious health problem.

Sometimes what may seem obvious isn’t always obvious to everyone. The best example I have seen is the pan containing both raw chicken and a cooked turkey roll. The chicken had dripped juice into the pan; the turkey roll, which was to be used for sandwiches, was sitting in the juice wrapped in aluminum foil. Cross contamination was not the only concern for this food handler!

Different types of raw products should not be stored in the same container for thawing. In other words, raw chicken should not be in the same pan as raw pork or beef. Juices intermingle and may lead to cross contamination.

Work Surfaces

Work surfaces must be cleaned and sanitized between uses or periodically during use or if product preparation changes. Even stainless steel can be colonized by bacteria. Hands can easily be a vehicle for cross contamination as was outlined previously. Special studies have been done to track Salmonella e. on hands and work surfaces after cracking an infected egg. It is quite a challenge to crack an egg without getting any product on the fingers. And where are the hands usually wiped? If put into a mixer, the bacteria can be found on surfaces several feet away.

Although the opportunities for cross contamination are endless, let’s look at one more example before moving on.

Equipment

Not just knives and spoons, but blenders, food processors and slicers. Equipment that is hard or tedious to clean is the most dangerous. I love to inspect blenders. If I look into a blender that has been cleaned and find a small puddle of water inside, I am certain that the blender has not been disassembled, cleaned and sanitized.

A slicer that looks clean on top but has pieces of food hanging down beneath the blade has not been properly cleaned. One restaurant in the desert area of southern California almost went out of business due to an outbreak of Staph. The cause was eventually traced to a food processor that was used but not disassembled and properly cleaned and sanitized between uses.

We can certainly relate to this issue in the home also! In preparing salmon, I was dotting the surface with pieces of margarine. Salmon – margarine – salmon – margarine. Almost a rhythm, my mind wandered. As I looked again at the process — what had I done? Spread potential contamination from the salmon to the margarine! How easy this can be. Have you ever grilled dinner outside? Frequently, the same platter is used to load up the cooked food as was used to deliver the raw product to the grill.

The household kitchen is far from perfect. Researchers from the University of Arizona demonstrated that E. coli (STEC) is found more frequently on dish towels, sponges and countertops than on toilet rims. Staph and Salmonella were identified in 20% of home dish cloths.

Dish cloths and towels should be changed daily at home and spread flat to air dry during the day. Sponges are even worse. Both sponges and dish cloths can be sanitized by placing them (damp) in the microwave and heating for one to three minutes. Remember, the same principle discussed in the microbiology section applies here: bring the surface to a temperature of 165°F (74°C) to kill pathogens. (Remember to let the sponge/cloth cool before handling.)

Avoid Cross Contamination

Cross contamination occurs when contamination is transferred from one food to another food. To avoid this:

always wash hands carefully during food preparation, especially after handling raw protein products
use different cutting boards for different types of products
clean and sanitize work surfaces and equipment carefully
always store raw product below cooked product, preferably on the bottom shelf and always in a drip-proof container

Thawing

The methods used for thawing product quickly separates those who only pay lip service to food safety and those who believe what they say. Correct thawing of frozen product is a principle of food safety that is violated frequently, even by persons who have been educated in food safety. Here, the application of time and temperature control is paramount: TCS food must be kept out of the Danger Zone at all times. Whichever method of thawing is selected, it must protect either time or temperature. It’s simple, but implementation often meets resistance.

Basically, there are four choices when thawing food:

Thaw food in the refrigerator. This is the preferred method. Although this takes longer, if the temperature of the food is maintained below 41°F (5°C), the opportunity for bacterial growth is controlled. (Remember: bottom shelf, drip proof container.) The length of time required to thaw this way sometimes poses a problem and therefore people often look for alternatives.
Part of the cooking process. Although this sounds strange, we do it frequently. Frozen pizzas, for instance, are often cooked without thawing. The frozen product is placed directly into the cooking device and is exposed to the Danger Zone temperatures. Time in the Danger Zone is limited, however, thus making it a safe process.
In the microwave. Using this process, food is brought directly into the Danger Zone, but for a limited time. The food must be cooked immediately without being held for later use.
Completely submerged under cold running water. This is the one that gives many headaches, for there are a variety of ways to do this improperly — and food handlers are experts at discovering them. First, the food must be completely submerged. Usually, either the food is not submerged at all (the water is only running over the food), or only a portion is submerged. Also, the water must be cold (below 70°F or 21°C) and it must be running. This apparent waste of water offends many people, particularly in areas of the country where water is scarce. This is important, however, to regulate temperature and remove loose food particles.

What is conspicuously absent from this list? The most common practice: letting food thaw at room temperature. Even in a well-run food establishment, this is a disturbingly common practice. In a seemingly almost emotional relationship between the food preparer and the meat (or chicken or fish or whatever), moving food to the refrigerator for thawing has been met with great resistance. Microbes don’t care about feelings, habits or time constraints. They simply follow the principles of growth outlined earlier.

Finally, time is an issue. In a ready-to-eat food, no part of it may be held above 41°F (5°C). If it is a raw product, its total time in the Danger Zone (including preparation for cooking) must not exceed four hours. It should also be remembered that the sink or container used for thawing should be sanitized before and after the thawing process. I’ll never forget the time I saw unpackaged chicken breasts floating around in a sink, waiting to be prepared for dinner. This is not a desirable way to thaw food.

Home presents the same choices. However, there is another, unofficial, suggestion for home use that is quite helpful — as long as a decision can be made about “What’s for dinner?” early in the day. Remove “dinner” from the freezer and microwave on “defrost” for half the time indicated for a full thaw. Remove the food, place it in a drip-proof container and refrigerate. By evening, it will be perfectly thawed without any of the “cooked spots” common with the full microwave thawing process. If that much time is not available in the rush of the morning, the process can be reversed, but some “cooked portions” may be evident.

Cooking

As you have learned, during preparation (working with food prior to cooking) the three primary areas -temperature, hand washing, and cross-contamination must be carefully monitored. Always work with clean hands, gloved if food is not to be cooked, monitor cross-contamination as described and minimize exposure to the danger zone temperatures. A good way to minimize temperature exposure is to prepare food in small batches. Here is an example:

Tuna Salad Sandwiches:

If you are going to prepare tuna salad sandwiches, prepare 25 at a time, not 250.
Place all ingredients to be used in the refrigerator the night before, such as tuna and mayonnaise if preparing tuna salad.
Remember that all foods prepared at room (ambient) temperature, must be cooked immediately or cooled to 41°F (5°C) within four hours.

As we move through the food preparation process, final cooking temperatures need to be addressed, as this is extremely important in the preparation of safe food. The following was prepared from the Food Code.

Cooking Temperatures

Eggs, fish
Internal Temp: 145°F (63°C)
Time Held at this temp: 15 seconds

Roast Beef, roast pork
Internal Temp: 145°F (63°C)
Time Held at this temp: 4 minutes

Ground and mechanically tenderized meat
Internal Temp: 155°F (63°C)
Time Held at this temp: 15 seconds

Poultry, meat stuffed products
Internal Temp: 165°F (63°C)
Time Held at this temp: 15 seconds

Plant products
Internal Temp: 135°F (63°C)
Time Held at this temp: not specified

When cooking in the microwave, foods must be rotated and stirred during the cooking process and heated to a temperature of at least 165°F (74°C) in all parts of the food. Remember to allow the food to stand for 2 minutes after cooking to promote equal temperature distribution.

Review of these temperatures brings us back to a subject introduced earlier: the risk of Salmonella enteritidis in under cooked egg products.

In any food item in which egg will not be fully cooked (such as Caesar’s salad, Hollandaise sauce, French toast or perhaps omelets), pasteurized eggs should be used. Firm cooking of the egg (no runny yellow) is required to assure protection from this organism.

I particularly remember the time my family was on an overnight trip with a camp group. The staff had thoughtfully cooked French toast for breakfast — large thick Texas-style pieces of bread. Even after fully cooking on the outside, the inside remained runny. It’s amazing what you will eat when you are really hungry.

SAFETY POINT

Use pasteurized egg when preparing any under cooked or raw egg product. Reminder: it is illegal to serve under cooked or raw egg to a vulnerable population group.

Preparation of stuffed products, such as stuffed turkey, also poses unique risks. Final cooking temperature of 165°F (74°C) is essential to assure the elimination of pathogens. The temperature must be taken in the geometric center of any food item — in this case, that means the center of the stuffing. Most people take the temperature of the bird. I hear the worst home food poisoning stories after Thanksgiving and Christmas. The safest procedure is to cook stuffing outside the bird.

Date Marking

Date marking is the practice of indicating the date by which a ready-to-eat, TCS food should be used or discarded. This is designed to control the growth of the Listeria bacteria. Retail food establishments that hold these foods for more than 24 hours must clearly mark these products to indicate the date by which these foods must be used or discarded. Foods held at 41°F (5°C) or lower may be held for seven days. If the food was prepared by an inspected food processing plant, the date used must not exceed the expiration date posted by the manufacturer.

Once opened, the food must be dated as above and used within seven days if stored at 41°F (5°C) or lower.

Holding

The best plan for safe food can be ruined at the point of holding foods at the proper temperature. The food may have been handled well and cooked to the correct temperature but if then held within the danger zone, a contamination problem may be introduced. Many foods are never held, and are served immediately. In these cases, there is not a critical control point to be concerned about. However, foods held on a steam table or salad/soup bar would need to be addressed in regards to potential hazards. Below you will find some considerations involving hazards associated with holding foods at the proper temperature.

Hazards When Holding Food

Hazard: Food product placed in unsanitary pan for holding
Consideration: Foods will be placed in clean and sanitized containers for holding Hazard

Hazard: Food is held between 41°F (5°C) and 135°F (58°C).
Consideration: Temperatures will be taken every two hours of foods held to insure proper temperature maintenance

Hazard: Customers/servers contaminate food during holding
Consideration: Foods will be properly protected during holding

Hazard: New food is added on top of old food while holding
Consideration: Any remaining food product will be removed with the used pan. It will be replaced with new product in a clean and sanitized pan.

Hazard: Food is held for extensive periods of time.
Consideration: Food will be prepared in small batches to allow for a limited holding time.

Hazard: Customers may contaminate other customers when obtaining food from self-service bars.
Consideration: Provide clean plates for seconds at self-service bars. Provide separate serving utensil for each food.

As in other steps, temperature control and good personal hygiene remain important. Sneeze guards help to prevent re-contamination of product; separate serving utensils discourage cross contamination.

In dealing with holding times and intervals for measuring and recording temperatures, remember that your plan must reflect your type of service. Although most recommendations may say to take temperatures at 2 hour intervals or that food may be held for 4 hours, these are general industry guidelines. Keeping the firm goal of safe food in mind, create your standards to reflect the intervals needed for your target population. For instance, if food is held on ice, temperatures may need to be measured each hour. If the target population is the elderly, standards may state that food is not to be held more than one hour.

Holding temperatures often are considered CCPs because if handled incorrectly at this step, contamination, if present, would not be reduced or eliminated at a later time. As a reminder, hot holding temperature is 135°. Many establishments choose to hold food at higher temperatures for quality purposes, which is fine. But the minimum temperature is 135°F (58°C). Cold food must be held below 41°F (5°C); some jurisdictions differ on this value, check with your local health department.

Reheating

Time and temperature continue to take center stage in the discussion of one of the most potentially hazardous groups of foods: leftovers. In fact, improper cooling of cooked foods is the most often cited cause of foodborne illness in food establishments (an example of poor time/temperature safeguards).

What we have learned to do at home is usually very wrong, and most food handlers do what they learned at home. Leftovers present a unique problem due to the amount of time they spend in the Danger Zone temperatures. These foods have passed through this zone at least three times in cooking, cooling and reheating. If reheated a second or third time, the exposure greatly increases. It is wisely recommended that foods not be reheated more than once. If a food is contaminated and the process was handled poorly, pathogens often grow to incredibly high numbers.

The general industry standard is to have food products cool from 135° to 41°F (58° to 5°C) within four hours. The Food Code specifies that cooked TCS food shall be cooled to 70°F (21°C) in two hours and 41°F (5°C) in an additional four hours. Coupling the fact that the most rapid growth of bacteria occurs between the temperatures of 70 to 110°F (21 to 43°C), with a lag phase of two hours, it becomes easier to remember these stages of cooling.

To do this, several factors must be considered and controlled.

FACTORS IN REHEATING

Food should be cooled in a manner that reduces cooling time. For examples, transfer hot food into shallow containers with a large surface area. The depth of the food should not exceed 4 in. if it’s a thin liquid such as vegetable soup, or 2 in. if a thick product such as refried beans or chili.

This is easy to understand: which would cool faster — a baked potato at 180°F (82°C) or a plate of French fries at the same temperature? The French fries, of course, due to their larger surface area.

Products such as casseroles or turkeys may also be separated into smaller or thinner portions. Metal containers transfer heat more rapidly than plastic ones.

Stirring decreases cooling time dramatically. Containers of foods may be placed in ice baths to cut cooling time in half. Ice may be added as an ingredient or sanitized containers of ice may be added to the product (and discarded when the product is cool). The industry has developed many new types of equipment for this purpose.

If not using an ice bath, food should be placed immediately in the refrigerator, in a space away from raw food where air circulation is adequate. It should be covered loosely, labeled and dated. Once cooling is complete, the product should be covered securely.

Temperature should be taken during the cooling process to assure safety. These temperatures should be entered in a record-keeping system.

When reheating for service, temperature again is paramount. Food should be reheated quickly to 165°F (74°C). The key word here is quickly — which means in a stove, steamer, microwave (stir frequently) or other cooking device. A steam table is not designed for this purpose.

Final temperature readings of 165°F (74°C) must be reached and recorded. (Remember, 165°F (74°C) kills pathogens.) If not served immediately, hot food must be held at not less than 135°F (58°C). Never mix reheated food with fresh food in the same container.

Although we could produce numerous examples of incorrect handling of leftovers (especially in homes), the best example of an unacceptable procedure in a food establishment involves refried beans. A frequent method, unfortunately, involves removing a large pan of refried beans from a steamtable and placing it directly in the refrigerator for the night. This is a slow process. Literally, the center of the beans was probably in the Danger Zone all night; it takes over 14 hours to cool a product this way.

The next day, the beans are simply placed again on the steamtable for reheating. This process may never bring the food to a temperature of 165°F (74°C) and records are frequently not kept. With the fast pace of change in the area of food safety, however, these procedures are becoming less common.

One additional point for home use. Often we are in a hurry when we reheat food; I know that I am. One minute, maybe two is all I will allow to reheat a food for my own consumption; just enough to take the chill off. This is a huge mistake, as pathogens may remain. Reheat home food thoroughly; boil if possible. Remember to reheat leftovers only once. If a large quantity of food was prepared, stew perhaps, take out only enough of the leftover amount for immediate use. Don’t reheat the whole pot, or the remainder will only have to be chilled again, which is dangerous.

A reminder concerning microwaves and the danger of non-uniform heating. In September 1992, five of six guests at a private dinner party became ill with Salmonella enteritidis. The organism was isolated from a rice dish that had been heated in a microwave oven. Microorganisms may survive in the microwave due to uneven distribution of heat. Be sure food is stirred frequently when cooking or reheating in the microwave.

Leftovers

Always use a thermometer to verify temperatures
Place in shallow container and cool rapidly to 71°F (21°C) within 2 hours, 41°F (5°C) within an additional 4 hours
Label and date product. Hold at 41°F (5°C) or colder
Reheat quickly to 165°F (74°C)
Never mix leftover with freshly prepared food

To summarize, the key areas of food safety in food preparation involve the three primary causes of food contamination:

time and temperature control
personal hygiene and hand washing
cross contamination

All three of these factors play a large role in the entire flow of food: during thawing, preparation, cooking, cooling and perhaps reheating foods. An entire system of food management known as the HACCP program has been designed to insure better control of these issues.

Serving

Now that the food is prepared, how can we prevent contamination during its service? If contamination has occurred, how can we control it? Another interesting aspect involves keeping the food service free from contamination from the consumer. Several considerations are important here.

First, the elementary principle of “keep it hot or keep it cold — or don’t keep it” comes to the forefront. On serving lines, food may be held hot or cold. Steamtables must maintain the temperature of the food above 135°F (58°C). Many times, food is held hotter than this for customer preference, but for food safety, 135°F (58°C) is the minimum. Food held cold, for example salad bars, must be held at less than 41°F (5°C) (some states vary slightly on this). Frequent temperature checks assure safety and provide needed documentation
for these important procedures. The selection of these temperatures takes us back to the beginning of our lessons: TCS foods must be maintained outside the Danger Zone.
Second, good personal hygiene must be practiced by persons serving food, including hand washing and using hair restraints. Obviously no one who is ill should be handling food at any time. To avoid cross contamination, each food must have its own serving utensil.

Self-Service Bars

Self-service bars allow customers to have an impact on the food supply. Therefore, a few considerations on self-service hot or cold bars need to be addressed:

Temperatures must be maintained outside the Danger Zone and should be recorded every 2 hours.
All foods must have their own utensils. Contamination from customers becomes a difficult issue here, as it is hard to restrain persons, especially children, from reaching in and touching food. Some persons even put food back on the bar after putting it on their plate!
Sneeze guards are essential to discourage contamination from sneezing and coughing, and should be set at a reasonable height above the food.
Ice and decorative greens that may be used in the display of the cold items must not later be used in food preparation.
As new food is added to the supply, it should never be added to the top of existing product. Allow existing food supplies to become as low as possible, remove pan and place new pan with fresh food in its place. Remaining food in the first pan may be added to the top of the new pan.
Utensils offered, such as forks and spoons, must be displayed with the handles up to prevent customers from touching the mouth contact surfaces.
Plates and bowls must only be used once. A sign should be placed asking customers to use a fresh plate for seconds. Drinks may be refilled using the same cup, but must be done with a push button in the front of the machine rather than a release lever in the back which may become contaminated by contact with cup rims.
Self-serve stations tend to become messy with customer use. Schedule a person to clean
this area frequently.
Pre-set tableware needs to be protected from contamination. If a table is pre-set, the tableware should be wrapped in a napkin to protect it from exposure. As an alternative, extra tableware settings may be removed when guests are seated. If neither wrapped or removed, unused tableware must be washed after a table has beenused.

Protecting the Server from Customer Contamination

Most efforts are directed at protecting the consumer from the food handler. Careful attention is also needed in the opposite direction.

At all costs, it is imperative that mouth contact surfaces not be touched. Let me explain. Rims of glasses are mouth contact surfaces. When we pick up glasses by the rims, or hold two or three glasses with fingers on each rim, we are touching a mouth contact surface. Literally, it is the same as having that person spit in our hand. When I describe this in classes, people are disgusted and yet they know that by the end of a shift, they may have had 50 to 100 people spit in their hands. It should be noted that this applies to paper cups as well.

Those hands then touch their own noses, mouths, etc., thereby spreading contamination to themselves. The same is true in the more subtle area of napkins. Where are napkins used? On the face and hands, the very areas that harbor contamination. Have you ever observed a bus person clearing and setting tables? Ninety-eight percent of them will handle the dirty glasses by the rims — and then set the new table (your table?) without washing their hands. This is why I suggest that you use a “straw”— as in “drinking straw.” To prevent yourself from having the germs of many people on your water/drink glass.

Keeping your hands out of your mouth is another issue that will do more to prevent colds and other “bugs” than anything else. How simple! Once you start noticing, it will amaze you how pervasive this habit is. Even among medical professionals, people put their fingers in their mouths with incredible regularity.

Resting hands on the face or nail biting are obvious, but more subtle actions are also troublesome. Actions like storing a pen in our mouths because we need both hands free, or licking our fingers to turn pages or count money. Watch at the produce stand — stubborn plastic bags are usually opened by licked fingers.

Remember this: you will never get sick from pathogens that remain on your hands. These can’t be avoided — we touch door knobs, telephones, microwave buttons, etc., or simply shake hands. But if these pathogens gain entrance into your body, they cause illness. With careless habits, this is quickly accomplished.

Your Mom was right…wash your hands before you eat! Think about it, whatever is picked up with the hands and eaten has passed pathogens from the hands to the food and ultimately inside the body. Wash your hands before eating, or using a utensil.

Catering

Since a food producer is responsible for the safety of the food until it is served, off-site delivery poses a special set of challenges. Temperature of the food should be taken at the point of departure from the food facility and again at the point of delivery. Containers for transport must be able to maintain temperatures for as long as necessary. They should be durable and easily cleaned. It may be advisable to obtain the signature of the person receiving the delivery confirming temperatures and to leave a set of instructions for safe food handling.

Implications for Home

What implications does this have for the home? Actually, quite a bit. Keep an eye on length of service. During entertaining or a less-scheduled evening, food may sit at room temperature for hours. For example, how long did the pizza sit out last Friday night?

Speaking of rims of glasses, it may be unrealistic to not touch the rims of the glasses of your family. But, if a person in the family has a cold, don’t touch the rim of their glass! We often assume that if one person in the family gets sick, everyone will get it, but this doesn’t have to be so.

Another good idea to discourage this spread of disease, is to wipe surfaces such as light switches, microwave buttons, faucet handles, door knobs, telephones, etc. with simple rubbing alcohol.

Also, watch for picnic situations. The cumulative time that TCS foods remain in the Danger Zone in these situations can be surprising. My son participates in many swim meets. These last from 7a.m. until dark. Many families would want to have a “pot luck” during the afternoon break at 1 p.m.

My initial reaction would always be, “And where will the food be from 7 a.m. until it is eaten?” In ice chests. What is the temperature of the ice chest in San Diego in July? Good question.

Speaking of pot lucks, “Luck” is actually a very good term here. I loved the church bulletin typographical error that announced that “The pot luck supper will be followed by prayer and medication (instead of meditation)”. The best foods to choose in this type of event are breads, baked desserts and whole fruit, preferably those which need to be peeled. Word of advice: Eat before you arrive. Sorry.

A simple thought about “doggie bags.” How many hours elapse between when the food was placed on your table and when you put it in the refrigerator? Frequently, my husband and I will go to the movies, the coffee shop, the bookstore on our way home from a restaurant. Hours can add up. Not to become obsessive, but more than 4 hours total should be avoided.

Enlightenment does wonders to improve our common sense. Remember, if you never get sick, great. But if you do, some of these issues may be contributing to the problem.

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