At the completion of this module, participants will be able to apply knowledge of sanitation and Good Manufacturing Practices to evaluate controls for in-plant environmental conditions.

Food safety can be controlled through process controls, or those controls that affect the way food moves through the equipment and process to ensure a safe product.

But for those controls to work, they must be accompanied by prerequisite programs - those steps or procedures that control the in-plant environmental conditions that provide the foundation for safe food production. Examples of prerequisite programs are: sanitation, good manufacturing practices (GMPs), training, recall programs and preventive maintenance programs. This section covers sanitation and GMPs.

There are eight broad areas of sanitation that are the most important in ensuring that food products are processed under sanitary conditions. These areas of sanitation apply to food retailers, wholesalers, warehouses, and manufacturing operations of all types.

This area relates to water quality and treatment of water that comes into direct contact with food or food contact surfaces, or that is used in the manufacturing of ice. It also relates to cross connections between potable and non-potable water systems.

Food processors must have adequate supply of potable water at a suitable temperature. In the case of water from wells, state and local officials usually approve well construction and perform periodic, generally annual analysis for total coliform and other water quality properties. Well heads must be sloped away from the well to encourage proper drainage. They should also be sealed to prevent entry of runoff water

There must be properly designed plumbing for water, wastewater, and sewage, with no cross connections which would allow back siphonage. During inspections, water and sewage lines should be traced to find cross connections and dead areas.

Some of the key areas where cross connections occur in processing operations include:

Hose bibs: Typically a vacuum breaker or other type of back flow prevention device is needed to avoid a negative pressure situation. Negative pressure occurs when suction is exerted on the water line, changing the normal positive pressure to negative pressure. So, if a hose is submerged in water, on the floor or in a tank, the dirty water can be sucked up into the potable water supply unless the line is protected with a back flow prevention device.

Wash/thaw/rinse tanks: Water should not enter the tank below the flood rim. Again, if there was a negative pressure situation, the wash water would be sucked up into the potable water supply. In these situations, an air gap of two (2) times the diameter of the water entry pipe (and in no case less than 1") must be provided between the water entry pipe and the rim of the tank to prevent back siphonage.

When ice comes in contact with food or food contact surfaces it must be manufactured and stored in a sanitary manner. For this reason, ice bins must be properly constructed using food grade surfaces. Food and insanitary objects must not be stored in the ice. And the ice must be protected from contamination by employees walking on the ice. The interior of ice machines should be examined to insure that it is clean and no cross connections exist.

This area relates to the design, workmanship, materials, maintenance, cleaning and sanitizing of food contact surfaces, including gloves and outer garments.

Food contact surfaces need to be cleaned and, when necessary for safety, sanitized before use and after interruptions in food preparation or processing. The key point here is that they must be cleaned first, and then sanitized.

Inspectors need to judge the adequacy of cleaning. To do that, they need to look in areas that are difficult to clean, and where product residues may be present. Places such as under the surface of a processing table or below holes that have been drilled in the surface of a table for drainage, where product residues have accumulated, are ideal places for microorganisms to flourish.

Design and installation of equipment so that it can easily be cleaned, plays a big roll in sanitation. Equipment needs to be designed so that there are no rough welds, cracks, or depression that protect bacteria from cleaning and sanitizing compounds. There should be a smooth transition between surfaces, where the different surfaces are bonded. Equipment also needs to be designed so that all of the parts, from the surface to the interior to the framework, can be easily cleaned.

Another concern is equipment that was well designed, but which has outlived its usefulness and has become so scratched and pitted that it can no longer be adequately cleaned. This equipment should be repaired or replaced.

Equipment must be made from materials that can be used for food contact surfaces. Materials such as wood, which is porous and difficult if not impossible to clean, are not an acceptable food contact surface. Food contact surfaces are any surfaces that product comes in contact with. If product comes in contact with a wall, then the wall is a product contact surface and is subject to the same design, maintenance and washing requirements.

Other product contact surfaces are those that employees contact, and then contact the food product, without washing and sanitizing their hands in between. Some examples of these are cooler or rest room door handles, trash containers and raw material packages which cannot be washed or sanitized adequately.

Gloves are also food contact surfaces and need to be made from a suitable material and maintained in a satisfactory condition. Gloves do not solve the sanitation issues associated with product handling. They can transmit bacteria - as well as hands do - but can be cleaned a little easier than hands because they are not as porous. Washing and sanitizing of gloves is equally as important as bare hand sanitation. If gloves are not properly maintained, and develop holes, they can become a source of product contamination.

Storage of gloves while not in use can also be a problem. They must be stored in a location where they will not become contaminated. Cloth gloves should be discouraged, as they are porous and not easily cleaned. Cloth gloves should never be used to handle cooked ready-to-eat product, because they may contribute to re-contamination of the product.

Every food processing facility should have procedures that provide for the adequate cleaning and sanitation of gloves if they are used. The firm's procedures should also provide for clean outer garments for use by processing employees. Street cloths should never come into contact with food products.

This area of sanitation relates to employee practices that are designed to prevent contamination; physical separation of raw and cooked product; and plant design to prevent contamination.

Employee practices:

Proper hand washing and sanitizing can prevent contamination. The purpose of hand washing is to remove organic matter and transient bacteria, so that sanitizing can effectively reduce and eliminate bacteria. But hand washing and sanitizing may not be effective if employees wear jewelry or covering over their fingers, like duct tape or adhesive bandages. Organic matter can lodge between the skin and the jewelry or the tape - where ideal conditions result in subsequent rapid microbial growth, which of course serves as a source of contamination.

Personal items can also contribute to contamination and need to be stored away from production areas. They can harbor filth and bacteria from outside the plant. Storage facilities do not have to be elaborate locker rooms and can even be small closets, as long as it is away from the production area.

Practices such as eating, drinking or smoking in production areas should not happen. That is basic food sanitation. In almost all of these situations, the hands come in close proximity with the nose, and the nose harbors Staphylococcus organisms in about 50% of the healthy population.

Skin contaminants are also a concern. Elbows, arms and other uncovered skin surfaces should not come into contact with food or food preparation surfaces.

Physical separation:

One way to prevent cross contamination is to provide adequate space for processing operations. State and local officials generally review processing plant blueprints before construction with a goal of minimizing spacial problems. Space problems generally occur with the addition of product lines, increased production, and the installation of new equipment.

Raw food materials and finished products must be separated during production and storage to prevent cross contamination. Examples of where cross contamination may occur are contact between live and cooked crabs or an institutional refrigerator used to store raw meat and poultry products as well as finished ready to eat food products. Separation of the raw and finished products must be carefully controlled to prevent contamination of the ready to eat foods. Separate refrigerators for raw materials and finished products is the best solution to this cross contamination concern.

Employee procedures:

Employee handling procedures can also contribute to product contamination. This happens when employees handle non-contact food surfaces and then handle food products without washing and sanitizing their hands.

Food preparation surfaces must be maintained in a clean and sanitary condition. This includes insuring that the food contact surface is not contaminated by actions such as setting containers or raw material packages which have contacted floors onto clean table tops, or contaminating food preparation surfaces with water splash off from floors or other areas of processing equipment.

(4) Maintenance of hand-washing, hand-sanitizing and toilet facilities

This area also includes proper sewage disposal. State and local officials generally approve individual septic systems. Inspections should reveal problems that sewage handling systems might present.

Unapproved sewage disposal systems pose a public health hazard, as they are a direct fecal source. When septic systems are used the system must be closed and drainage fields cannot be open to the environment, including ponds, lakes and estuaries. Well-maintained privies may be an acceptable means of sewage disposal depending upon local regulations. But if they are used, they must be constructed to provide for adequate ventilation, screened to prevent insect entry, and located away from food production areas. Oxidation ponds can be an effective means of treating sewage, but its proximity to the plant may cause it to serve as a fecal source.

Toilets need to be accessible, sanitary and in good repair, with self closing doors that do not open to the processing area. The concern is for air-borne pathogens as well as access of vermin to both areas. Inspections should include flushing each toilet in every plant. Many do not function properly and can allow fecal material to contaminate the floor. If the seal around the toilet does leak, it is easy for an employee to pick up the fecal material on their shoes and transport it into the processing area.

Hand washing and hand sanitizing stations need to be conveniently located. If they are not convenient, they won't be used. But they should not be so close as to present a risk of contamination of the product. There needs to be hot and cold mixed water, soap, and disposable towels or other suitable methods of hand drying such as hot air. The hand washing stations need to be constructed to prevent recontamination. A knee activated valve, automatic electronic valve, or foot activated valve is ideal. Inspections should include testing a number of hand washing stations to insure that they are working properly.

A common practice is the use of sanitizer dips on worktables. The idea here is for the employee to dip their hands or utensils as they become soiled to keep the microbial load down. But under the best conditions, those that assure the proper sanitizer strength, this is not effective because hands and utensils become covered with organic matter that will shield the bacteria from the action of the sanitizer. Under typical conditions, the sanitizer will be used up while oxidizing the organic matter with no remaining sanitizer to inhibit growth. So, these dip stations can actually serve as a source of contamination and should be discouraged.

These two areas relate to protecting food from various microbiological, chemical and physical contaminants such as lubricants, fuel, pesticides, cleaning compounds, sanitizing agents, condensate and others. A few examples are:

Drip and condensate: Drip and condensate can contaminate product and need to be prevented. Steam environments are especially hard to control, and condensate that forms on evaporator pans in coolers can also be a problem where the product is being stored below and is subject to the condensate drip. Listeria has often been associated with the cooler environment.

Ventilation: Ventilation is often used to reduce condensate formation and noxious odors. However, make sure it does not create other problems such as blowing the condensate into the product or blowing dust and other contaminates into the product.

Lighting: With lighting comes the risk of glass breakage and possible contamination of the food product. Light bulbs must be covered with shields or be coated in plastic. Light shields must be intact with end caps in place.

Storage of toxic materials: Certain toxic materials are needed in a plant where food is being processed, for example, cleaning compounds; laboratory chemicals; those used for equipment maintenance; and those necessary in the plants operation, such as food additives. But, any items that are necessary need to be properly labeled and stored away from the processing area in their own designated area. If possible cleaning compounds and other toxic and corrosive compounds should be stored in a locked storage area, which is accessible only to those individuals, trained in their use.

This area relates to the exclusion of persons who appear to have an illness, wound, or other affliction that could be a source of microbial contamination. Processors should have a program to exclude these affected employees from working with and around food products.

Excluding pests such as rodents, birds, and insects which carry a variety of human disease agents is essential to maintaining sanitation of food and food preparation areas.

Primary to pest control is to minimizing the factors that attract the pests, such as debris, unused equipment, product waste and uncut vegetation. Windows, doors and other openings, such as open eves, drainage holes and cracks around plumbing pipes, which lead into the processing facility should be closed, screened or protected (e.g. through the use of air curtains), to prevent the entry of insects, birds, rodents and other pest into the firm. Safe and effective pest control must start outside the plant, with the removal of harborage areas and any food sources such as food waste.

Domestic animals, such as cats used for pest control, and dogs that may be used as guard or companion animals should not be allowed in food production and storage areas. Contamination of food by these animals poses the same risk as contamination by animal pest.

For the most part, compliance with good manufacturing practices and sanitation requirements are the foundation for safe food production. The table that follows takes each of the eight sanitation areas and relates them to specific citations in FDA's 21 CFR Part 110, Good Manufacturing Practice regulations.

Additional guidance on GMPs and requirements for the sanitary production and storage of food products can be found in FDA's "CURRENT GOOD MANUFACTURING PRACTICE IN MANUFACTURING, PACKING, OR HOLDING HUMAN FOODS" 21 CFR Part 110, and in the U.S. Public Health Service, FDA "1999 Food Code".

Chelation - The action of an organic compound attaching itself to the water hardness particles and inactivates them so they will not combine with other material in the water and precipitate out.

Cleaning - A process which will remove soil and prevent accumulation of food residues which may decompose or support the growth of disease causing organisms or the production of toxins.

Deflocculation or Dispersion - The action which groups or clumps of particles are broken up into individual particles and spread out suspended in the solution.

Detergents - Cleaning agents or compounds that modify the nature of water so that it may efficiently penetrate, dislodge and carry away surface contamination.

Disinfectant - usually a chemical agent which destroys germs or other harmful organisms or which inactivates viruses. Most commonly used to designate chemicals that kill growing forms but not necessarily resistant spore forms of bacteria, except where the intended use is specifically against an organism forming spore or a virus, in which instance, the spores too may be killed or the virus inactivated.

Dissolving - The reaction which produces water soluble materials from water insoluble soil.

Emulsification - is a physical action in which fats are mechanically broken up into very small particles which are uniformly suspended in a solution.

Penetration - The action of liquids entering porous materials through cracks, pin holes, or small channels.

Peptization - Physical formation of colloidal solutions from partially soluble materials.

Precipitation - Soften water by precipitating out the hardness.

Rinsability - The action which will break the surface tension of the water in the solution and permit the utensil to drain dry.

Sanitizing - a process which destroys a disease causing organisms which may be present on equipment and utensils after cleaning.

Sanitizing Agent - is an agent that reduces the number of bacterial contaminants to safe levels, as may be judged by public health requirements. Chemical sanitizer used shall meet the requirements of 21 CFR 178.1 01 0.

Saponification - the chemical reaction between an alkali and a fat in which soap is produced.

Sequestering Agents - compounds which will react with certain ions to form relatively stable, water soluble complexes. Polyphosphates are often used in detergent formulations to prevent precipitation.

Sequestration - The action of an inorganic compound attaching itself to the water hardness particles and inactivates them so they will not combine with other material in the water and precipitate out.

Soap - is a sodium or potassium salt with a long chain organic acid.

Soil - matter out of place.

Sterilization - implies the complete destruction of all microorganisms.

Suspension - The action in which insoluble particles are held in solution and not allowed to settle out onto the utensils.

Synergism - A chemical used as a builder with a soap or detergent, which results in a detergency which is greater than the total detergency of the chemical and the soap if they were used independently.

Cleaning is a process which will remove soil and prevent accumulation of food residues which may decompose or support the growth of disease causing organisms or the production of toxins.

Listed below are the five basic types of cleaning compounds and their major functions:

1. Basic- Alkalis - Soften the water (by precipitation of the hardness ions), and saponify fats (the chemical reaction between an alkali and a fat in which soap is produced). .

2. Complex Phosphates - Emulsify fats and oils, disperse and suspend oils, peptize proteins, soften water by sequestering, and provide rinsability characteristics without being corrosive.

3. Surfactant - (Wetting Agents) Emulsify fats, disperse fats, provide wetting properties, form suds, and provide rinsability characteristics without being corrosive.

4. Chelating - (Organic compounds) Soften the water by sequestering, prevent mineral deposits, and peptize proteins without being corrosive.

5. Acids - Good at mineral deposit control; and soften the water.

When considering a good cleaner the following properties should be considered:

1. Quick and complete solubility.

2. Good wetting or penetrating action.

3. Dissolving action of food solids.

4. Emulsifying action on fat.

5. Deflocculating, dispersing, or suspending action.

6. Good rinsing properties.

7. Complete water softening power.

8. Noncorrosive on metal surfaces.

9. Germicidal action.

10. Economical to use.

The factors that affect cleaning efficiency are:

1. Selecting the right cleaner for the job.

2. Increasing the temperature of the cleaning solution so that the strength of the bond between the soil and surface is decreased, the viscosity is decreased, and the solubility of the soluble materials and the chemical reaction rate is increased.

3. Increasing the turbulence "elbow grease".

4. Increasing the time the cleaner has contact with the surface needing to be cleaned.

5. Increasing the concentration. Concentration is the least effective variable to change in cleaning.

The cleaning operation:

1. Prewash - the removal of gross food particles before applying the cleaning solution. This may be accomplished by flushing the equipment surface with cold or warm water under moderate pressure. Very hot water or steam should not be used because it may make cleaning more difficult.

2. Washing - the application of the cleaning compound. There are many methods of subjecting the surface of equipment to cleaning compounds and solutions. Effectiveness and the economy of the method generally dictates its use.

1. Soaking - immersion in a cleaning solution - The cleaning solution should be hot (125 degrees Fahrenheit) and the equipment permitted to soak for 15 - 30 minutes before manually or mechanically scrubbed.

2. Spray method - spraying cleaning solution on the surface. This method uses a fixed or portable spraying unit with either hot water or steam.

3. Clean-in-Place systems (C.I.P.) - is an automated cleaning system generally used in conjunction with permanent-welded pipeline systems. Fluid turbulence in the pipeline is considered to be the major source of energy required for soil removal.

4. Foaming - utilizes a concentrated blend of surfactant developed to be added to highly concentrated solution of either alkaline or acid cleaners. It produces a stable, copious foam when applied with a foam generator. The foam clings to the surface to be cleaned, which increases contact time of the liquid with the soil, and prevents rapid drying and runoff of the liquid cleaner, thereby improving cleaning.

5. Jelling - utilizes a concentrated powdered-jelling agent which is dissolved in hot water to form a viscous gel. The desired cleaning product is dissolved in the hot gel and the resulting jelled acid or alkaline detergent is sprayed on the surface to be cleaned. The jelled cleaner will hold a thin film on the surface for 10 minutes or longer to attack the soil. Soil and gel are removed with a pressure warm water rinse.

6. Abrasive type powders and pastes - are used for removing difficult soil. Complete rinsing is necessary and care should be taken to avoid scratching stainless steel surfaces. Scouring pads should not be used on food-contact surfaces because small metal pieces from the pads may serve as focal points for corrosion or may be picked up in the food.

3. Rinsing - the removal of all traces of the cleaning solution with clean potable water.

4. Sanitization - a process either by using heat or a chemical concentration that will reduce the bacterial count, including pathogens, to a safe level on utensils and equipment after cleaning.

The primary reason for the application of effective sanitizing procedures is to destroy those disease organisms which may be present on equipment or utensils after cleaning, and thus prevent the transfer of such organisms to the ultimate consumer. In addition, sanitizing procedures may prevent spoilage of foods or prevent the interference of microorganisms in various industrial processes which depend on pure cultures.

There are two generally accepted methods of providing for the final sanitization of a utensil after effective removal of soil, heat and chemical.

1. Heat

1. Hot water - an effective, non-selective sanitization method for food-contact surfaces; however, spores may remain alive even after an hour of boiling temperatures. The microbicidal action is thought to be the coagulation of some protein molecules in the cell. The use of hot water has several advantages in that it is readily available, inexpensive and nontoxic. Sanitizing can be accomplished by either pumping the water through assembled equipment or immersing equipment into the water. When pumping it through equipment, the temperature should be maintained to at least 171 F (77 C) for at least 5 minutes as checked at the outlet end of the equipment. When immersing equipment, the water should be maintained at a temperature of a least 171 F (77C) or above for 30 seconds. The water temperature at the manifold for mechanical warewashing equipment must be: single temperature stationary rack = 165 F (74 C), all others = 180 F (82 C).

2. Steam is an excellent agent for treating food equipment. Treatment on heavily contaminated surfaces may cake on the organic residues and prevent lethal heat to penetrate to the microorganism. Steam flow in cabinets should be maintained long enough to keep the thermometer reading above 171 F (77 C) for at least 15 minutes or above 200 F for at least 5 minutes. When steam is used on assembled equipment, the temperature should be maintained at 200 F for at least 5 minutes as checked at the outlet end of the assembled equipment.

2. Chemical

There are a wide variety of known chemicals whose properties destroy or inhibit the growth of microorganisms. Many of these chemicals, however, are not suitable for use on food-contact surfaces because they may corrode, stain or leave a film on the surface. Others may be highly toxic or too expensive for practical use. When looking for an approved sanitizer the label must include:

1. EPA registration number.

2. States that the product may be used on food contact surfaces.

3. Does not require a potable water rinse.

4. States that the product will sanitize. If a product is a detergent/sanitizer, it must also make the claim to clean.

The most commonly used chemical sanitizers for food contact are:

1. Chlorine and its compounds combine indiscriminately with any and all protein and protoplasm. The mode of bactericidal action is thought to be the reaction of chlorine with certain oxidizable groups in vital enzyme systems.

2. Iodophors are soluble complexes of iodine combined usually with non-ionic surface-active agents, loosely bound.

3. Quaternary Ammonium Compounds are compounds that are synthetic surface-action agents. The most common ones are the cationic detergents which are poor detergents but excellent germicides. In these compounds, the organic radical is the cation and the anion is usually chlorine. The mechanisms of germicidal action is not completely understood, but is associated with enzyme inhibition and leakage of cell constituents.

Factors affecting the action of chemical sanitizers:

1. Contact of the sanitizer - in order for a chemical to react with microorganisms, it must achieve intimate contact.

2. Selectivity of the sanitized - certain sanitizers are non-selective in their ability to destroy a wide variety of microorganisms while others demonstrate a degree of selectivity. Chlorine is relatively non-selective; however both iodophors and quaternary compounds have a selectivity which may limit their application.

3. Concentration of the sanitizer - in general, the more concentrated a sanitizer, the more rapid and certain its actions. Increases in concentration are usually related to exponential increases in effectiveness until a certain point when it accomplishes less noticeable effectiveness.

1. A chlorine solution shall have a minimum temperature based- on the concentration and pH of the solution as listed in the following chart;

2. Iodine solution shall have a:

1. Minimum temperature of 24° C (75° F),

2. pH of 5.0 or less or a pH no higher than the level for which the manufacturer specifies the solution is effective,

3. Concentration between 12.5 mg/L and 25 mg/L.

3. Quaternary ammonium compound solution shall;

1. Have a minimum temperature of 24° C (75° F),

2. Have a concentration as specified under the requirements specified in 21 CFR 178.1010 and as indicated by the manufacturer's use directions included in the labeling, and

3. Be used only in water with 500 mg/L hardness or less or in water having a hardness no greater than specified by the manufacturer's label.

4. Temperature of solution - all of the common sanitizers increase in activity as the solution temperature increases. This is partly based on the principle that chemical reaction in general are speeded up by raising the temperature. However, a higher temperature also generally lowers surface tension, increases pH, decreases viscosity and effects other changes which may enhance its germicidal action. it should be noted that chlorine compounds are more corrosive at high temperatures, and iodine tends to sublime at temperatures above 120 degrees Fahrenheit.

5. pH of solution - the pH of the solution exerts a very pronounced influence on most sanitizers. Quaternary compounds present a varied reaction to pH depending on the type of organisms being destroyed. Chlorine and iodophor generally decrease in effectiveness with an increase in pH.

6. Time of exposure - sufficient time must be allowed for whatever chemical reactions that occur to destroy the microorganism. The required time will not only depend on the preceding factors, but on microorganism. populations and the populations of cells having varied susceptibility to the sanitizer due to cell age, spore formation, and other physiological factors of the microorganisms.

Dishwashing machines belong to one of two categories: the hot water or chemical sanitizing type. Standards for manufactures's of these dishwashing machines are provided by NSF International as Standard Number 3. Part of the standard requires:

1. Hot water sanitizing machines shall specify the following on a permanently attached data plate:

1. The minimum temperature of the wash water in the tank (unless numerically indicated at the location of temperature indicating device);

2. The minimum temperature of pumped rinse in the tank, if applicable (unless numerically indicated at the location of temperature indicated device);

3. The minimum temperature of the final sanitizing rinse at the spray arm manifold (unless numerically indicated at the location of temperature indicting device);

4. The minimum and maximum pressure in the final sanitizing rinse line with the rinse in operation (not required for machines with a pumped final sanitizing rinse);

5. The minimum wash and final sanitizing rinse cycle times (stationary rack machines only);

6. The maximum conveyor speed (conveyor machines only).

2. Chemical sanitizing machines shall specify the following on a permanently attached data plate:

1. The minimum temperature of wash water in the tank (unless numerically indicated at the location of temperature indicating device);

2. The minimum temperature of pumped rinse in the tank, if applicable (unless numerically indicated at the location of temperature indicating device);

3. The minimum temperature of the chemical sanitizing rinse (unless numerically indicated at the location of temperature indicating device);

4. Type of chemical sanitizer and minimum concentration in the chemical sanitizing rinse;

5. The maximum and minimum pressure in the chemical sanitizing . rinse line with the rinse in operation (not required for machines with a pumped final sanitizing rinse);

6. The minimum wash and chemical sanitizing rinse cycle times (stationary rack machines only);

7. The maximum conveyor speed (conveyor machines only).

• For glasswashing machines using chlorine sanitizing solution, the minimum final rinse temperature specified by the manufacturer shall be at least 75° F (24° C).

The following are general requirements for a successful dishwashing operation

1. Selection of the proper dishwashing machine, correctly sized to suit the needs of the particular operation.

2. Properly sized and installed water heating equipment to supply the dishwashing operation.

3. Effective layout of the equipment and utilization of labor.

4. Training of the operator in the use and the maintenance of the equipment and the correct use of detergents and/or other chemicals used in the dishwashing process.

5. Managerial surveillance of the operation to determine that the dishwashing procedure is carried out properly by the trained personnel.

6. A protected dish handling and storage system to assure clean dishes when required for use.

The majority of commercial spray-type dishwashing machines on the market today will do the job required of them. The major problems with this type of equipment are operational and require periodical surveillance. Selection of a particular machine for a given operation requires knowledge of the demands to be placed on the machine, type of utensils to be washed, quantity of utensils at peak periods, etc. A properly sized dishwashing machine engineered to conform to the requirements of NSF International standard 3, properly installed and maintained will do a satisfactory job.

When preparing to check a dishmachine begin by reviewing the operational requirements listed on the data plate of the machine. Then check the following:

• Scrape trays clear.

• Conveyor-type machines-curtains intact, clean and in proper position.

• Conveyor speed according to manufacturer's specifications.

• Overflow standpipe in place and not blocked or leaking.

• Wash and rinse pump inlet unobstructed.

• Tank interior clear of buildup of lime, food soils, etc.

• Wash and rinse nozzles clear of obstructions and lime deposits.

• End caps in place on wash and rinse arms.

• Rinse line strainer clear.

• Wash and rinse thermometers accurate or properly calibrated.

• Pressure regulator functioning properly.

• Flow pressure 15 to 25 pounds per square inch (psi) (where required).

• Building water pressure adequate.

• Rinse arm nozzle alignment correct.

• Dishes properly racked.

Proper sanitization in a dishmachine depends on heat accumulation from washing, power rinsing (on some types of machines), and final rinsing. Therefore, each of these cycles must be operating at the proper temperature. To insure this, the following should be determined:

• No lime deposits in heating elements.

• Machine tank gas heater jets not obstructed.

• No excessive ventilation draft in the removal of steam and condensation.

• Maximum-registering, mercury-filled thermometers and thermo-labels (paper thermometers that change color from silver to black when reaching specified temperatures) may be used to confirm the effectiveness of heat sanitization.

• The maximum-registering, mercury-filled thermometer, to give accurate readings, should be attached (rubber bands or clips may be used) in a vertical position. It should also be taken out of any case or guard when used. Thermo-labels are attached by pressure-sensitive adhesive tape preferably on a clean dry china plate. A thermometer can be attached at the gage cock to check the calibration of the final rinse thermometer without removing the final rinse thermometer sensing bulb. However, the thermometer to be attached should have an immersion mark on it and must have a special connection that will allow movement of the stem through the opening presented when the valve is turned on. The sensor must be inserted into the flowing stream of water or serious errors in readings can occur since cooling will take place between the rinse flow line and the thermometer location. Check the thermorneter that is being used as the calibrating thermometer. Immerse it in the hot water to the immersion mark on the thermometer and take a comparison reading. There will be a difference in reading if the bulb is not immersed to this depth each time. Temperatures must be checked with the rinse activated and water flowing in the line.

• As water falls through space after leaving the rinse spray arms, the drop in temperature is rapid. The temperature developed at the dish surface can be 10° F. to 20° F. lower than the temperature in the manifold. Therefore, a reading on the maximum-registering thermometer of at least 160° F. or a color change in thermopaper at 160° F. should be acceptable.

• Unless the machine is used just prior to testing, run the machine through at least two complete wash and final rinse cycles before taking readings.

• Close adherence to manufacturer's specifications as listed on the machine data plate is very important.

The following is a list of common problems experienced in dishwashers together with suggested remedial action

Upon completion of this module, the participants will:

• Have an understanding of the use of cooking to achieve the death of microbes.

• Have an understanding of the factors involved in the destruction of microbes by cooking.

• Recognize various cooking methods and the controls necessary to assure proper reduction of hazards through the cooking process.

1. PURPOSE OF COOKING

Cooking of meat and poultry products changes the foods' color and texture, halts enzymatic action and generally makes food more palatable; however, from a safety standpoint, the most important purpose of heating is to kill or inactivate spoilage and pathogenic organisms.

2. TYPES OF HEATING

This module will discuss the various types of cooking methods and the control procedures to assure the elimination of pathogens; however first let's discuss the way heat is transferred in the cooking processes.

3. WHAT AFFECTS HEAT RESISTANCE IN BACTERIA

Understanding the penetration of heat into a cooked food is the easy part. Somewhat more difficult to understand is how this heat affects microbes in the food. Not all species of microbes die at the same rate as the result of heat application. In addition, the same species of microbes contained in different types of foods may have very different resistance to heat due to the nature of the food product in which they are contained or their previous growing conditions. There are a number of factors that influence the resistance of bacteria to heat applied during the cooking process and we will discuss some of them.

3.1 NATURE OF BACTERIA (psychrophiles/mesophiles/thermophiles)

Before we discuss the effect of heat on microbes, you should understand that different microorganisms have significantly different tolerance to heat. Because of their very nature, microbes can grow over a wide range of temperatures from about 14° F to 194° F. Microbes are grouped into three categories based on their temperature growth ranges as shown in the table below.

Psychrophiles, which includes such organisms as Listeria monocytogenes can live and grow at refrigerated temperatures. Mesophiles grow at temperatures between 50° F and 110° F; while thermophiles grow at elevated temperatures of 110° F to 194° F. The following table shows the temperature growth ranges of specific pathogens.

Source: Second Edition of the FDA Fish and Fisheries Products Hazards and Control Guide, 1998.

Most, but not all, of the microorganisms of public health concern in foods are mesophiles and their optimum growth temperature corresponds to the human body temperature. Typically, the higher the temperature (within the growth range), the more rapid the growth of the organism. This can be explained by the fact that growth is catalyzed by enzymatic reactions. The rule of thumb is that for every 18 degrees of F increase in temperature the catalytic rate of an enzyme doubles.

It is not only temperature that affects the rate of growth or destruction of organisms, but also the time of exposure to a set temperature. The goal is to reduce the amount of time that a food is exposed to optimum growth temperatures. Therefore, it is recommended that food products be maintained either above 140° F or below 41° F. Later we will discuss minimizing the time in the 'Danger Zone' by rapid cooling procedures, but for now we will concentrate on the reduction of microbes by cooking. Cooking easily destroys the vegetative cells of psychrophiles and mesophiles, however thermophiies are much more heat resistant.

3.2 SPORES VS. VEGETATIVE CELLS

Since we have mentioned vegetative cells, lets discuss another inherent characteristic of some bacteria. The active growing stage of microbes is known as the vegetative stage of the organism. Vegetative bacterial cells are much more sensitive to heat than are spores. However, many vegetative cells are resistant to cold temperatures, and may survive freezing.

Spores are a dormant stage of the bacteria, and are much more resistant to heat than the vegetative stage. Some spores can survive boiling water for more than an hour, they also hold up well under freezing, and may resist some sanitizing compound. A spore usually develops from a vegetative cell during unfavorable environmental conditions. This is the cell's way of surviving such adverse conditions. Spores, themselves, do not reproduce and grow and would be of little concern if they could never grow again. However, like plant seeds, spores can germinate and grow. Ironically, it takes adverse conditions, such as the thermal shock that occurs during the cooking process, to cause these cells to germinate and once again grow into vegetative cells. These cells possess all of the pathogenic characteristics of the originating cells.

3.3 TYPE OF FOOD

Characteristics of some foods influence how heat affects the pathogens that may be contained in them. For example, pathogens are more easily destroyed in foods having a low pH (acidic). Also, moisture in a food product improves heat penetration and aids in the destruction of pathogens. On the other hand, sugars or oils in a food can surround bacteria and can insulate and protect them from heat.

3.4 GROWING CONDITIONS

A pathogen that is already under stress is easier to destroy by the heating process. For example, microbes that have grown under unfavorable water activity conditions are easier to destroy by heat. However, sometimes changes in the environmental conditions can favor the survival of microbes. For example, in a 1978 experiment, beef rounds dry roasted to an internal temperature of 145° F were found to have Salmonella on their dry surface that survived the cooking process. (S.J. Goodfellow and W.L. Brown "Fate of Salmonella Inoculated into Beef for Cooking.") It was postulated that this resistance was due to rapid dehydration, which in turn resulted in the Salmonella having a higher resistance to heat.

3.5 HUMIDITY OF THE COOKING VESSEL

Moisture is an excellent conductor of heat, and therefore its presence in a high humidity oven or steamer can greatly increase heat penetration and cooking. To demonstrate, you can place your hand in a dry oven at 350° F, and although you will feel the heat, you would not be burned. However, if you placed your hand in steam from boiling water (212° F), you would immediately receive a severe burn. Moisture or humidity in an oven or other type of cooker has a significant impact on heat transfer. Many cooking processes require either the introduction of moisture into the cooker, or sealing of the container in which the food is cooked to prevent the escape of moisture which is already present. For example, a browning bag which seals moisture in significantly reduces the cooking time for oven roasted turkey. If these required steps are not adhered to, then the cooking process may not achieve the kill step indicated for the recipe.

3.6 WATER ACTIVITY

Bacteria need water as well as food for growth and development. Water in a food product may be freely available, or it may be bound by sugar, salt or other ingredients in the food, and not be available to microbes. The availability of water is described as water activity. Water- activity is measured on a scale of 0 to 1.0 with 1.0 being equal to distilled water. The lowest water activity value at which pathogens will grow is 0.91; however, toxin production can occur at a water activity as low as 0.86.

Although foods with a high water activity level allow for optimal bacterial growth, heat penetration in these foods can be faster because of their moisture content, allowing for faster killing of pathogens contained in them.

3.7 EFFECT OF pH

Most bacteria grow best in a medium that is neutral or slightly acidic, and the growth of most bacteria are significantly inhibited in very acidic foods. pH is measured on a scale of from 0 to 14.0 with 7.0 being exactly neutral. pH levels from 7.0 to 14.0 are basic while those below 7.0 are said to be acid. Foods having a pH above 4.6 are considered to be low acid foods, and their pH will not inhibit pathogen growth. Meats and poultry are low acid foods. Foods that have a pH range of 4.6 or below are considered high acid foods. Tomatoes and citrus fruits and a variety of prepared foods such as mayonnaise fall into this category.

High acid foods are seldom the vehicles for pathogens; in fact many foods are acidified to prevent the growth of undesirable microbes. However, it should be pointed out that the pH or 4.6 is not an absolute barrier to pathogen growth. Some pathogens are more resistant to low pH than others. For example E. coli has a pH tolerance range of from 4.0 to 9.0, and E. coli 01 57:H7 in apple juice with a pH below 4.6 has resulted in foodborne illness outbreaks. pH is especially useful in preventing the germination of spores that are not destroyed by most retail cooking process.

3.8 CUMULATIVE EFFECTS OF GROWTH LIMITING FACTORS ON LETHALITY

There are many factors which affect the growth or destruction of microorganisms in food products. When several of these factors exist at the same time in a food product, they can have a synergistic effect on limiting the growth of microorganisms. For example, the combination of a low pH as well as a low water activity can have a cumulative effect on destruction of microbes during cooking. These same factors (barriers) can also prevent pathogen growth in a cooked food. By applying multiple barriers to a single food product, a higher degree of food safety is assured.

4. THERMAL DEATH CURVES

To understand some of the requirements for cooking of meat and poultry, it is important to know some of the concepts of how microorganisms are destroyed by heat. The destruction of microorganisms by heat is a factor of both time and temperature. Microbes in a food subjected to heat do not die all at the same time. As with any living organism, the weaker cells and those subjected to greater stress die first. Generally, the longer organisms are subjected to heat, and the higher the temperature to which they are subjected, the more of them will die. A typical graph showing the death of microorganisms from cooking is a straight-line graph.

Foodborne Illnesses fall into two categories, the first being an infection and the second being an intoxication. The microorganisms that cause infection and intoxication are all pathogens, but differ in how they affect the body.

Foodborne infections result when-viable pathogens are ingested and attack the host cells. As with any infection, the organism requires time to multiply, therefore the onset of symptoms is rather slow. A common symptom of this type of foodborne illness is fever. Salmonellosis is an example of a foodbome infection. In addition, the illness caused by C. perfringens falls under the foodbome infection classification.

Foodborne intoxication is caused when a specific pathogen grows and produces either an enterotoxin, a toxin contained within the bacterial cell or an exotoxin, which is a waste product of the cell, that is released into the food or the gut of the host. When foods containing either type of toxin are consumed, it is not the organism that causes the illness, but instead, the illness is the result of the toxin. The onset of this type of food illness is much more rapid than a foodbome infection, and a fever does not normally occur in the host. An example is the foodbome intoxication caused by S. aureus toxin.

The critical limits for cooking meat and poultry are the minimum temperatures that are found in the FDA Food Code, 3401.11 (A) (2) or 3-401.12, and USDA Title 9 Code of Federal Regulations part 318.17 or 318.23. The regulatory limits set by USDA allows for altemative.cooking procedures if they are validated to meet the Food Safety and Inspection Service (FSIS) lethality performance criteria of a 5-decimal log reduction of Salmonella within the product. Production requirements for roast beef were established in 1977 and 1978 following several outbreaks of Salmonella foodborne illness. The requirements covered time, temperature, and in some cases, relative humidity.

The FDA Food Code places emphasis on time and temperature as a unit. Previous model codes placed very little significance on this relationship, however, with the new science of today, and our knowledge of emerging pathogens as well as factors contributing to foodborne illness, it is imperative that time and temperature be considered together. The FDA Food Code incorporates the practical application of this principle by integrating it into the model for states to adopt as state laws and regulations.

Most of the regulatory requirements used by USDA and FDA for time and temperatures are designed to destroy Salmonella, and are based on a 1978 Goodfellow and Brown study "Fate of Salmonella inoculated into beef for cooking." Based on that study, the parameter of 165° F or above for 15 seconds for cooking poultry provides a 7D reduction. Cooking at 155° F for 15 seconds provides a 5D reduction, while cooking at 145° F cook for 15 seconds provides a 3D cook.

Some cooking processes are based on the destruction of pathogens other than Salmonella. For example, the process for cooking ground beef, in addition to providing a 5D reduction in Salmonella, also provides an 8D reduction in the number of E. coli. The cooking process for pork is based on the destruction of trichina.

The following are some of the important factors in the cooking process.

• The time the food is being heated to the cook temperature (come-up).

• Time the food is held at the cook temperature.

• The time during cooling (come-down).

In this part we will explore the requirements, and the control's necessary for hot holding, cooling, cold holding, reheating, time as a public health control and temperature measuring.

Upon completion of this part, the participants will:

• Understand the concepts and principals of hot holding and the microbiological implications of not maintaining foods at the proper temperatures.

• Understand the reasons and methods for rapid cooling to a safe temperature and the effect of cooling on the growth of microbes.

• Have an understanding of the equipment and methods necessary for proper cold holding, the difference between cold holding and cooling.

• Understand the requirements for reheating.

• Understand the requirements for using time as a public health control.

• Understand various methods of measuring product temperatures.

Many foods are cooked for immediate consumption. However, some foods may be prepared in advance of service. Not all pathogens are killed during the cooking process, and even if they were, subsequent handling can reintroduce pathogens that may grow in foods if proper temperatures are not maintained. It is critical to either hold these foods at safe elevated temperatures, or rapidly cool to safe cold temperatures. Cooling and cold holding will be discussed later in this module. Let's turn our attention now to the procedures used for and the controls necessary for the hot holding of food products.

Foods may be taken directly from the cooking process to hot holding. In other instances, a food product is cooked, cooled, then reheated and placed into hot holding. It is crucial for holding that the minimum product temperature of 140° F be maintained. The danger during hot holding is that spores of organisms such as C. perfringens will germinate and begin rapidly reproducing.

HOT HOLDING

The FDA Food Code specifies that potentially hazardous foods are to be held at 140° F or above. An exception to this rule is allowed for whole beef roasts and corned beef. It allows a minimum hold temperature of 130° F if they have been cooked or reheated to the temperatures and time specified for these products in the Food Code under Section [3.402.1 1 (13)]. See the following two tables.

All parts of the food must be heated to the temperatures and held for the time that corresponds to that temperature as specified below.

For several reasons, the food manager may wish to hold food products hot enough to serve, but below safe food holding temperatures. An example is maintaining prime ribs at below safe temperatures to assure that they are kept rare. Other reason may include maintaining marginal temperatures to prevent drying of the food, over cooking it, or the development of a film on soups or gravies. It is therefore important to attempt to educate food managers to assure that they understand that it is critical to maintain proper hot hold temperatures. It is important that decisions about holding temperatures are based on food safety and not on food presentation. If presentation is important, these foods should be prepared for immediate service.

There are several methods and types of equipment used in the hot holding of foods. The most common use of hot holding is in the cafeteria style serving of foods. Meats and poultry served from cafeteria or buffet lines can be placed in typical hot hold pans on steam tables, in bain-maries, storage units, etc. Regardless of the method employed, it is important to remember that it is not the thermostat setting of the hot holding equipment, but the temperature of the food that must be controlled. Since there may be varying temperatures in a hot holding unit, moist and dry products may maintain heat differently.

Remember that some of the equipment designed for hot holding of food should not to be used for heating. This equipment is designed to hold temperatures that have already been reached, and may not have sufficient heating capacity to adequately reheat food products that have already been cooled. Cold foods placed in food equipment could remain too long in the temperature danger zone, allowing for the growth of pathogens. Other considerations in hot holding should include:

• The amount of food placed into hot holding equipment must not exceed its capacity.

• The occasional stirring of food in hot hold to assure uniform temperatures. Temperatures in the top of deep containers can cool to favorable growth conditions. Occasional stirring of these containers will promote temperature uniformity.

• There must be safeguards to prevent contamination of the foods from contact with the customers.

• Food temperatures should be monitored in multiple food items at varying food depths.

Holding food temperatures above 140° F for extended periods can have an undesirable effect on the quality of foods due to such things as loss of nutrients, flavor changes, and drying of the food. Cooked foods are usually cooled in order to be stored for longer periods at refrigerated temperatures. Refrigerated foods must be held at 41° F or below.

Improper cooling of potentially hazardous foods is consistently identified as a leading cause of confirmed foodborne illnesses in this country. Outbreaks occur because foods can contain spores or be re-contaminated with vegetative cells of pathogens during cooling. Re-contamination occurs through a variety of poor sanitation practices such as hand contact, contact with raw foods, unclean equipment, etc. If such contaminated foods are allowed to stay within the danger zone for extended periods, pathogens can grow to levels sufficient to cause food illness.

To assure that potentially hazardous foods are cooled safely through the danger zone, a two-part cooling standard has been developed. They must be cooled from 140° F to 70° F within two hours, and then from 70° F to 41° F within four hours.

Most pathogens' optimal growth temperatures fall between 140° F and 70° F, therefore it is crucial to move the temperatures of foods rapidly through this range. Once this temperature range has been passed, pathogen growth slows, and an additional 4 hours can be taken to finish cooling to 41° F. If a potentially hazardous food has been previously held at temperatures in the danger zone, the time they were held at those temperatures must be accounted for.

You should be aware that this two-part standard may not apply to all foods. The Food Code specifically addresses foods prepared from ingredients held at room temperature, for example, canned chicken. Since the starting temperature of the food is generally around 70° F, th