CONSIDERACIONES METODOLOGICAS

The terms cleaning and sanitizing (or sanitation) are sometimes erroneously assumed to be one and the same, when in fact there are important differences.

Cleaning is the physical removal of visible soil and food from a surface. Sanitizing is a procedure that reduces the number of potentially harmful microorganisms to safe levels on food contact surfaces such as china, tableware, equipment, and work surfaces. Sanitized surfaces are not necessarily sterile, which means to be free of microorganisms.

Cleaning and sanitizing are resource-intensive procedures in any foodservice operation. They require time, labor, chemicals, equipment, and energy. Careful design and monitoring of the cleaning and sanitizing procedures results in optimal protection of employees and customers. Mismanagement of these two functions can result in:

• Injury or illness to employees and customers

• Waste of chemicals

• Damage to equipment and facilities

Typically the foodservice manager works closely with a representative of a chem-ical company to select cleaning and sanitation compounds appropriate to the needs of the operation. It is essential that managers understand the principles of cleaning and sanitizing and the many factors that influence these procedures.

Principles of Cleaning

Cleaning is a two-step task that occurs when a cleaning compound (or agent) such as a detergent is put in contact with a soiled surface. Pressure is applied using a brush, cloth, scrub pad, or water spray for a long enough period of time to penetrate the soil so it can be easily removed during the second step of rinsing.

Many factors influence the effectiveness of this cleaning process. Table 4.1 is a summary of these factors. Each of these factors must be considered when making a cost-effective selection of detergents and other cleaning compounds such as solvents, acids, and abrasives.

Detergents. The selection of a compound to aid in cleaning the many types of soil and food residues is complex because so many compounds are available from which to choose. An understanding of the basic principles involved in cleaning will assist the foodservice manager in making this decision.

Food contact surface A surface of equipment or a utensil with which food normally comes into contact

Table 4.1 Factors that influence the cleaning process.

Factor Influence on Cleaning Process

1. Type of water Minerals in hard water can reduce the effectiveness of some detergents. Hard water can cause lime deposits or leave a scale, especially on equipment where hot water is used, such as in dish machines and steam tables.

2. Water temperature Generally, the higher the temperature of the water used for cleaning, the faster and more efficient the action of the detergent; however, ≤ 120°F is recommended (and in some cases mandated), as higher temperatures can result in burns.

3. Surface Different surfaces, especially metals, vary in the ease with which they can be cleaned.

4. Type of cleaning compound Soap can leave a greasy film. Abrasives such as scouring powders can scratch soft surfaces. Many cleaning agents are formulated for specific cleaning problems; lime removal products are an example.

5.Type of soil to be removed Soils tend to fall into one of three categories: protein (eggs), grease or oils (butter), or water soluble (sugar).

Stains tend to be acid or alkaline (tea, fruit juice).

Ease of cleaning depends on which category the soil is from and the condition of the soil (e.g., fresh, baked-on, dried, or ground-in).

Detergents are defined as cleaning agents, solvents, or any substance that will remove foreign or soiling material from surfaces. Specifically listed are soap, soap powders, cleansers, acids, volatile solvents, and abrasives. Water alone has some detergency value, but most often it serves as the carrier of the cleansing agent to the soiled surface. Its efficiency for removing soil is increased when combined with cer-tain chemical cleaning agents.

The three basic phases of detergency are penetration, suspension, and rinsing.

The following actions and agents are required for each phase:

1. Penetration: The cleaning agent must penetrate between the particles of soil and between the layers of soil and the surface to which it adheres. This action, known as wetting, reduces surface tension and makes penetration possible.

2. Suspension: An agent holds the loosened soil in the washing solution so it can be flushed away and not redeposited. Agents, which vary according to the type of soil, include the following: For sugars and salts, water is the agent because sugars and salts are water soluble and are easily converted into solutions. For fat particles, an emulsifying action is required to saponify the fat and carry it away.

Soap, highly alkaline salts, and nonionic synthetics may be used. For protein parti-cles, colloidal solutions must be formed by peptizing (known also as sequestering or deflocculating). This action prevents curd formation in hard water; otherwise, solvents or abrasives may be needed.

3. Rinsing agent: This agent flushes away soils and cleaners so they are not redeposited on the surfaces being washed. Clean, clear hot water is usually effec-tive alone. With some types of water, a drying agent may be needed to speed

Wetting

The action of a cleaning agent to penetrate between particles of soil and between the layers of soil and a surface to which the soil adheres. This action reduces surface tension and makes penetration possible

Suspension

The action of a cleaning agent required to hold the loosened soil in the wash-ing solution so it can be flushed away and not redeposited

Saponify

To turn fats into soap by reaction with an alkali Detergent

Cleaning agents, solvents, or any substances that will remove foreign or soiling material from a surface

Sequestering

The isolating of substances such as a chemical ion so it cannot react. In foodservice this is a desired characteris-tic of polyphosphate deter-gents to bind lime and magnesium of hard water. soils and cleaners so they are not redeposited on sur-faces being washed

drying by helping the rinse water drain off surfaces quickly. This eliminates alka-line and hard water spotting, films, and streaks on the tableware or other items being cleaned.

In foodservice, the cleaning function focuses mainly on food contact surfaces, including china, glass, and metal surfaces. Common soils to be removed are grease and carbohydrate and protein food particles that may adhere to dishes, glassware, silverware, cooking utensils, worktable tops, floors, or other surfaces.

Some types of food soils such as sugars, starches, and certain salts are water soluble. The addition of a wetting agent to hot water will readily remove most of these simple soils. The soils that are insoluble in water, such as animal and vegetable fats and proteins, organic fiber, and oils, are more difficult to remove.

Abrasives or solvents may be necessary in some cases to effect complete cleanliness.

The use of a “balanced” detergent or one with a carefully adjusted formula of ingredients suitable for the hardness of the water and the characteristics of the soil is advised in order to produce the best results. The properties of the detergent must cause complete removal of the soil without deposition of any substance or deleteri-ous effect on surfaces washed.

Detergents for dishwashing machines are complex combinations of chemicals that completely remove soil in a single pass through the machine. The selected detergent works to soften the water, solubilize and emulsify greases, break down proteins, suspend soils, protect the metal of the machine, increase wetting action, and counteract minerals in the wash water. Other characteristics desired in some situations are defoaming action where excess sudsing is a problem and chlorination action where a chlorine-type detergent is used to remove stains and discolorations.

Solvent Cleaners. Solvent cleaners, commonly referred to as degreasers, are nec-essary to clean equipment and surface areas that get soiled with grease. Ovens and grills are examples of areas that need frequent degreasing. These products are alka-line based and are formulated to dissolve grease.

Acid Cleaners. Tough cleaning problems such as lime buildup on dishwashing machines and rust on shelving are treated with acid cleaners. There are a number of these products from which to choose, and they vary depending on the specific pur-pose for the product.

Abrasives. Abrasive cleaners are generally used for particularly tough soils that do not respond to solvents or acids. These products must be used carefully to avoid damage to the surface that is being cleaned.

Principles of Sanitation

Immediately after cleaning, all food contact surfaces must be sanitized. Heat and chemical sanitizing are the two methods for sanitizing surfaces effectively.

Heat Sanitizing. The objective of heat sanitizing is to expose the clean surface to high heat for a long enough time to kill harmful organisms. Heat sanitizing can be done manually or by a high-temperature machine. The minimum temperature

Table 4.2 Minimum washing and sanitizing temperatures for heat sanitation.

Wash Sanitize

Manual 110°F 171°F

Machine (spray types)

1. Stationary rack, single temperature machine 165°F 165°F

2. Conveyor, dual temperature machine 160°F 180°F

3. Stationary rack, dual temperature machine 150°F 180°F 4. Multi-tank, conveyor, multi-temperature machine 150°F 180°F (1) Some local regulations may mandate stricter standards.

(2) Minimum time for exposure to heat is 1 minute.

(3) 194°F is the maximum upper limit for heat sanitation for manual or machine methods, as higher temperatures cause rapid evaporation and therefore inadequate time for effective sanitation.

Clean-in-place (CIP) A method of cleaning that requires no disassembly Clean-out-of-place (COP) A method of cleaning whereby equipment can be partially disassembled for cleaning

Source: From the 2005 Food Code, U.S. Public Health Service.

range necessary to kill most harmful microorganisms is 162°F to 165°F. Table 4.2 summarizes minimum washing and sanitizing temperatures for manual and machine methods.

Chemical Sanitizing. A second method for effective sanitizing is through the use of chemicals. One of the reasons for choosing this method over heat sanitizing is the savings that are realized in energy usage, as lower water temperatures are used with chemical sanitizers, eliminating the need for booster heaters.

Chemical sanitizing is achieved in two ways. The first is by immersing the clean object in a sanitizing solution of appropriate concentration and for a specific length of time, usually one minute. The second method is by rinsing, swabbing, or spray-ing the object with the sanitizspray-ing solution. The rinsspray-ing and sprayspray-ing methods can be done manually or by machine. Careful management of sanitizers is important for several reasons including:

• The sanitizer becomes depleted over time and must be tested frequently to ensure that the strength of the solution is maintained for effective sanitizing. Test kits are available from the manufacturer.

• The sanitation solution can get bound up by food particles and detergent residues if surfaces are inadequately rinsed, leaving the sanitizer ineffective.

The three types of commonly used chemical sanitizers in foodservice operations are chlorine, iodine, and quaternary ammonium compounds (quarts). The proper-ties of these sanitizers are summarized in Table 4.3.

Methods of Cleaning

Methods by which equipment can be cleaned are categorized into three groups.

Clean-in-place (CIP)or mechanical cleaning requires no disassembly or only partial disassembly. These pieces of equipment are cleaned and sanitized by the circulation of the chemical compounds through a piping system. This method of cleaning is most often applied to stationary or built-in equipment. Clean-out-of-place (COP)

Manual cleaning Complete disassembly of equipment for cleaning and functional inspection

Table 4.3 Properties of commonly used chemical sanitizers.

Chlorine Iodine Quaternary Ammonium

Minimum Concentration

•For immersion 50 parts per million (PPM)

12.5–25.0 ppm 220 ppm

•For spray cleaning 50 PPM 12.5–25.0 ppm 220 ppm

Temperature of Solution

Above 75°F (24°C) 75°F (29°C) Above 75°F (24°C)

Below 115°F (46°C) Iodine will leave solution at 120°F (49°C)

Contact Time

•For immersion 7 seconds 30 seconds 30 seconds—some

products require longer contact time—read label

•For spray cleaning Follow manufacturer’s directions

Must be below 8.0 Must be below 5.0 Most effective at 7.0, but varies with compound

Quickly inactivated Made less effective Not easily affected

Reaction to Hard Water Not affected Not affected Some compounds inactivated—read label;

hardness over 500 ppm is undesirable

Indication of Proper

Strength Test kit required Amber color indicates presence. Use test kit to determine concentration

Test kit required. Follow label instructions closely

means that the equipment is partially disassembled for cleaning. Some removable parts may be run through a dish machine. The third category is manual cleaning that requires the complete disassembly for cleaning and functional inspection.

D ^ISHWASHING

Dishwashing (sometimes referred to as warewashing) requires a two-part operation, that is, the cleaning procedure to free dishes and utensils of visible soil by scraping or a water flow method, and the sanitizing or bactericidal treatment to minimize micro-biological hazards. Dishwashing for public eating places is subject to rigid regulations.

Figure 4.1 Three-compartment stainless steel pot and pan sink.

Courtesy of Hobart Corporation, Troy, Ohio.

The two groups of equipment and utensils that are commonly considered for dis-cussion under dishwashing are kitchen utensils, such as pots, pans, strainers, skil-lets, and kettles soiled in the process of food preparation, and eating and drinking utensils, such as dishes, glassware, spoons, forks, and knives.

Kitchen Utensils

Mechanical pot and pan washing equipment is relatively expensive; therefore, in many foodservices this activity remains a manual operation. A three-compartment sink is recommended for any manual dishwashing setup (see Fig. 4.1).

Soil is loosened from the utensils by scraping and then soaking them in hot water in one compartment of the sink. After the surface soil has been removed from the utensils, the sink is drained and refilled with hot water to which a washing com-pound is added. This step can be eliminated with a four-compartment sink that has a presoak compartment. The utensils are washed in the hot detergent solution in the first compartment; rinsed in the second compartment, and sanitized in the third compartment.

There are several methods for sanitizing both dishes and utensils. One recom-mended method is by immersing them for at least one minute in a lukewarm (at least 75°F) chlorine bath containing a minimum of fifty parts per million (ppm) available chlorine. Dishes and utensils must be thoroughly clean for a chlorine rinse

to be an effective germicidal treatment. Another method of sanitizing hand-washed dishes or utensils is immersion in clean soft water of at least 170° for one minute.

The hot, clean utensils should be air dried before being stacked upside down on racks or hung for storage.

Dishes, Glassware, and Silverware

Items used for eating and drinking can be washed by hand or by mechanical dish-washers. Prewashing or preflushing, which applies to any type of water scraping of dishes before washing, is recommended to minimize food soil in the wash water. The usual types of water scraping equipment include (1) a combination forced water stream and food waste collection unit built into the scraping table, by use of which dishes are rinsed under the stream of water before racking, (2) a hose and nozzle arrangement over a sink for spraying the dishes after they are in racks, and (3) a prewash cabinet through which the racks of soiled dishes pass and are jet sprayed to remove food particles prior to their entering the wash sec-tion of the dishwashing machine. The prewash cabinet can be built in as part of the larger model machines or, in small installations, may be a separate unit attached to the wash machine in such a way that the water used is the overflow from the wash tank. The prewash water should be at a temperature of 110°F to 140°F to provide for the liquefying of fat and the noncoagulation of protein food particles adhering to dish surfaces. The installation and use of a prewash system lessens the amount of organic waste and the number of microorganisms entering the wash tank, removes fat that might otherwise result in suds formation, reduces the number of wash water changes, cuts the costs for detergents, and results in cleaner dishes. Figure 4.2 is an example of a job breakdown for the mechanical washing of tableware.

After the prerinse, the dishes are loaded into racks or on conveyor belts in such a way that food-contact surfaces will be exposed to direct application of the wash water with detergent and to the clean rinse waters. Figures 4.3 and 4.4 are two examples of dishwashing machines. Cups, bowls, and glasses must be inverted and

Figure 4.2 Job breakdown for washing tableware in a dish machine.

Tableware Cleaning and Sanitizing Procedure 1. Fill the soak tub with hot water.

2. Dispense soaking agent into the soak tub after water reaches proper depth as indicated by a line etched into the tub.

3. Place rack into the bottom of the soak tub.

4. Fill with soiled tableware to cover the bottom of the rack.

5. Send the rack through the dish machine.

6. Retrieve the rack and carry back to the loading end.

7. Place tableware in brown plastic cylinders with the food-contact end facing up (limit to 10 pieces per cylinder—do not overfill).

8. Place cylinders on the rack and run through the machine two more times.

9. Wash hands.

10. Shake excess water from cylinders and place on a clean cart; transport to the sorting area.

Figure 4.3 Double-tank, automated dish machine.

Courtesy of Hobart Corporation, Troy, Ohio.

overcrowding or nesting of pieces avoided if dishwashing is to be effective. Wash water shall not be less than 120°F, and if hot water is the sanitizing agent, the rinse water shall be 180°F. Figure 4.5 is an example of a dish machine temperature docu-mentation form for quality control. The pressure of the rinse water must be main-tained at a minimum of 15 pounds per square inch (psi) but not more than 25 psi to make the sanitizing effective.

China, glassware, and silver can be washed in a multipurpose machine, but it is preferred wherever possible to subject glasses to friction by brushes so that all parts of the glass are thoroughly cleaned, which means the use of a special machine designed for that purpose (Fig. 4.6). This is especially important in bars and similar establishments where glasses are the primary utensils used. To prevent water

Courtesy of Hobart Corporation, Troy, Ohio.

Figure 4.5 Temperature documentation form.

Month Breakfast Lunch Dinner

Wash Rinse Wash Rinse Wash Rinse

1 2 3 4 5 6 7 8 9 10 11

Heartland Country Village Dishwasher Temperatures

135

Figure 4.6 Glasswasher.

Courtesy of Hobart Corporation, Troy, Ohio.

spotting, it is advisable to use a suitable detergent for the washing of silver and also a drying agent with high wetting property in the final rinse water to facilitate air drying. The introduction of a drying agent with low foam characteristics into the sanitizing rinse promotes rapid drying of all types of tableware. Provision for the storage of clean glasses and cups in the racks or containers in which they have been washed reduces the possibility of hand contamination.

Some machines are designed for a chemical solution rinse rather than the high-energy use of the 180°F temperature water. In this case, the rinse water used with the chemical sanitizer shall not be less than 75°F or less than that specified by the manufacturer. Chemicals used for sanitizing should be dispensed automatically to make certain that the proper amount and concentration are used. Dishes can be

Some machines are designed for a chemical solution rinse rather than the high-energy use of the 180°F temperature water. In this case, the rinse water used with the chemical sanitizer shall not be less than 75°F or less than that specified by the manufacturer. Chemicals used for sanitizing should be dispensed automatically to make certain that the proper amount and concentration are used. Dishes can be