FOOD SAFETY: PREVENTING FOODBORNE DISEASE THROUGH PROPER COOKING, COOLING AND STORAGE RELATED TO DELTATRAK PRODUCTS 
Foodborne disease from biological contamination can happen at any time during the food preparation process. The processes of cooking, cooling and storage are particularly susceptible to contamination as preparers are required to prepare, move and store food. This paper will look at the food cooking, cooling and storing stages within a restaurant environment and address how some specific bacteria, viruses, and parasites can thrive and exist at each stage. It will also detail important steps and tools available to eliminate this threat.
Common Problems
Biological contaminations that can lead to disease are caused primarily by bacteria, viruses & parasites. During the cooking, cooling or storing stages biological contamination can be prevented by ensuring proper time and temperatures are used to prepare the foods and adhering to proper hygiene, cleaning and sanitization procedures. Additionally, reducing or eliminating cross contamination will also prevent contamination. Different bacteria have different temperatures that they need to thrive. These temperatures can range from as low as freezing to as high as 200 (93.3 C) degrees Fahrenheit. Most bacteria however thrive in the temperatures close to a human body's temperature of 98.6 (37 C) degrees Fahrenheit. The food industry often refers to the temperature range between 41 (5 C) and 135 (57 C) degrees Fahrenheit as the food temperature danger zone or that range of temperature when most foodborne microorganisms will rapidly grow. As food moves through the cooking, cooling and storage stages it must pass through this zone as quickly and safely as possible. Time, temperature, cleanliness and cross contamination are all key to keeping food safe during these stages.
Associated Costs
Costs associated with preventing foodborne contamination at a restaurant include providing employees with the proper training, equipment and tools they need to avoid contamination. Businesses that fail to prevent foodborne disease run the risk of losing the trust of its customers, jeopardizing its business and preventing it from remaining competitive. If food is not cooked, cooled and stored properly foodborne disease is not prevented which may lead to loss of reputation or customers. It could additionally lead to lower profits, fines, lawsuits, and even closure of the business. One example of one outbreak severely affecting a restaurant due to food contamination happened in 2003 in Pittsburgh, Pennsylvania. A Chi-Chi restaurant customer contracted hepatitis and as a result had to have a liver transplant. The illness was traced back to the restaurant and the customer received a settlement of $6.25 million. Failure to meet food safety regulations, legislation and inspections could cause the establishment to incur additional costs to correct citations. From a fiscal standpoint foodborne disease costs in the United States are $152 billion per year according to a report from the Pew Charitable Trust. The World Health Organization reports that in industrialized countries, the percentage of the population suffering from foodborne diseases each year has been reported to be up to 30%. Clearly preventing foodborne disease should be an establishment's highest priority from both a monetary and moral viewpoint.
Cooking Stage
Bacteria can survive as a result of inadequate cooking. They can also multiply with prolonged cooking at low temperatures and bacterial spores can even survive boiling. Examples of some virulent bacteria that can be a problem in the cooking stage are Staphylococcus Aureus, Salmonella and Bacillus Cereus. All can cause nausea, vomiting and cramping and can be avoided by cooking food according to proper times and temperatures, preventing cross contamination and using proper hand washing techniques. Symptoms from illnesses caused by these bacteria starts anywhere from 30 minutes and lasting a day as in the case with Bacillus Cereus to starting as late as 48 hours after contact and lasting 3 days as in the case of the Staphylococcus Aureus bacteria. E. coli 0157:H7 is another trouble causing bacteria that can cause diarrhea and kidney failure and can be prevented with the use of proper sanitization methods. E. coli symptoms can show up as late as 72 hours and last for up to 3 days. Viruses, such as Hepatitis A and Norovirus, cause fever, nausea, vomiting and cramping and can be transmitted during the cooking process by cross contamination and poor hygiene. Norovirus symptoms appear in approximately 48 hours and can last 2 days. Hepatitis A symptoms do not appear until 15 to 50 days after contact and can last anywhere from several weeks to several months. This long period before symptom onset makes tracing contamination difficult. Parasites such as Anisakis spp. and Cyclospora cayentanensis can be transmitted to customers through poor hygiene and uncooked or under cooked foods and also cause vomiting and diarrhea respectively.
Time & Temperature
An often deadly misconception is that food is done and safe to eat when it turns brown. In fact according to the USDA one out of every four hamburgers turns brown before its internal temperature has reached its safe temperature. Different foods require different minimum internal temperatures to be determined safe but typically they range from 140 (60 C) to 165 (73.9 C) degrees Fahrenheit. In addition to reaching this temperature the product must be held at that temperature for a set period of time. As an example the USDA lists eggs as requiring an internal temperature of 145 (62.8 C) degrees Fahrenheit maintained for 15 seconds whereas a thicker pork roast they state requires a temperature of 145 (62.8) degrees Fahrenheit maintained for 3 minutes.
Consumers doubting the need for using temperature as a gauge should consider one CDC report that stated in 2007 one foodborne outbreak resulted in seven food poisoning victims in Long Island, New York and county health officials believed that all contracted the E.coli bacteria from under cooking hamburger meat. One of the victim's kidneys shut down as a result of the infection. Another report stated that in 1993 there were over 500 confirmed illnesses with four deaths from an E.coli outbreak associated from eating undercooked hamburgers from just one restaurant chain. The only safe method to determine if a food is cooked is to take its internal temperature with an accurate thermometer. Accurate probe and bi-metal thermometers are effective tools to prevent undercooking.
Hygiene, Cleanliness & Sanitization
Poor hygiene has also been linked to outbreaks of foodborne disease. One case reported by the Center for Science in the Public Interest or CSPI reported that one Salmonella outbreak at one quick service restaurant sickened thirty-eight people and may have killed one. The cause was determined to be linked to employees not washing their hands before handling food. According to the CDC and industry experts 70 to 80 percent of foodborne illnesses are caused by improper hand washing. Many people have the misconception that washing their hands a couple times per day is sufficient in preventing transmission of bacteria when in fact hand washing should take place anytime before, between and after touching raw food and after touching any part of a person's body or cleaning. Equipment and utensils must likewise be cleaned and sanitized. Further support for the value of personal and equipment cleanliness comes from the FDA that reports that a virus, such as the human influenza virus, can survive on surfaces for up to eight hours. Management must ensure that employees are familiar with the proper methods of cleaning and sanitizing equipment and utensils. The basic process steps involved in cleaning and sanitization are:
1. Pre-cleaning – Remove, scrape and rinse to remove loose food or dirt
2. Wash - Use detergent solutions to remove stuck-on food or dirt
3. Rinse to remove food/dirt and detergent
4. Sanitize to kill attached surviving bacteria and viruses
5. Air Dry
Sanitization is accomplished by using either a thermal or chemical approach. The thermal approach uses very hot water or steam at a specific temperature and specific contact time. The thermal or heat sanitizing method for food utensils and equipment can be used in both a manual or mechanical warewashing set-up. The FDA Food Code states manually sanitizing equipment requires that the hot water must be 171 degrees Fahrenheit or above and the equipment must be immersed for at least 30 seconds. Additionally, when using the heat method in mechanical warewashing equipment the sanitizing rinse must fall between 180 & 194 degrees Fahrenheit. Thermometers or thermolabels should be on hand to routinely check the temperatures.
Using chemicals to sanitize equipment can be accomplished by submerging the equipment in or brushing or spraying an appropriate sanitizing solution on the items. The solution must be an approved solution and the equipment must be exposed to the solution at a set temperature for a set time. These vary depending on the type of solution used. The most common sanitizing chemicals used in the food service industry are Chlorine, Iodine and Quaternary Ammonium Compounds. Typically chlorine sanitization requires exposure for seven? seconds at a temperature of 100 degrees Fahrenheit. There are some variations depending on pH factors. Solutions that contain Iodine are called iodophors. Equipment sanitation with this solution requires exposure for 30 seconds at a temperature between 75 and 120 degrees Fahrenheit. Quaternary Ammonium Compound is another chemical solution used in the food industry. This chemical requires equipment to be exposed for 30 seconds at a temperature above 75 degrees Fahrenheit. Establishments need to check the chemical's labels for the appropriate time and temperature for the particular chemical in question. Chemical testing papers are available to test the concentration of chemicals being used.
Cross contamination
According to the Food Poison Journal in 2000 there were 64 confirmed cases of people having eaten at two Wisconsin Sizzler (customer?) restaurants testing positive for the E. coli bacteria. The Wisconsin State Department of Health concluded that the source of the outbreak was watermelon cross contaminated with raw meat. Many have the misconception that cross contamination only occurs when a contaminated food touches another food. In fact there are multiple ways bacteria or viruses can contaminate food. One devastating example occurred when Salmonella affected 850 people in 1995 in Florida. It was the largest outbreak of foodborne illness in Florida history. According to the Center for Science in Public Interest or CSPI officials believed that the bacteria was the result of workers using the same cutting board for raw meat and vegetables at the Margarita y Amigas restaurant in West Palm Beach. Using separate equipment such as cutting boards, knives and spoons for different foods is advised and using proper attire such as gloves, hats or hair nets can minimize cross contamination during all the cooking, cooling and storing stages.
Cooling Stage
Bacteria commonly found in the cooling stage of food preparation include Bacillus cereus and Clostridium perfringens. Bacillus cereus causes diarrhea and vomiting and is most commonly attributed to improper storage and cooling. Clostridium perfringens causes severe diarrhea and cramping and is preventable with properly cooled and reheated foods. Foodborne illness caused by improper cooling can be lethal as evidenced from one CSPI report that documented an incident in Georgia in 1993 that killed one and sickened seven customers of a delicatessen. The CDC officials traced the illness to botulism in cheese sauce left unrefrigerated for eight days. Cooling and storing the sauce properly as a leftover would most likely have avoided the episode. Bacteria not destroyed during cooking can multiply if food is not cooled properly before refrigeration. Food must pass through the food temperature danger zone quickly so that bacteria cannot start to multiply.
According to the CDC improper cooling of foods is the number one contributor to food contamination. Part of the reason for this high number is the misconception by many that simply placing the leftover food back into refrigeration is enough to cool the food safely. In fact there are very specific guidelines that must be followed in order to cool foods safely. There are available tools such as hot and cold time and temperature monitoring devices that can easily monitor foods using these specific guidelines.
Time & Temperature
The FDA's Food Code recommends that food be cooled from 140 (60 C) to 70 (21.1 C) degrees Fahrenheit within two hours and then from 70 (21.1 C) to 41 (5 C) degrees Fahrenheit within an additional four hours. This process requires handlers to either monitor the process manually with probe, bi metal or infrared thermometers or use automated heat/cool monitoring thermometers. These specialized automated thermometers can issue an alarm if the food does cool down properly or display a visual pass indicator notification if the food does cool safely. Once food has reached 70 degrees Fahrenheit it can then be transferred to a refrigerator for the additional cooling. To speed up cooling there are several other food handling methods available. Transferring food to shallow pans will help disperse the heat as will using a cooling paddle to stir the hot food. Using stainless steel as containers and placing containers in an ice bath are also effective methods of cooling food. Food handlers must verify that the foods are cooled properly prior to moving them back into storage. Temperatures can be monitored using a variety of thermometers including probe thermometers or specially designed automated cool down thermometers that track temperatures and time.
Hygiene, Sanitization and Cross Contamination
Hygiene and cross contamination are equally critical during the cooling stage as in the cooking stage. Cooling food properly and storing correctly is paramount. Foods should be covered prior to placing back into the refrigerator or storage to avoid contaminating other foods and should be kept separate from raw food. Work surfaces should be cleaned frequently.
Storage
Bacteria & viruses can thrive in dry storage and survive in refrigerated storage. Bacteria can multiply in refrigerated storage if the temperatures are too high or if foods are allowed to spoil. Many have the misconception that freezing kills bacteria. In fact freezing simply keeps bacteria from multiplying. Once food is thawed the bacteria is able to grow once more. In dry storage bacteria can multiply if food becomes damp. Viruses such as Hepatitis A can be spread from infected people to produce, salads and ready-to-eat foods. Other storage related contamination problems include pests. Pests can carry bacteria and viruses such as Salmonella, the Poliomyelitis virus and the Hantavirus. As described previously Hepatitis A symptoms include nausea, vomiting, diarrhea and fever while Salmonella symptoms include fever, diarrhea and cramps. Hantavirus victims may feel fatigued, run a fever and experience muscle cramps. The Poliomyelitis virus causes headache, fever and vomiting.
Time & Temperature
Refrigerated foods are stored in a variety of different refrigeration storage areas. These can be as simple as a standalone reach-in refrigerator or a larger walk-in or walk-through refrigeration room. Different foods require storage at different temperatures. For example, NEHA recommends storing fresh meat between 32 (0 C) and 41 (5 C) degrees Fahrenheit at a humidity level between 85 and 90 percent and fresh poultry between 30 (-1.1 C) and 36 (2 C) degrees Fahrenheit at a humidity level between 75 and 86 percent. The refrigeration unit's environment should be checked for the proper temperature whenever it is used. This can be achieved by manually checking the unit's internal thermometer or automatically accomplished with wide area temperature monitoring and alarm systems. The actual food temperatures should be checked at the beginning of the day and the end of the day and whenever there is a temperature fluctuation within the refrigeration unit. This can be accomplished by performing spot checks using either probe or infrared thermometers. Monitoring both ambient and food temperatures is necessary from a safety perspective and keeping accurate records of these temperatures is vital for restaurants to comply with federal, state and local regulations as well as documenting compliance for their own safety procedures.
Freezers keep frozen food at 0 (-17.7 C) degrees Fahrenheit or below. At this temperature foods can have a much longer shelf life. Fresh meat for example stored at 0 (-17.7 C) degrees Fahrenheit can last several months. The freezer temperature should be checked daily and should be defrosted regularly if it is not a frost free unit. Temperature controls and equipment such as wireless temperature monitoring systems or data loggers should be used to verify consistent temperature ranges.
Dry storage is used for items not requiring refrigeration such as foods packaged in cans, bottles and bags. NEHA recommends that the dry storage area should ideally be maintained at a temperature between 50 (10 C) and 70 (21 C) degrees Fahrenheit at a humidity level of 50 to 60 percent. This will ensure that the food shelf life is maximized. Thermometers, temperature control systems or wireless temperature monitoring systems are used for maintaining and recording consistent temperatures. These tools should be monitored on a regular basis.
Hygiene, Sanitization and Cross Contamination
Hygiene, sanitization and cross contamination can affect food in storage in much the same ways as in the previous stages. Food in storage is still susceptible to bacteria and viruses being transmitted due to poor hygiene or cross contamination. Employees should be trained on the necessity of hand washing and over all hygiene. Proper hand washing methods include washing hands with hot (around 100 (38 C) degrees Fahrenheit) water and soap, rubbing hands vigorously for at least 20 seconds, rinsing and drying hands with a single use paper towel or air dryer. Storage areas should be routinely cleaned and sanitized and pest control measures should be in place to minimize infestation possibilities. Food should be stored covered, off the floor and in open shelving. Raw foods should be stored away from ready to eat foods and should be stored below cooked foods to prevent cross contamination. Restaurants are also advised to use a first in first out or FIFO inventory system to minimize the chance of foods spoiling and becoming contaminated. Tools are available to ensure proper hygiene is being practiced and areas are kept clean to avoid cross contamination. These include chemical concentration test papers and strips, alcohol wipes and thermolabels.
Summary of Tools
Food service employees mush know the internal temperature of various foods during multiple stages of preparation in order to prevent foodborne diseases. Temperature instruments are vital for holding, thawing, cooking, cooling and storing various types of foods. Sanitization products are key to maintaining good hygiene and reducing cross contamination. Following is a summary of tools available to be used during cooking, cooling and storage of foods.
Temperature Tools
Relying on texture and color are not sufficient methods of determining if food has reached the recommended internal temperature and is safe to eat. Temperature monitoring tools are recommended to ensure foods either avoid or pass through quickly the food temperature danger zone between 41 (5 C) and 135 (57 C) degrees Fahrenheit. Temperature monitoring tools for cooking, cooling and storing foods are listed below.
- Monitoring tools to test cooking surfaces are available such as DeltaTRAK's Digital Thermocouple Thermometer which features specialized probes for checking surfaces, air/gas as well as standard penetration probes for checking foods as they cook or cool.
- During cooking, cooling or even storage FlashCheck digital probe thermometers are used to check raw food, food in the process of cooking, cooked or cooling foods. They are ideal for checking food at any stage of food processing. FlashCheck thermometers use a stainless steel reduced tip that allows for a faster recording time and the ability to more easily check thin mass foods such as a fillet of fish. FlashCheck thermometers' automatic calibration technology allows the user to calibrate the thermometers in the field in order to be sure the readings are accurate.
- Bimetal thermometers are cost effective thermometers used to monitor foods during cooking and cooling. Often referred to as pocket dial thermometers they can be used for example during cooking to monitor hot liquids to verify proper internal temperatures or during cooling to monitor cool down.
- FlashCheck Lollipop Min/Max probe thermometers are used to check foods by probing or leaving in storage areas to record minimum and maximum temperatures. These waterproof thermometers can also be used in dishwashers to verify and quantify the temperature of the final rinse temperature in commercial warewashers and dishwashers.
- DeltaTRAK's Min/Max Digital Alarm Thermometers with the capability to record minimum and maximum temperatures are very useful in monitoring salad bars, display cases, water tanks and storage areas where the probe is placed inside an area while the display remains outside for full visibility. They can also be set to emit an alarm if the temperatures fall out of the set parameters.
- DeltaTRAK's Heat/Cool Thermometeris the first thermometer to easily track the cooling rate of foods and issuing an alarm if foods do not cool safely. . These thermometers are ideal for ensuring that foods cool down from 135 to 70 (57 to 21 C) degrees Fahrenheit within 2 hours and then from 70 to 41 (21 to 5 C) degrees Fahrenheit within another 4 hours.
- Non contact Infrared thermometers such as the ThermoTrace thermometers quickly and accurately record temperatures from a distance or in hard to reach areas such as refrigerated cases or other cold storage areas.
- Wireless facility monitoring, recording and alarm systems such as DeltaTRAK's FlashLink Wireless environmental system can track temperature and humidity around the clock. The automated wireless system can be programmed to notify personnel if the storage environment temperature falls out of the acceptable temperature range. The Flashlink Wireless System's alarm technology reduces the chance of accidental temperature malfunctions that could result in loss of valuable product.
Hygiene and Sanitization Tools
Tools to aid in proper hygiene and minimizing cross contamination allow food handlers to deliver foods free of microorganisms harmful to consumers. Sanitization tools that help minimize cross contamination and promote proper hygiene are listed below and include wipes, testing strips, temperature labels and dishwasher thermometers.
- FlashCheck Lollipop Min/Max waterproof probe thermometers can also be used to verify and quantify the temperature of the final rinse temperature in commercial warewashers and dishwashers.
- DeltaTRAK Chlorine Test papers are used to ensure that the appropriate level of chlorine is being used in low temperature dishwashers to sanitize cookware and utensils. These chlorine test papers are used by dipping the paper into the water/chlorine solution and comparing the color results against a level chart.
- DeltaTRAK Quat Ammonium Test Papers are used in sinks and dishwashers to test quaternary ammonium solutions to confirm correct concentration of the chemical in the sanitization of cooking utensils and cookware. These test strips work in the same manner as the chlorine papers to confirm the chemical's appropriate concentration level.
- DeltaTRAK TempDot High Temp Thermolabels are self adhesive labels that can be adhered to plates. The plates with labels are run through a high temperature dishwasher where the label will change color when/if the temperature of the plate reaches the FDA Food Code (2009) specification of 160 degrees Fahrenheit needed to sanitize the items during final rinse. Tempdots confirm that the item itself within the dishwasher has reached the proper temperature for sanitization.
- Alcohol wipes are available for use in sanitizing thermometers. As thermometers are used in the cooking, testing and monitoring of food they must be sanitized between each use so as to avoid cross contamination.
Conclusion
Bacterial contamination can happen any time food is being handled including during the cooking, cooling and storing stages. Contamination can be effectively reduced or eliminated with knowledge of and attention to the three main influencing factors of time and temperature, hygiene and cross contamination. The proper use of sanitizing tools and temperature monitoring tools coupled with employees knowledgeable of proper hygiene practices can ensure a restaurant avoids the devastating consequences of foodborne disease outbreaks.
References
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National Environmental Health Association. (2010). Certified Professional Food Manager, Food Safety Training. Canada: Author
Schmidt R.H.. (1997). Basic Elements of Equipment Cleaning and Sanitizing in Food Processing and Handling Operations. Florida: University of Florida
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