< The Flow of Food Geographic Information System Software

The Flow of Food


The flow of food is the path food takes to move through an operation from purchasing, receiving, storing, freezing, thawing, preparing, and cooking to holding, cooling, reheating and serving. Foodservice directors and managers are responsible for the safety of the food at every step in this flow. As mentioned before, there are five risk factors or foodhandler mistakes that can cause foodborne illness: not purchasing food from approved, reputable supplier, not cooking food in a correct temperature, not holding food in a correct temperature, not using clean and sanitized equipment and utensils and not practicing good personal hygiene. Assuming food is bought from a reputable and approved supplier and is safe, there are four main factors behind foodborne illnesses: time-temperature abuse, cross-contamination, poor personal hygiene and poor cleaning and sanitizing. Here time-temperature abuse, cross-contamination and thermometers will be explained.

Time-Temperature Abuse and Control

- TCS foods are foods that require time (T) and temperature (T) control (C) for safety (S)
- Examples of TCS foods are milk and dairy products, meat,poultry, fish, shellfish, baked potatoes.
- The temperature danger zone (TDZ) is between 41 F and 135 F and faster growth between 70 F and 125 F.
- The longer food stays in the TDZ, the more chance pathogens will grow to an unsafe level.
- We must reduce the time food spends in TDZ to keep food safe.
- If food stays in TDZ more than 4 hours, discard the food.

Food is temperature abused if:
- Stored at incorrect temperature.
- Cooked to the wrong internal temperature.
- Held at the wrong temperature.
- Cooled or reheated incorrectly.

How to Prevent Time-Temperature Abuse:
- Monitoring - Establish sound policies and procedures, train foodhandlers and monitor them.
- Tools - Provide foodhandler's right kind of thermometers and timers.
- Recording - Document when temperature is taken in a simple form.
- Time and Temperature Control - Establish procedures to limit time food spends in TDZ.
Corrective Action
- Make sure foodhandlers know what to do if time and temperature is abused.

Cross-Contamination and Control

- Cross-contamination occurs when pathogens are transferred from one surface or food to another.
- Pathogens can spread from food or unwashed hands to prep area, other food, equipment and utensils.
- They can move easily in the entire operation and contaminate everything in their path.
- Cross-contamination can occur at any point in the flow of food.
- Always keep raw food away from ready to eat food.
- Use separate equipment when handling different foods.
- Clean and sanitize all work surfaces, equipment, and utensils after each use.
- Prepare ready-to-eat food and raw meat, fish, poultry at different times if using the the same prep table.
- Do not add contaminated ingredients to food that receives no further cooking.
- Do not allow ready-to eat food to touch contaminated surfaces.
- Do not allow contaminated food to touch or drip fluids onto cooked or ready-to-eat food.
- Do not touch contaminated food and then touch ready-to-eat food.
- Do not allow contaminated cleaning cloths to touch food-contact surfaces.
- Buy foods that do not require a lot of prepping or handling.


- Bimetallic Stemmed Thermometer with calibration nut, easy-to-read markings and dimple
- Thermocouples and Thermistors Kinds:
- Immersion Probes
- Surface Probes
- Penetration Probes
- Air Probes
- Other Types of Thermometers:
- Infrared (Laser) Thermometers
- Maximum Registering Thermometers
- The Time and Temperature Indicator (TTI)

General Thermometer Guideline

- Always follow manufacturer's direction on how to use, care for and calibrate each type of thermometer.
- Wash, rinse and sanitize and air-dry thermometers and their storage cases.
- Use sanitizing solution that is for food-contact surfaces.
- Calibrate thermometers after they are bumped, dropped, or experienced severe temperature changes.
- Calibrate thermometers before each shift.
- Replace thermometers that can not be calibrated
- Use glass thermometers such as candy thermometers only when they are enclosed in a shatter proof casing.
- Insert the probe in the thickest part of the food when checking its temperature.