Here’s information intended to cover the basics in food safety. By the end of this reading you should learn enough to be fairly knowledgable in how to prepare food safely in your establishments.
Basic Food Safety and Hygiene
- Food Contamination 3 types of food contamination:
- Chemical –harmful chemicals getting into food through improper storage or excess concentration
- Physical –objects that make their way into food usually during preparation, i.e. hair, band aids, finger nails, metal savings, parts of equipment.
- Biological –small or microscopic organisms that are in the food or are introduced through improper handling. 5 categories of biological contaminates:
- Bacteria –single celled, can grow anywhere (do not need a living host, i.e. human or animal, to reproduce)
- Viruses –i.e. Hepatitis A, Norovirus. Must have a living host to reproduce. Some viruses can be spread even after symptoms stop so it is very important to always practice good personal hygiene like hand washing.
- Parasites –common in fish, pork, and wild game. Be sure to purchase food from approved sources, and to freeze or cook to appropriate temperatures
- Protozoan –i.e. Giardia, Cryptosporidium. Like a virus, must have a living host to reproduce.
- Fungus and Yeast –require an acidic environment with low water activity. Typically cause food spoilage and not illness
Bacteria and Viruses are the most common issues. They can’t be killed by freezing, cold holding or hot holding.
Bacteria need the following conditions to reproduce:
- Food –high protein, high carbohydrate source (i.e. meat, seafood, poultry, cooked plant food like pasta, rice, baked potatoes)
- Acidity –Bacteria typically needs low acidity food to reproduce
- Temperature – between 41 degrees F and 135 degrees F is the ‘Danger Zone’ when bacteria begin to rapidly reproduce
- Time –too long in the danger zone temperature range will lead bacteria to reproduce, the maximum amount of tiem some foods can spend in the danger zone is 4 hours.
- Oxygen –some bacteriz are aerobic, requiring oxygen, while others are anaerobic and do not require oxygen to reproduce
- Moisture –Bacteria require moist foods. Plain water has water activity of 1.0, bacteria require water activity of .85 or higher.
Use the acronym “FAT TOM” to easily remember these conditions. Foods that meet these criteria are known as “potentially hazardous foods” and have the potential to cause food borne illness.
- Holding Times and Temperatures
Top 5 causes of food borne illness:
- Improper holding time and temperatures
- Poor personal hygiene
- Inadequate cooking
- Contaminated equipment
- Food from an unsafe sources
Improper holding time and temperature refers to the principle of keeping hot foods hot and cold foods cold.
Harmful bacteria rapidly reproduce between 41̊F (5̊C) and 135̊F (57̊C) this is known as the temperature danger zone. The longer food spends in this temperature zone the more dangerous. Specifically, food should not be left in the temperature danger zone for longer than 4 hours. It is important to monitor time and temperature during the food preparation process.
When you are ready to cool food from hot to cold, use the following techniques to reduce the time the food spends in the temperature danger zone, before putting the food in the fridge:
- Ice bath
- Shallow pans, preferably metal
- Smaller portions
- Frequent stirring
Food should be cooled from 135̊F (57̊C) to 70̊F (21̊C) within 2 hours. Then food can be cooled from 70̊F (21̊C) to 41̊F (5̊C) or lower within the next 4 hours. Putting hot food straight into the fridge raises the temperature and can put other foods at risk of contamination. When food reaches 70 ̊F it can be cooled further in the fridge in a shallow, uncovered container. Only leave food uncovered when cooling and be sure to cover when the temperature has dropped to 41̊F.
Keep in mind that refrigeration only slows down, and does NOT prevent bacterial growth. To properly keep foods cool to help avoid food contamination you should also practice the following:
- Do not over fill the refrigerator
- Refrigerate food as soon as possible after buying, or receiving a shipment
- Do not thaw foods at room temperature: There are 3 acceptable ways to thaw food:
- Under cold running water
- In the refrigerator
- Or as part of the cooking process
- Personal Hygiene
Poor personal hygiene is the second most common cause of food borne illnesses. Common types of illness derived from poor personal hygiene include:
- Hepatitis A
- Salmonella Typhi
- Shiga-Toxin producing E. Coli
Practice Good Hygiene:
- Wash your hands
- Report illnesses
- Shower or bathe daily
- Wear clean appropriate clothing
- Proper Hand Washing:
- Apply soap
- Vigorously scrub hands and arms for at least 20 seconds
- Clean under finger nails and between fingers
- Rinse under running water
- Dry hands with single use paper towel or warm air hand dryer
- When should you be washing your hands in order to ensure safe food handling?
- After using the restroom
- After touching face or body
- After sneezing, coughing, or using a tissue
- After smoking, chewing tobacco, or chewing gum
- After taking out the garbage
- After handling dirty dishes
- After handling raw foods and before handling ready to eat foods
- Between glove use
When using gloves, remember they should never be used in place of hand washing and should be changed regularly. Be sure to change gloves when you change a food preparation task or if they become soiled or torn. When changing gloves, it is still important to wash your hands before putting fresh gloves on.
- Reporting Illnesses:
If an employee has the following symptoms they are restricted from working around food or utensils in a food establishment
- Sore throat with fever
If a food worker has any of these symptoms and works with high-risk populations they are excluding from coming to work at all.
If an employee is diagnosed with Hepatitis A, E. Coli, Shigella, or Salmonella they are excluded from coming to work and the proper regulatory authorities must be notified. Medical clearance is usually required before an employee is allowed to return to work.
- Inadequate Cooking and Contaminated Equipment
The third most common cause of food borne illnesses is improper cooking. Potentially hazardous foods must be cooked properly to ensure the destruction of harmful microorganisms.
Cooking temperatures are split into three categories:
- 145 ̊F (63̊C) –whole muscle, intact beef, pork, veal, lamb, eggs and fish must be cooked to a minimum of 145̊F
- 155̊F (68̊C) –ground beef, pork, veal, lamb, and injected meats must be cooked to a minimum of 155̊ F
- 165 ̊F (74̊ C)–all poultry, stuffed meats, and stuffing containing meat must be cooked to 165 ̊F
Reheating– when heating up foods that are already cooked, all foods must reach 165̊F or higher. Using a thermometer is the only way to ensure foods are reaching the correct temperatures.
Cross-contamination is the transfer of disease causing organisms from raw food to ready-to-eat food. This usually happens when a piece of equipment isn’t properly cleaned and sanitized.
Tips to prevent cross-contamination:
- Always wash your hands
- Always wash cutting boards, dishes, and utensils with hot soapy water. Do not just run your sanitizer clothe over a surface, wash it with soap first
- Use one cutting board for raw foods and one for ready to eat foods
- Never place cooked food on the same surface that held raw food
- Make sure raw foods in the refrigerator are sealed to prevent leakage
- Ready to eat foods should be stored above raw meat, eggs, fish, and poultry in teh refrigerator (store foods according to their cooking temperatures, 145̊ above 155̊ and 165̊ at the bottom)
- Sauce used for marinating should be discarded unless it is boiled before applying to cooked meats and fish
- Sanitizers are NOT cleaners: They do a poor job of lifting debris and grime from a surface. However, they do reduce the number of microorganisms on a surface to safe levels.
- Two effective methods of sanitizing a food contact surface:
- Chlorine or Bleach: 10 seconds to sanitize, cheap, but can be corrosive. Use proper concentration, 50-100 parts per million (ppm)
- Quaternary Ammonia: 30 seconds to sanitize, more exspensive, less corrosive. Proper concentration is 200-400 ppm
- Iodine: not commonly used in food establishments
- Heat: heat sanitation is only found in dish machines as the water must be at or above 160̊F (71 ̊C) at the plate’s surface.
Pots and pans that do not fit in a dish machine must be properly washed by hand:
- Scrape and rinse large debris
- Wash in warm soapy water at approximately 100̊F (38̊C)
- Rinse in clean warm water at about 100̊ F
- Sanitize and air dry
When to clean and sanitize:
- Surface is soiled
- Switching between raw and ready to eat foods
- Between food preparation tasks
Also remember that storage areas are for clean and sanitized equipment only. For example do not cut foods and place the knife back into a temporary storage container without properly cleaning and sanitizing it. Furthermore, be sure to maintain your equipment as microorganisms can more easily latch onto a well worn cutting board or pan.
- Adulterated Food
It is important to make sure your food comes from a credible and regulated source.
Here are some examples of foods that should be rejected and not be served to the public:
- Canned food with dents or creases
- Canned food that can’t be opened by a standard can opener
- Canned food that does not sit upright or is bulging
- Canned food with a cut on the end seam of the can
When buying or receiving a shipment of food one should pay attention to hot and cold holding temperatures, expiration dates, as well as possible spoilage or infestations.
Storage areas should be kept cool and dry with all food stored 6 inches off the floor and away from the walls. Use foods with the most recent expiration date last and be sure to date mark foods that are opened or have been prepared on site.
Potential hazardous foods cannot be stored for more than 7 days.
Disease vectors: insects or rodents that transmit disease-causing organisms to the skin, food, or other objects, i.e. cockroaches, rats…
Control these pests by cleaning and sanitizing regularly to deny them food and deny them access by leaving doors closed. To further prevent pests, be sure to properly store chemicals away from food and label everything. Furthermore, when using chemicals you should follow the label recommendations for proper use. Structurally, restaurants should be built with easy to clean, non porous surfaces with adequate lighting throughout the food preparation and storage areas to avoid disease vectors.
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