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Chapter 2: Food Safety Hazards
Food can become harmful from the three types of contamination:
Physical, Chemical and Biological
What are Physical Hazards?
Physical hazards are physical objects that get into the food. Examples: Metal shavings, string, staples, hair, finger nails and broken glass (This is why protective shields must be placed on light fixtures in food preparation areas and items made of glass i.e. drinking glass should never be used as ice scoops.)
What are some physical hazards that you have actually experienced? **Closely inspect all food deliveries.
What are Chemical Hazards?
Chemical hazards occur when some sort of chemical gets into the food you are preparing. Examples: pesticides, cleaning chemicals and toxic metals.
What are Biological Hazards? Biological hazards are our biggest concern.
Definition of Biological Hazard: Disease-causing microorganisms and other living organisms that may be present in food.
Types of biological hazards:
Examples: sneezing or coughing on food, touching food with unwashed hands, or raw meat dripping onto cooked meat. Bacteria Bacteria are like people. They need almost all of the same things that people need in order to grow. Foodborne bacteria grow quickly in food if they get the right conditions.
To live and grow bacteria need: Grow best in foods that are: • F-ood (high in protein) Contains protein • A-cidity Level (neutral/slightly acidic) Slightly acidic • T-emperature (not too hot, not too cold) Warm • T-ime to grow (4 hours) Contains moisture • O-xygen (some do, some don't... not like people) • M-oisture (the wetter the better)
FAT-TOM is the key to controlling the growth of bacteria!
Food: What are Potentially Hazardous Foods? (PHF) Definition of PHF: Foods that are capable of supporting the rapid growth of microorganisms are potentially hazardous foods. These foods are often warm, high in protein, and slightly acidic.
Such food requires time-temperature control to prevent the growth of microorganisms and the production of toxins.
There are four major categories: 1. Food of animal origin that is raw, like raw meat. 2. Food of animal origin that is heat-treated, like cooked meat. 3. Food of plant origin that is heat-treated, like cooked beans, rice, spinach, corn & zucchini. 4. Food of plant origin that is raw, like raw seed sprouts and cut melons.
Foods (potentially hazardous foods) that need to be handled more carefully include:
• Beef • Poultry • Pork • Lamb • Fish & shellfish • Milk or milk products• Eggs • Garlic and oil mixtures • Soy-protein foods, tofu • Sprouts: Alfalfa sprouts, seed sprouts, etc. • Sliced Melons: watermelon cantaloupe • Cooked rice, beans, potatoes and other cooked plant food
NOT PHF: Whole, washed strawberries, whole cantaloupes, and whole melons are NOT PHF.
Key Point: Most potentially hazardous foods need to be kept cold or frozen until they are prepared and cooked. This will help keep the food safe.
GROWTH NEEDS OF BACTERIA Moisture (Aw = water activity ) as a Growth Need of Bacteria Do we have much control of moisture?
Controlling the growth of microorganisms: So, you can change some PHF to non-PHF by removing the moisture, like raw bacon to crisp bacon. Or by adding sugar, salt, alcohol, or acid to a food to lower its water activity. Acidity (pH) as a Growth Need of Bacteria Do we have much control of this growth need? pH is a measurement of how acidic or alkaline a food is. Very few microorganisms grow in foods that are highly acidic or highly alkaline. Microorganisms which cause foodborne illness grow well in foods which are low in acid, foods which have a pH between 4.6 and 7.5. • The pH scale ranges from 0 to 14. • A food with a pH between 0 and 7 is acidic. • A food with a pH between 7 and 14 is Alkaline. • Distilled water is neutral and has a pH of 7. Foodborne microorganisms typically do not grow in alkaline foods, such as crackers, or highly acidic foods, such as lemons. Of course there are a few exceptions, for example, E. coli O157:H7 has been found in unpasteurized apple juice with a pH below 4.
This is why commercial mayonnaise does NOT have to be refrigerated when it is delivered to a food establishment.
Oxygen as a Growth Need of Bacteria Not all bacteria require oxygen to survive and grow. Bacteria are divided into three groups to distinguish their oxygen requirements. 1.
Aerobic bacteria need oxygen to grow. Temperature vs. Bacterial Growth * * * 41º to 135ºF * * * Do we have much control of this growth need?
Key Point: Harmful bacteria multiply rapidly when the temperature is between 41º and 135ºF.Temperatures between 41º and 135ºF are referred to as the “Temperature Danger Zone” because of the rapid growth of bacteria that occurs in this range.
1. To prevent bacteria from growing to unsafe levels, keep foods at 41ºF or below or 135ºF or above.
2. Do not expose food to the Temperature Danger Zone for more than a total of four hours. (Exception – under 1998 Texas Food Establishment Rules you have up to 6 hours for pre-cooling.)
3. The more accumulated time that food (PHF) spends in the Temperature Danger Zone (TDZ) from receipt to service, the greater the possibility of bacterial growth and foodborne illness.
Remember: Keep food out of the temperature danger zone. Keep hot foods hot, cold foods cold. Key Point: To prevent bacteria from growing, the goals are to cut down handling time, keep food at proper temperatures and limit the risk of contamination from your hands or other surfaces like cutting boards that haven’t been cleaned or sanitized.
Time/Temperature Control for Safety (TCS) Question: Would you rather have $100,000 right now, or a penny today, 2 cents tomorrow, 4 cents the next day, 8 cents the next... doubling each day for a month?
• Potentially Hazardous Food (PHF) held between 41°F and 135°F for 4 hours or more can cause foodborne illness if consumed. • How do microorganisms grow? Microorganisms grow by splitting in half. One microorganism becomes 2. 2 become 4 4 become 8... and they keep doubling.
Amount of money received each day:
Even though you only received $163.84 half way through the month... notice that you received over a million dollars on the 28th day and over 5 million the 30th day. This growth rate is also true about bacteria. After 2 hours in temperature danger zone there may not be many bacteria present... but when PHF is near 4 hours in the temperature danger zone, millions of new microorganisms are reproducing each minute.
When PHF has been in the Temperature Danger Zone for 4 hours, it must be discarded. That statement seems very easy to understand, but when it happens some people don't recognize it or don't want to admit it. For instance, here is something that happens every day. An employee cooks beans or rice and puts them in the walk-in cooler to cool. Six hours later someone checks them and finds they are still at 65º F. It's time to use them for lunch. The lunch crowd will be showing up in about 15 minutes. What does the person do? Heat them up and use them for lunch? Or throw them away and have no beans or rice for lunch and risk getting fired? The beans and rice must be discarded!
Time-only as a public health control. How can we use time-only as a public health control? What if we don’t want to take the temperature of certain PHF? How can we do that? We can use time-only as a public health control if we have written procedures explaining how we will control the food so it will not be in the temperature danger zone for more than 4 hours.
Examples of foods that may use time-only are Hollandaise sauce for Eggs Benedict, breakfast tacos at a convenience store, pigs in a blanket at a bakery.
Characteristics of bacteria that cause foodborne illness 1. Some transform into spores, a change that protects the bacteria from unfavorable conditions. Spores are another reason that food handlers should always cook, cool and reheat foods properly. 2. They are living, single-celled organisms. 3. They may be carried by a variety of means: food, water, humans, and insects. 4. Under favorable conditions, they can reproduce very rapidly. 5. Some can survive freezing.
Viruses
Viruses are the smallest of the microbial contaminants. While a virus cannot reproduce in food, once inside a human cell, it will produce more viruses.
Characteristics of Viruses:
The most effective ways to reduce the risk of viruses: 1. Practicing good personal hygiene is an important way to prevent the contamination of food by foodborne viruses. Wash hands thoroughly and frequently especially after using the restroom. 2. Minimize bare-hand contact with ready-to-eat food.
Hepatitis A is primarily found in the feces of people infected with the virus. Hepatitis A is often transferred to food when infected foodhandlers touch food or equipment with fingers containing feces. An infected person may not show symptoms for weeks, but can be very infectious.
Food Commonly Associated with the Virus Ready-to-eat food, including: Deli meats, produce, salads. Raw and partially cooked shellfish
Prevention Measures
jaundice or have been diagnosed with hepatitis A.
Hazards are real ! October - November, 2003 In the largest foodborne illness outbreak in the history of the U.S., 3 people died and over 500 people linked to the Chi-Chi's Mexican Restaurant in the Beaver Valley Mall are confirmed to have the virus. At least 14,500 people could have been exposed.
NOTE: Hepatitis A is not the same disease as Hepatitis B which is blood-borne Hepatitis. Employees with blood-borne Hepatitis need not be excluded or restricted. A person contracts hepatitis B when blood from an infected person enters the body of a person who is not infected.
Norovirus is also primarily found in the feces of people infected with the virus. It has also been found in contaminated water. People become contagious within a few hours of eating contaminated food. Proper handwashing is essential to prevent the illness. It is also ritical to prevent foodhandlers from working with food if they have symptoms related to the illness.
Food Commonly Associated with the Virus Ready-to-eat food, shellfish contaminated by sewage
Prevention Measures 1. Wash hands properly. 2. Exclude employees who have been diagnosed with Norovirus from the establishment. 3. Exclude foodhandlers with diarrhea and vomiting from the establishment. 4. Also purchase shellfish from approved, reputable suppliers.
Another biological hazard is Fungi They are found naturally in air, soil, plants, water and some food. Mold, yeast and mushrooms are examples of fungi. Fungi most often cause food to spoil.
Molds are fungi that look like fuzzy growths or powder when growing on food. 1. They spoil food and mold produces toxins that can cause foodborne illness. 2. Mold is found on bread, cheese, and fruit. 3. To avoid illness, throw out all moldy food, unless the mold is a natural art of the product (Cheese such as Brie and Gorgonzola.) 4. The Food and Drug Administration (FDA) recommends cutting away any moldy areas in hard cheese at least one-inch (2.5centimeters) around them.
Yeast: 1. Some yeast can cause food spoilage. 2. Yeast is found in jelly, jam, honey and syrup. 3. Contamination appears as bubbles, an alcohol smell or taste, discoloration or slime. 4. Food that has been spoiled by yeast should be discarded.
Let's pause here for a second to
look at the difference between Spoilage vs. Contamination • Contamination - is the presence of harmful substances or disease-causing microorganisms in food.
Parasites
Anisakiasis simplex is a worm-like parasite found in certain fish and shellfish. An illness can develop when raw or undercooked seafood containing the parasite is eaten. It can be either invasive or noninvasive. In its noninvasive form, the person coughs the parasite from the body. In the invasive form, the parasite penetrates the lining of the stomach or small intestine and must be surgically removed.
Prevention of Anisakiasis
Also if fish will be served raw or undercooked:
4. Ensure sushi-grade fish has been frozen by the supplier to the proper time-temperature requirements. To destroy parasites, raw fish, like sushi, must be frozen to -4° F or below for 168 hours (that is 7 days... one week). (molluscan shell fish and certain Tuna species are exempt.)
Special Rules for Highly Susceptible Population (HSP)
Definition of Highly Susceptible Population: Groups of people at high risk for foodborne illness due to age or health status, such as very young children, pregnant women, older people, people taking certain medications and those with certain disease or weakened immune systems. What are some examples of highly susceptible populations? • Patients in Hospitals • Occupants of Nursing homes • Young children i.e. Day Care Centers
When preparing foods for those at high risk it is important to remember to make sure that potentially hazardous foods are cooked to the recommended minimum internal temperature.
HSP Requirements for food establishments
(*Pasteurized - food that is heat-treated at very high temperatures to kill microorganisms.)
1. Apple juice beverages
2. Pasteurized eggs, egg
products
3 Food in unopened original packages Although, packaged food, like small packages of breadsticks or unopened individual packets of jelly, may be re-served in a “normal” restaurant, they can not be re-served to a highly susceptible population (HSP).
4. Raw animal foods
5. Baby food & formulas Cannot be received, sold or served past its expiration date.
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