Food Safety and Food Preservation

Food Safety Concerns

Introduction to Food Safety

• Learning Outcomes:
  • Identify the most common cause of food-borne disease outbreaks in the United States.
  • Explain the difference between a food-borne infection and a food-borne intoxication.
• Key Terms:
  • Food-borne illness: disorder that is caused by consuming disease-causing agents in food or water
  • Pathogens: disease-causing agents
  • Food-borne infection: illness that results when a pathogen in food inflames the intestinal tract or other body tissues
  • Food intoxication: illness that results when poisons produced by certain microbes contaminate food and irritate the intestinal tract
• Norovirus:
  • In the U.S., norovirus is the most common cause of food-borne illness outbreaks.
  • Signs & symptoms of norovirus include stomach pain, diarrhea, and vomiting.
  • Importance of good personal hygiene: People who are infected with norovirus will have the virus in their vomit and feces and can infect others if they do not wash their hands thoroughly after vomiting or having bowel movements.

Protecting Our Food

• Learning Outcomes:
  • Identify government agencies that are responsible for ensuring the safety of the food supply in the United States.
  • Discuss the roles of the FDA, FSIS, and EPA.
• U.S. Food and Drug Administration (FDA) and Department of Agriculture (USDA) regulate food industry:
  • FDA regulates nearly all food sold in interstate trade.
  • Establishes standards for safe food manufacturing
  • HACCP
• USDA’s Food Safety and Inspection Service (FSIS):
  • Enforces food safety laws for domestic and imported meat and poultry
• Environmental Protection Agency (EPA):
  • Monitors quality of drinking water
  • Regulates toxic substances and wastes
• Local and state health departments

Pathogens in Food

• Learning Outcomes:
  • Discuss ways that pathogens can contaminate human foods.
  • Explain how cross-contamination of food occurs.
  • Discuss the purpose of pasteurization.
  • Discuss conditions that favor the survival and multiplication of food-borne pathogens.
  • Identify foods that are high risk for supporting pathogens.
• Certain food microbes are beneficial and desirable:
  • Production of a variety of foods
  • Microbes alter the color, texture, taste, and other factors in production. Examples: hard cheese, raised bread, or alcoholic beverages
• Other microbes contaminate food, making it unsafe for humans:
  • Contaminants include pathogens, insect parts, pesticide residues, and metal fragments.
• Parasites are agents of infection in food or water.
  • Can live in a host organism, deriving nourishment from the host
• Sources of Pathogens:
  • The pathogens that cause food-borne illness can live practically anywhere—in air, water, soil, sewage, and on various surfaces.
  • Our skin, nasal passages, and large intestine have vast colonies of various kinds of microbes, some of which can be pathogenic.
  • Animals can also harbor harmful microbes or parasites on and in their bodies, especially in their intestinal tracts.
• Common Routes for Transmitting Pathogens
  • Vermin: Animals such as flies, cockroaches, mice, and rats that live around sewage or garbage
  • Poor personal hygiene: Failure to wash hands after using the toilet or coming in contact with sources of pathogens
  • Improper food handling: Cross-contamination or failing to keep foods at the proper temperatures
• High-Risk Foods:
  • To survive and multiply, pathogens need warmth, moisture, a source of nutrients, and sometimes oxygen.
  • In general, high-risk foods are warm, moist, protein-rich, and have a neutral or slightly acidic pH.
  • Refer to Table 12.1 for foods that are often risky.

Food-Borne Illness

• Learning Outcomes:
  • Describe typical signs and symptoms of food-borne illness.
  • Explain when a person who has a food-borne illness should seek professional medical help.
  • Explain why it is incorrect to call a food-borne illness the “flu” or “stomach flu.”
• COVID-19:
  • Nausea, vomiting, and diarrhea are common signs and symptoms of food-borne illness.
  • There is no evidence that COVID-19 is a food or water-borne illness, though it can have gastrointestinal symptoms.
  • The virus that causes COVID-19 needs living cells to survive.
  • Following basic food safety measures is still prudent before preparing and eating food.
• Food-Borne Illness:
  • Illnesses generally involve the digestive tract; signs and symptoms include nausea, vomiting, diarrhea, and intestinal cramps.
  • The number of pathogenic microbes or amount of toxin they may form influences whether a person becomes ill.
  • High-risk populations include pregnant women, very young children, older adults, and people who have serious chronic diseases or weakened immune systems.
• Serious Signs & Symptoms:
  • If severe, hospitalization may be required. Consult a physician when an intestinal disorder is accompanied by: severe intestinal pain, fever (temperature above $102^\circ F$), bloody bowel movements, prolonged vomiting that reduces fluid intake, diarrhea that lasts more than 3 days (adults), and dehydration.
  • See Table 12.2 for these and other serious signs and symptoms.
• Is It the “Stomach Flu?”:
  • The “flu” is influenza, caused by specific viruses that infect the respiratory tract, characterized by coughing, fever, weakness, and body aches.
  • Gastrointestinal disturbances are not typical signs of influenza.
  • Food-borne illnesses: Pathogens infect the intestinal tract and generally do not have respiratory signs and symptoms.

Common Food-Borne Pathogens

• Learning Outcomes:
  • Identify common pathogens that are sources of food-borne illness in the United States.
  • Discuss typical signs, symptoms, and incubation periods of food-borne illnesses that are caused by each major pathogen.
  • Identify foods that are often sources of pathogens or their toxins.
• Common Food-Borne Pathogens:
  • Bacteria: simple, single-celled microorganisms
  • Viruses: microbe consisting of a piece of genetic material coated with protein; invade living cells to reproduce
  • Fungi: live on dead/decaying matter
  • Protozoa: single-celled microorganisms that have a more complex cell structure than bacteria
  • Parasitic worms: obtain nourishment from living in a host
• Common Sources of Food-Borne Illness: Bacteria
  • Campylobacter
  • Clostridium
  • Escherichia
  • Listeria
  • Salmonella
  • Staphylococcus
  • See Table 12.3 for more information about pathogenic bacteria.
• Common Sources of Food-Borne Illness: Viruses
  • Norovirus
  • Rotavirus
  • Hepatitis A
  • See Table 12.4 for more information on these viruses.
• Sources of Food-Borne Illness: Fungi
  • Toxic wild mushrooms
  • Molds that produce aflatoxins
  • Outbreaks of food-borne illness caused by fungi are rare in the U.S.
• Sources of Food-Borne Illness: Protozoa & Parasitic Worms
  • Protozoa: Giardia, Cryptosporidium, Toxoplasma
  • Parasitic worms: Trichinella, Anisakis
  • See Table 12.5 for more information about pathogenic protozoa and worms.

Preventing Food-Borne Illness

• Learning Outcomes:
  • Explain how to reduce the risk of food-borne illness when purchasing, preparing, cooking, and storing foods and beverages.
  • Explain why ground meat and poultry often are sources of food-borne illness.
  • Identify the temperature range that encourages rapid multiplication of pathogens.
  • Discuss the food safety educators’ four simple actions for reducing the risk of food-borne illness.
• Reducing Risk When Purchasing Food
  • Select frozen foods and highly perishable foods (meat and fish) last.
  • Check “best by” dates on perishable foods.
  • Do not buy food in damaged containers or egg cartons with cracked eggs.
  • Purchase only pasteurized milk, cheese, and fruit and vegetable juices.
  • Pack meat, fish, and poultry in separate plastic bags.
• Reducing Risk: Storing Food
  • Take groceries home immediately after shopping and store promptly.
  • Store whole eggs in their cartons.
• Before Preparing Food
  • Wash hands thoroughly with warm soapy water for at least 20 seconds before and after touching food.
  • Clean food preparation surfaces with hot soapy water before preparing food.
  • Use cutting boards with unmarred surfaces made of plastic, marble, or glass.
  • Have separate cutting boards for meats/fish/poultry, fruits/vegetables, and breads.
  • Sanitize food preparation surfaces and equipment that have come in contact with raw meat, fish, poultry, and eggs as soon as possible.
• Reducing Risk: Preparing Food
  • Do not use foods from containers that leak, bulge, or are severely dented, or jars that are cracked or have loose or bulging lids.
  • Do not use food from containers that have damaged safety seals.
  • Do not taste or use food that spurts liquid or has a bad odor when the can is opened.
  • Read product labels to determine proper storage conditions.
• Safe Food Preparation Tips
  • Wash fresh produce under running water to remove surface dirt and bacteria.
  • Avoid eating moldy foods; small amounts of mold on hard cheeses and firm fruits/vegetables can be cut away with at least 1 inch of surrounding food.
  • Remember: When in doubt, throw it out.
• Proper Temperature of Foods
  • Danger zone: According to HHS and USDA, most microbes grow well when food temperatures are between $40^\circ F$ to $140^\circ F$.
  • Cooking food to the proper internal temperature destroys food-borne pathogens.
  • Microwave cooking can result in uneven temperatures that may not destroy all pathogens.
• Safe Minimum Internal Temperatures (Table 12.6)
  • Beef steaks & roasts: $145^\circ F$
  • Fish: $145^\circ F$
  • Pork: $145^\circ F$
  • Ground beef or pork: $160^\circ F$
  • Egg dishes: $160^\circ F$
  • Poultry: $165^\circ F$
• More Food Safety Tips
  • Always thaw high-risk foods in the refrigerator, under cold running water, or in the microwave; cook foods immediately after thawing.
  • Marinate food in the refrigerator and discard the marinade from meat, fish, or poultry.
  • Serve meat, poultry, and fish on a clean plate; never use the same plate that held the raw product.
  • Keep cold foods cold, hot foods hot.
• Raw Fish
  • Eating raw fish can be safe for most healthy people if the fish is very fresh, commercially frozen, and properly thawed.
  • Purchase from reputable establishments with high standards for quality and sanitation.
  • It is prudent to avoid eating any raw animal products, including fish.
• Ground Meats, Poultry and Fish
  • Ground meats and poultry are very perishable and must be thoroughly cooked.
  • Cook beef, poultry, pork, thick pieces of fish, and egg-containing dishes thoroughly; cook eggs until the yolk and white solidify.
  • Do not wash poultry before cooking it.
  • Stuff the bird immediately before cooking; temperature of the stuffing should reach $165^\circ F$ or bake the stuffing separately.
• Cooling
  • Food-borne pathogens thrive at “room temperature,” between $60^\circ F$ and $110^\circ F$.
  • Refrigerate or freeze leftover foods within 2 hours of serving, or within 1 hour if environmental temperatures are >$90^\circ F$.
  • Separate food into shallow pans to ensure faster cooling.
• Perishables
  • Cook or freeze ground meats and poultry soon after purchasing.
  • Cook raw fish, shellfish, and poultry the day they are purchased.
  • Use refrigerated ground meat within 1 to 2 days, and use frozen meat and patties within 3 to 4 months after purchasing them. See Table 12.7 for cold storage time limits
  • Use refrigerated leftovers within 4 days.
• Four Simple Actions
  • CLEAN: Wash hands & surfaces often.
  • SEPARATE: Do not cross-contaminate.
  • COOK: Cook to proper temperature.
  • CHILL: Refrigerate promptly.

Food Preservation

• Learning Outcomes:
  • Discuss food preservation methods, including how each method extends the shelf life of foods.
  • Explain how to prepare home-canned, low-acid foods that are safe to eat.
• Key Terms:
  • Shelf life: period of time that a food can be stored before it spoils
  • Fermentation: process used to preserve or produce a variety of foods, including pickles and wine
  • Sterilization: process that kills or destroys all microorganisms and viruses
• Food Preservation Methods
  • Heating, adding salt or sugar, smoking, curing, chilling/freezing, drying, fermenting, canning, irradiating. See Table 12.8.
• Home-Canned Foods
  • Home-canned foods may contain Clostridium botulinum and its deadly toxin; low-acid foods, such as corn and beans, are most susceptible.
  • Do not taste home-canned, low-acid foods before they are boiled for at least 10 min.
• Irradiation
  • Food irradiation preserves food by using a high amount of energy to kill pathogens; it does not make foods radioactive.
  • Used on spices, dry vegetable seasonings, meats, seeds, shell eggs, and fresh produce.
  • See Table 12.9 for list of foods approved for irradiation in the U.S.
  • Irradiated foods (except dried seasonings) must have the Radura symbol on package.

Preparing for Disasters

• Learning Outcomes:
  • Explain actions people in households can take to have safe food and water available after a disaster.
  • Discuss ways to safely prepare food when a power outage occurs.
• Emergency Water Supply
  • Store at least one gallon of water/person/day; keep a 3- to 5-day supply.
  • Keep water in a cool place and in sturdy plastic containers; change stored water every 6 months.
  • Drink only bottled, boiled, or treated water until public water supply is safe.
  • If there is time to prepare, fill a bathtub with water to use, after it is sanitized.
  • Make sure the seal on bottled water has not been broken.
• Emergency Food Supply
  • Store at least a 3-day supply of food for emergency use (see Table 12.10 for foods to store).
  • Choose foods that have a long storage life, require no refrigeration, or cooking.
  • Store a manual can opener, paper plates, and eating utensils.
  • If electrical service is disrupted, eat foods from the refrigerator and freezer before eating the emergency food supply.
  • NEVER use a camp stove or charcoal grill indoors—produces toxic carbon monoxide gas.

Food Additives

• Learning Outcomes:
  • Explain the difference between direct and indirect food additives, and provide examples of each type of additive.
  • Discuss the impact of the GRAS list and the Delaney Clause on the use of food additives.
  • Identify unintentional food additives.
  • Discuss pesticides, including the pros and cons of their use.
  • Explain the usefulness of integrated pest management.
• Food Additives
  • Food additive: any substance that becomes incorporated in food during production, packaging, transport, or storage
    • Direct (intentional) additives are added to foods for a particular purpose (see Table 12.11).
    • Indirect additives enter food but have no purpose (contaminants).
• Food Safety Legislation: Food Additives
  • Food Additives Amendment (1958)
    • Required manufacturers to provide evidence that a new additive is safe before use in products
    • Generally Recognized as Safe (GRAS): List of ingredients used before 1958 that were thought to be safe and exempt from safety testing.
    • GRAS list substances are not classified as additives; all new additives must undergo safety testing before FDA grants approval.
• Food Safety Legislation: Food Additives
  • Delaney Clause of the Food Additives Amendment
    • Prevents manufacturers from adding a new compound to foods that causes cancer at any level of intake (does not apply to pesticide residues).
  • The Food Quality Protection Act of 1996 established safety standards of “a reasonable certainty of no harm” for pesticide residues.
• Other Substances in Foods
  • FDA does not permit adulterated foods to be sold.
  • Unintentional food additives are substances that get into foods accidentally.
    • FDA cannot ban unintentional additives but permits very small amounts of unavoidable, naturally occurring substances, such as dirt and insect parts in foods, which are not harmful when consumed in minute amounts.
  • Chemical contaminants (e.g., lead or mercury) are naturally in our environment and may be in foods.
• Human-Made Compounds
  • Poisonous benzene and polychlorinated biphenols (PCBs) are in the environment, resulting from human manufacturing practices, and can pollute sources of water used by consumers (e.g., well water).
  • Americans who drink water from municipal supplies can be assured that the water is analyzed regularly to determine its concentrations of toxic substances.
• What Are Pesticides?
  • Pesticides: any substances used to control or kill unwanted organisms
    • Insecticides: control or kill insects
    • Rodenticides: control or kill mice and rats
    • Herbicides: destroy weeds
    • Fungicides: limit spread of fungi
  • Pesticide Residue Tolerances: maximum amount of pesticide residues allowed
• How Safe Are Pesticides?
  • Pesticides have the potential to harm humans, animals, and the environment.
    • Once pesticides are applied to crops, they may remain in the soil, be taken up by the plant root, enter groundwater and other waterways, or be carried to other locations by the wind – each path can be a route to the human food chain.
  • Integrated Pest Management uses methods of controlling pests that limit environmental damage.

Nutrition Matters: Avoiding “The Revenge”

• Learning Outcomes:
  • Discuss ways to prevent traveler’s diarrhea.
  • Identify nations where visitors are most likely to develop traveler’s diarrhea.
• Traveler’s Diarrhea (TD)
  • Bacterial pathogens account for 80 to 90% of cases; protozoa (e.g., Giardia) account for about 10% of cases.
  • TD results from consuming food or water that has been contaminated with pathogens, causing abrupt onset of abdominal cramps, loose or watery bowel movements, nausea, vomiting, bloating, and fever.
  • Bacterial infections generally last 3 to 5 days.
• Reducing Your Risk of TD
  • High-risk regions have high population densities, widespread pollution, and inadequate water treatment systems:
    • Mexico and other parts of Central America
    • Most of Asia, the Middle East, Africa, and South America
• What's Generally Safe to Eat?
  • Less Safe:
    • Unpasteurized dairy products, food from street vendors, unwashed/unpeeled raw fruits and vegetables, raw/undercooked meat or fish, water or ice made from tap/well, fountain drinks, salads, raw/soft-cooked eggs, flavored ice pops, food served at room temperature.
  • Safer:
    • Pasteurized dairy products, "dry" foods (bread/crackers), bottled/sealed water/soft drinks/sports drinks, hot coffee/tea, hard-cooked egg, food cooked and served hot, thoroughly cooked meat, food from factory-sealed container, washed/peeled fruits and vegetables.
• Sanitizing Drinking Water
  • Boiling: for at least one minute
  • Chemical disinfectants: containing chlorine (e.g., bleach) or iodine (drops or tablets; follow manufacturer’s instructions)
  • Filtering water: removes bacteria and protozoa but may not remove viruses
• Preventive Medication
  • Consult a physician before traveling to a high-risk area.
  • Bismuth subsalicylate (BSS) can reduce the risk but has side effects, including nausea, constipation, and blackening of the tongue and bowel movements; not recommended for children under 12 years of age.
• Treating TD
  • Prescribed antibiotics are the main treatment and are effective against bacterial infections.
  • Antimotility agents; fluids & electrolytes to prevent dehydration