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Chapter 12 Food Safety and Food Technology


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Title: Chapter 12 Food Safety and Food Technology

Chapter 12Food Safety and Food Technology
Agencies That Monitor The U.S. Food Supply
  • CDC (Center for Disease Control and Prevention)
    Dept. Health and Human Services-monitors
    foodborne illness
  • EPA-regulates pesticides and water quality
  • FDA- (HHS) responsible for all food safety and
    wholesomeness except eggs, meat and poultry
  • USDA-Responsible for meat, poultry and eggs

Food Safety
  • Harmful substances in foods
  • Pathogens
  • Bacteria, viruses, parasites
  • Some common pathogens causing foodborne illness
  • Staphylococcus aureus, Clostridium botulinum,
    Salmonella, Escherichia coli
  • Chemical contamination
  • Pesticides
  • Animal drugs
  • Pollutants
  • Natural toxins
  • Methyl mercury
  • Poisonous plants
  • Solanine

Microbes and Food Safety
  • Foodborne illnesses can be life-threatening
  • Especially to the ill, the malnourished, those
    with a compromised immune system, pregnant women,
    infants, children and the very old
  • Each year in the United States, an estimated 76
    million people become ill from foodborne diseases
  • 5,000 of them die

Microbes and Food Safety
  • Symptoms of foodborne illness
  • Bloody stools
  • Diarrhea of more than 3 days duration
  • Fever of longer than 24 hours duration
  • Headache accompanied by muscle stiffness and
  • Numbness, muscle weakness, tingling sensations in
    the skin
  • Rapid heart rate, fainting, dizziness
  • Majority of food-poisoning cases
  • Result of errors consumers make in handling foods
    after purchase
  • Commercially prepared food is usually safe
  • If digestive tract disturbances are the only
    major symptom of your next bout of stomach flu
    chances are it was foodborne illness

Food Safety
  • Raw meats can contain live, disease-causing
  • Thorough cooking makes them safe
  • In the mid-1990s a fast-food restaurant chain in
    the Northwest served undercooked hamburgers from
    meat contaminated with bacterium E. coli 0157H7
  • 4 people died
  • 100s of patrons became seriously ill
  • As a result more Government Inspections and
    Industry controls were set up through the Hazard
    Analysis Critical Control Point (HACCP) plan

Food Safety
  • By law, U.S. producers and handlers of meat,
    poultry, seafood, fresh fruit, and vegetable
    juices must employ a Hazard Analysis Critical
    Control Point (HACCP) plan
  • Since the implementation contamination of poultry
    has declined by 50, ground beef by 40, pork by
  • USDA inspectors increased
  • FDA inspectors decreased

Food Safety
  • Consumer Protection
  • The safety of canned and packaged foods sold in
    grocery stores is controlled through sound food
    technology practices
  • Large-scale commercial incidents make up only a
    fraction of the nations total food-poisoning
    cases each year
  • The vast majority of cases arise from one
    persons error in a small setting
  • Affect just a few victims

Food Safety
  • Food can provide ideal conditions for bacteria to
    thrive or produce toxins
  • Disease-causing bacteria require
  • Warmth
  • 40F - 140F 4C - 60C
  • Moisture
  • Nutrients
  • To control bacteria
  • Keep hot food hot-above 140F
  • Keep cold food cold-below 40F/4C
  • Keep raw foods separate
  • Keep your hands and the kitchen clean

Food Safety
  • Keep Hot Food Hot
  • Keep cooked foods at 140F or higher until served
    cooking does not destroy all bacterial toxins
  • If handled improperly can cause illness
  • Cooked foods should be refrigerated immediately
    or within two hours at the maximum
  • Keep Cold Food Cold
  • Start when you leave the grocery store
  • At home, put foods into the refrigerator or
    freezer immediately
  • When defrosting foods
  • Thaw meats or poultry in the refrigerator
  • Marinate meats in the refrigerator

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Food Safety
  • Food with an off appearance or odor should not
    be used or tasted
  • Keep raw foods separate /Prevent
  • Raw foods, especially meats, eggs and seafood,
    are likely to contain bacteria
  • Keep the raw foods and their juices away from
    ready-to-eat foods
  • After handling raw foods wash surfaces your
    hands, thoroughly with soap
  • Foods prone to microbial growth
  • Those high in moisture and nutrients
  • Those chopped or ground like meats and poultry

Food Safety
  • Treat kitchen utensils with heat
  • Soapy water heated to 140F kills most harmful
  • Water must be scalding hot, well beyond the
    temperature of the tap
  • Automatic dishwasher
  • Uses water hotter than hands can tolerate
  • Most dishwasher detergents contain chlorine
  • Sponges
  • Place wet sponges in a microwave and heat it
    until steaming hot
  • Make use of antibacterial cleaners, sponges,
    cloths, boards, or utensils

Foods That Make People Sick
  • Cryptosporidium-300,00 ill/7deaths 2-10days
  • 1993/ affected 400,00 100 deaths Milwaukee
  • Hepatitis A-4200 ill/4 deaths 15-58 days
  • Listeria-2,500 ill/500 deaths 7-30 days
  • E. Coli -62,500 ill/50 deaths
  • Salmonella -1-34 million/500 deaths 1-3 days
  • Stomach Flu/Norovirus 9.2 million/124 deaths
  • 12-24hr
  • Traveler Diarrhea/ Giardia and other protoza 10
    million 2 days-several weeks
  • Botulism-60/4 deaths 12-72 hours
  • Staphycoccus 185,000/2 deaths ½ hour-8hr

Foods That Make People Sick
  • Bovine Spongiform Encephalopathy (BSE) Mad Cow
  • Not related to sanitation
  • A disease of cattle linked with a rare but fatal
    human brain disorder
  • Can lie dormant in the body for many years before
    symptoms arise
  • BSE is caused by a protein, known as a prion
  • Cannot be killed or controlled through cooking or
  • The bodys immune system doesnt rid the body of
  • Little is known about how prions cause diseases
  • Found in people who consumed products from
    infected animals
  • To date Fewer than 150 people, most in Great
    Britain have been diagnosed

Foods That Make People Sick
  • The USDA has enacted protective measures
    targeting BSE
  • Prohibiting the use of downer cattle (unable to
    walk) for human consumption
  • Increasing BSE testing of cattle at slaughter
  • At risk are
  • Imported supplements made from glands of animals
    often sold as hormone preparations

Foods That Make People Sick
  • Eggs
  • Raw, unpasteurized eggs are likely to be
    contaminated by Salmonella bacteria
  • Raw pasteurized egg substitutes may contain a few
    live bacteria
  • They may not be safe for pregnant women, the
    elderly, the very young, or those suffering from
    immune disorders
  • Raw Produce
  • Fruits and vegetables are a microbial threat
    unless they are thoroughly rinsed in running cold
  • Ten years ago, meats, eggs, and seafood posed the
    greatest foodborne illness threat
  • Today produce equals them

Foods That Make People Sick
  • Seafood
  • Worms, Flukes, Viruses, and Naturally occurring
  • Dangers posed by seafood have grown in recent
  • Offshore waters are becoming more polluted
  • Viruses that cause human diseases have been
    detected in 90 of water off the U.S. coast

Foods That Make People Sick
  • Honey
  • Can contain dormant spores of Clostridium
    botulinum that become active in the human body
    produce a toxin
  • Adults are usually protected
  • Infants under one year of age should never be fed
  • Picnics, Lunch Bags, and Take-Out Foods

Illness When Traveling
  • People who travel to places where cleanliness
    standards are lacking can get Travelers diarrhea
  • Before you travel, ask your physician which
    medicines to take with you in case you get sick
  • Wash your hands often with soap and water
  • Eat raw fruits and vegetables only if you have
    washed them with your clean hands in boiled water
    and peeled them yourself
  • Skip salads
  • Water, ice, and beverages made from water may be
  • Take along disinfecting tablets
  • Drink only treated, boiled, canned, or bottled
    beverages without ice
  • Use when brushing your teeth

Natural Toxins in Foods
  • Belladonna and hemlock
  • Plants that are deadly poisons
  • Sassafras
  • Contains a cancer-causing agent
  • Banned from use in commercially produced foods
    and beverages
  • Cabbage, turnips, mustard greens, and radishes
  • Contain small quantities of goitrogens
  • Compounds that can enlarge the thyroid gland and
    aggravate thyroid problems

Natural Toxins in Foods
  • Raw lima beans, cassava apricot pits
  • Contain precursors to cyanide
  • Potatoes
  • Contain solanine a bitter, narcotic-like
  • Can build up to toxic levels when potatoes are
    exposed to light during storage
  • Found in a green layer that develops just below
    the skin that can be peeled off
  • Seafood
  • Contains redtide toxin that occurs during algae
  • The red tide causes a form of food poisoning that
    paralyzes the eater

Irradiation and Food Safety
  • Potential Benefits of Food Irradiation
  • Kills almost all disease-producing microorganisms
    present in food
  • Reduces the incidence of foodborne illness
  • Reduces the destruction of food by pests
  • Can kill most microbes even while food is in a
    frozen state
  • Irradiated raw poultry is 99.9 free of
    disease-causing microorganisms, reducing the risk
    of cross-contamination
  • Has no effect on most toxins, prions, and
    microbial spores

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Irradiation and Food Safety
  • Foods approved for radiation
  • Citrus fruits, eggs, frozen and fresh meats,
  • mushrooms, potatoes, onions, poultry, spices,
  • strawberries, tomatoes, tropical fruits, wheat
  • Labeling of Irradiated Foods
  • Required by the FDA
  • No label is required for foods containing
    irradiated ingredients and for irradiated foods
    served in restaurants

Irradiation and Food Safety
  • Consumer fears about safety
  • Foods will become radioactive
  • Foods will lose nutrients
  • Foods will not be safe to eat
  • Harmful chemicals will form
  • People will be endangered-- plant workers, the
    general population
  • The environment will be effected

Irradiation and Food Safety
  • Irradiations Effects on Nutrients
  • Most nutrients, as proteins, fats, carbohydrates,
    and minerals, survive irradiation intact
  • Nutrients sensitive to heat treatment, such as
    the B vitamins and ascorbic acid, are sensitive
    to irradiation
  • Irradiation Safety
  • More than 40 years of research on animals have
    revealed no toxic effects from eating irradiated
  • Studies of human volunteers who ate a diet
    composed entirely of irradiated foods found no
    ill effects

Irradiation and Food Safety
  • Consumers The Final Authority
  • Whether irradiated foods will appear in markets
    depends upon whether consumers choose to buy them
  • According to a national survey those willing to
    purchase irradiated foods declined during the
    past decade from 70 to about 50
  • Cost is a big factor

Residues and Contaminants in FoodsPesticides
  • Chemicals used to control insects, diseases,
    weeds, fungi, and other pests on crops and around
  • Includes herbicides, insecticides, and fungicides
  • Used to ensure the survival of food crops
  • Accumulates in the food chain
  • Kill pests natural predators
  • Pollute the water, soil, and air

Residues and Contaminants in Foods Pesticides
  • Do Pesticides on Foods Pose a Hazard to
  • Many pesticides are broad-spectrum poisons that
    damage all living cells not just pests
  • Their use poses hazards to the plants and animals
    and workers involved with pesticide production,
    transport, and application
  • High doses of pesticides applied to laboratory
    animals cause
  • Birth defects, Sterility, Tumors, Organ damage,
    Central nervous system impairment
  • Pesticide residues on agricultural crops can
    survive processing and may be present in and on
    foods served to people

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Residues and Contaminants in Foods Pesticides
  • Infants and children may be more vulnerable to
    adverse effects
  • Their brains cannot exclude pesticides and other
    chemicals to the same extent as the adult brain

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Residues and Contaminants in Foods Pesticides
  • A loophole in federal regulations allows
    companies in the U.S. to make banned pesticides
    and export them to other countries
  • The banned pesticides can then return to the U.S.
    in imported foods

Residues and Contaminants in Foods Pesticides
  • Possible Alternatives to Pesticides
  • Manage pests by using a combination of natural
    and biological controls
  • Natural Pesticides are uses in organic farming
  • nicotine (tobacco)
  • psoralens (celery)
  • Organic foods
  • Foods grown and processed without the use of
    synthetic chemicals such as pesticides,
    herbicides, fertilizers, or without genetic
    engineering or irradiation

Residues and Contaminants in Foods Animal Drugs
  • Bovine somatotropin (bST) growth hormone
  • Produced by genetically modified bacteria
  • Cattle are injected with growth hormone
  • FDA considers the practice safe does not
    require testing of food products for traces
  • bST use
  • Promotes lean tissue growth
  • Increases milk production
  • The European Union and Canada ban the use of bST
    for milk cows

Residues and Contaminants in Foods Animal Drugs
  • Antibiotics in Livestock
  • Often given as part of a daily feeding regimen
  • Prevent infections to the animals living in
    crowded conditions and promotes rapid growth
  • By law there is a waiting period before slaughter
    so the drugs break down
  • Consumers face little threat of getting
    antibiotics in meats, milk, and eggs
  • The greater risk is illness from
    antibiotic-resistant bacteria when animals are
    treated with daily antibiotics

Environmental Contaminants
  • Contaminant
  • Any substance occurring in food by accident or
    not normally present
  • Some contaminants resist breakdown in the body
    and are not metabolized or excreted
  • Some (mercury) can pass from one species to
    another and accumulate at higher concentrations
  • Chemical contaminants of concern in foods
  • Heavy metals Arsenic, Cadmium, Lead, Mercury,
  • Halogens Chlorine, Ethylene dichloride, Iodine,
    PBB, PCBs, TCE, Vinyl chloride
  • Others Acrylamide, Antibiotics (in animal feed),
    DES, Dioxins

Environmental Contaminants
  • Mercury
  • All fish have at least trace amounts of mercury
    and other contaminants (PCBs, dioxins, and DDT)
  • The FDA and EPA warns of high methylmercury
    levels in fish and other seafood
  • They advise all pregnant women, nursing mothers,
    and young children against eating fish species
    high in methylmercury

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Effects of Food Processing on the Nutrients in
  • Consumers rely on packaged and processed foods
  • On the positive side it makes food safer and
    gives food a longer useable shelflife by
  • Microbial growth
  • Oxidative changes
  • Enzyme destruction
  • On the negative side some vitamins and minerals
    are lost
  • Pasteurization makes milk safe to drink
  • Worth the nutrient loss
  • Boxes of milk that can be kept at room
    temperature have been treated with ultrahigh
    temperature (UHT)

Effects of Food Processing Extended Shelf Life
  • Modified atmosphere packaging (MAP)
  • Perishable food is packaged in a container from
    which air is removed (vacuum packed) or another
    gas mixture has been added to exclude oxygen
  • Slows ripening of fruits and vegetables
  • Reduces spoilage by mold and bacterial growth
  • Prevents discoloration of cut vegetables and
  • Prevents spoilage of fats by rancidity
  • Slows development of off flavors
  • Slows enzymatic breakdown of vitamins

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Effects of Food ProcessingCanning
  • Protects against microbes but has fewer nutrients
  • High heat/short time
  • Fat soluble vitamins and minerals are not
  • Affected Thiamin, Riboflavin and Vitamin C
  • Minerals and water soluble vitamins are lost in
    the water

Effects of Food Processing Freezing
  • Lowers the foods temperature to a point that
    stops life processes
  • Microorganisms do not die but remain dormant
    until the food is thawed
  • Slows enzymatic reactions
  • Nutrient contents are similar to those of fresh
  • Often contain more nutrients than fresh fruits
    and vegetables that have stayed in the produce
  • Foods frozen have to be kept solidly frozen at
    0F, to be safe and retain their nutrients
  • If foods defrost slightly but ice crystals remain
    - It is probably safe to refreeze the food for
    later use

Effects of Food Processing Drying
  • Drying
  • Preserves food by removing water to inhibit
    microbial growth
  • Commercial drying does not cause major nutrient
  • Sulfite additives
  • Used for drying fruits
  • Prevent browning
  • Helps preserve vitamin C
  • Some people suffer severe allergic reactions when
    they consume sulfites

Food Additives
  • What are food additives?
  • Substances added to foods that are not eaten by
    themselves as foods
  • Additives give foods desirable characteristics
    Color, Flavor,
    Texture, Stability, Resistance to spoilage
  • The FDA decides what additives shall be in foods
  • All are periodically reviewed
  • None are permanently approved
  • Compared to the unregulated and untested
    dietary supplements sold directly to consumers,
    the 3,000 food additives in the U.S. are strictly

Food Additives
  • Antimicrobial agents
  • Antioxidants
  • Artificial colors
  • Artificial flavors, flavor enhancers
  • Bleaching agents
  • Chelating agents
  • Nutrients
  • Preservatives
  • Thickening and stabilizing agents

Food Additives Antimicrobial Agents--Preservative
  • 1. Salt and Sugar --most widely used
  • Salt is used to preserve meat and fish
  • Sugar preserves jams, jellies, and canned and
    frozen fruits
  • Salt and sugar withdraw water from food -Microbes
    cannot grow without water
  • 2. Potassium sorbate sodium propionate
  • Extend the shelf life of baked goods, cheese,
    beverages, mayonnaise, margarine
  • 3. Nitrites
  • Added to meats and meat products to preserve
    color, enhance flavor, retard bacterial growth

Food Additives
  • 4. Sulfites
  • Prevents oxidation in processed foods, alcoholic
    beverages, and drugs
  • Were used to keep raw fruits and vegetables in
    salad bars looking fresh
  • Banned after a few people experienced dangerous
    allergic reactions
  • 5. BHA and BHT
  • Prevent rancidity in baked goods and snack foods
  • 6. Food coloring
  • makes foods look attractive
  • 7. Artificial flavors
  • - 2,000 flavors and enhancers are approved
  • 8. MSG produces adverse reactions in some people
  • - Flavor enhancer

Food Additives
  • 9. Incidental
  • Include bits of plastic, glass, paper, tin from
    packages and chemicals from processing, such as
    solvents used to decaffeinate coffees
  • Dioxins are found in coffee filters, paper milk
    cartons, paper plates, and frozen food boxes made
    of bleached paper
  • 10. Nutrients
  • Iodine added to salt
  • Vitamins A and D added to dairy products
  • Nutrients used to enrich and fortify breakfast
    cereals and grains
  • Vitamins C and E used as antioxidants
  • Beta-carotene as a colorant

Regulations Governing Additives
  • The GRAS list (generally recognized as safe)
  • A list of 700 substances that were used routinely
    without any problems for many years. When
    substantial scientific evidence or public outcry
    has questioned the safety of a GRAS list additive
    its safety has been reevaluated by FDA.

Preserving Nutrients in Foods
  • Conserving Nutrients at Home
  • In modern commercial processing, losses of
    vitamins seldom exceed 25
  • Losses of 60 - 75 can occur during food
    preparation at home
  • Enzymes can cause destruction of vitamins
  • Breakdown of nutrients in fresh fruits and
    vegetables occurs at room temperature (70F).
    Chilling slows the breakdown.
  • Light and air cause the breakdown of some
    vitamins-Riboflavin is light sensitive (milk)
  • Refreezing causes texture and taste changes and
    loss of nutrient content

Preserving Nutrients in Foods
  • Minerals and water-soluble vitamins in
    vegetables dissolve in water in which they are
    washed, boiled, or canned
  • As much as half of the vitamins and minerals in
    foods go down the drain with the water
  • Ways to minimize cooking losses
  • Steam, stir-fry or microwave vegetables
  • Use the liquid in soup or stews

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Controversy Organic Foods And Genetically
Modified Foods What Are The Pros and Cons?
  • Organic food is one of the fastest growing
    segments of the food industry
  • At the same time, many U.S. farms have shifted
    toward growing foods altered through genetic
    engineering (GE)
  • 80 of soybeans, 40 of corn, 70 of cotton
  • Issues Surrounding Organic Foods
  • A farmer wishing to grow and market organic foods
    must receive certification by USDA inspectors
  • Food sold or labeled as organic, must be
    processed according to the procedures outlined in
    the following slide

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Organic Foods
  • Environmental Benefits
  • Organic foods are grown by using the techniques
    of sustainable agriculture
  • Vegetables and fruits are fertilized with
    composted animal manure or vegetable matter with
    no synthetic fertilizers that can run off into
    waterways and pollute them
  • No synthetic pesticides or disease-fighting
    agents are applied
  • Chemical impact on wildlife and humans is minimal

Organic Foods
  • Potential Health Risks
  • Organic foods may not be safer than conventional
  • Improperly composted manure fertilizer may expose
    consumers to microbial diseases
  • Unpasteurized organic juices, milk, and cheeses
    may be microbial hazards
  • Lack of preservatives causes more spoilage
  • Costs
  • Organic foods cost more than conventional foods

Genetically Modified Foods
  • Like organic food production, genetic engineering
    carries its own potential set of risks and
  • Unlike the tried and true organic foods, GE food
    varieties are new to the food supply

  • Genetic Engineering
  • The consumer may not be able to distinguish
    genetically altered food from food that has not
    been genetically altered because it bears no
    special labels

Genetically Modified Foods
  • Benefits of genetic engineering
  • Enhanced plant growth
  • Reduced pesticide and fertilizer use
  • Enhanced nutrient composition
  • Enhanced crop yields
  • Risks
  • Potential for new allergens
  • Herbicide resistant weeds
  • Loss of biodiversity

Genetically Modified Foods
  • Genetic Engineering Basics
  • Genetic engineering can change the genetic makeup
    of an organism in a year or two
  • Cross-breeding in nature and selective breeding
    in agriculture, is a lengthy process

Genetically Modified Foods
  • Plant genetics
  • Traditional breeding
  • Cross two plants, develop hybrids, takes time
  • Genetic engineering
  • Transform specific genes
  • Less time to get desiredeffects

Genetically Modified Foods
  • The Promises of Genetic Engineering
  • Supporters see it as a means of overcoming many
    of the planets pressing problems, such as
  • Food shortages
  • Nutrient deficiencies
  • Medicine shortages
  • Dwindling farmland
  • Environmental degradation

Genetically Modified Foods
  • New crops can now resist insects without sprays
  • Survive drought
  • Provide more complete sources of protein for
    people without access to animal products or
    adequate vegetable proteins

Genetically Modified Foods
  • GM Microorganisms can change production of foods
  • Bacteria can make the enzyme rennin needed in
    cheese production
  • In the past rennin was obtained from the stomachs
    of calves
  • GM bacteria produces human growth hormone
  • More children with growth hormone deficiency can
    grow normally
  • Others GM bacteria produce the hormone insulin

Genetically Modified Foods
  • The current manufacturing process of fortifying
    and enriching wheat, rice, grains, and milk
    products may become obsolete if rDNA added to
    plants and animals can make the extra nutrients
    in their tissues
  • Consumers may see favorite foods such as potatoes
    turned into functional foods that contain
    phytochemicals borrowed from foods such as

Genetically Modified Foods
  • Opposition to Biotechnology
  • Some fear that by tampering with the basic
    blueprint of life, genetic engineering will
    sooner or later unleash mayhem on an unsuspecting
  • Opponents view biotechnology firms as naïve and
    profit driven
  • Proponents of genetic engineering respond that
    most of the worlds people cannot afford the
    luxury of rejecting the benefits of technology

Genetically Modified Foods
  • Opponents point out that while rDNA technology
    benefits biotechnology companies and giant
    industrial farms, it has produced no real
    benefits for consumers and the risks are not
  • Others object to rDNA technology on religious
  • Holding that genetic decisions are best left to
    nature or a higher power

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