Food Safety Principles

Food Safety Principles

Controlling Contamination at the Food Source

Objectives

  • Understand the basic Food Microbiology principles used by the Food Industry to produce safe foods.

Why Food Companies Care About Foodborne Illness

  • Brand Equity: Foodborne illnesses can negatively impact a company's brand image.
  • Lawsuits: Potential legal action from consumers who get sick.
  • Jail Time: Possible incarceration for company officers in severe cases.
  • Financial Loss: Expenses related to product recalls.
  • Example:
    • Peanut Corporation of America (PCA) case.
    • Food Safety News article on PCA.
    • Root Cause Analysis of the PCA Salmonella Outbreak.

Food Borne Illness Definitions

  • Foodborne Illness: A disease transmitted to people through food.
  • Foodborne Illness Outbreak:
    • When two or more people experience the same symptoms after consuming the same food.
    • An investigation is conducted by state and local authorities.
    • Laboratory analysis confirms the outbreak.

Three Types of Food Borne Illness Hazards (HACCP)

  1. Biological:
    • Bacteria, molds, viruses, parasites
  2. Chemical:
    • Unintentional Food Additives, Plant Toxins, Animal Toxins, Toxic Metals
  3. Physical:
    • Foreign materials like bone, wood, metal, glass.

Biological - Bacteria

  • Bacteria can be beneficial or harmful.
  • Pathogenic bacteria cause the majority of foodborne illnesses.
  • Three types of foodborne illnesses caused by bacteria:
    • Food Infections:
      • Majority of illnesses occur this way.
      • Ingestion of bacteria that grow in the intestines.
      • Example: Salmonella (most common cause of gastroenteritis), Listeria, Shigella
    • Food Intoxications:
      • Bacteria grow on food and produce toxins that are ingested and cause illness.
      • Examples: C. botulinum, C. perfringens, Staph aureus.
    • Toxin-Mediated Infection:
      • Bacteria enter the intestine and then produce the toxin, leading to illness.
      • Examples: E. coli, Vibrio, Campylobacter (second most common cause of gastroenteritis).

Biological - Virus

  • Transmitted via the fecal-oral route.
  • Norovirus:
    • Causes "stomach flu".
    • CDC indicates norovirus is linked to 58% of all foodborne illnesses in the U.S.
    • Found in raw or undercooked shellfish, salads, sandwiches.
    • Onset of illness: 1-2 hours.
    • Heating will kill this virus.
  • Hepatitis A:
    • Transmitted through contaminated water or food, not person to person.
    • Onset of illness: 10-50 days.

Bacterial - Mold

  • A fungus that lacks chlorophyll.
  • Produce mycotoxins that cause food intoxication.
  • Molds are typically visible.
  • Food with mold typically should not be eaten.
  • Many molds are good: cheeses, salami.

Biological - Parasites

  • Need a host to survive.
  • Trichinella spiralis:
    • Causes trichinosis from undercooked pork.
    • Thorough heating to 160°F will kill this parasite.
  • Protozoa:
    • Infect through contaminated water.
    • Giardia lamblia - most common parasitic infection
    • Toxoplasma gondii – causes issues in health compromised people. Pregnant women advised not to handle cat feces.

Chemical Hazard

  • Additives added unintentionally to food.
  • Examples: Cleaning solvents, pesticides, pollutants, seafood toxins.
  • Melamine in pet food:
    • An incident of intentional additive addition.
    • Melamine raised nitrogen levels in the pet food to falsely meet protein requirements.
    • Importance of knowing your supplier!
  • Fish toxins:
    • Ciguatera fish poisoning due to toxin-containing fish in tropical waters – barracuda consumption banned.
    • Histamines in fish due to bacterial growth on fish after being caught, causes tingling in the mouth.
    • Pufferfish or fugu – organs contain a toxin.

Physical Hazard

  • Typically added incidentally during processing:
    • Metal: wearing equipment in a food plant
    • Glass: packaging in food plants
    • Bone: brought in with ingredients
    • Staples: commonly used on ingredient packaging
    • Wood: pallets in food plants

How Does Food Become Unsafe?

  • Purchasing food from unsafe sources
  • Failing to cook food correctly
  • Inadequate cooking and improper holding time and temperatures
  • Using contaminated equipment
  • Practicing poor personal hygiene.

What are High Risk Foods?

  • Foods that contain:
    • High water content – high water activity = water available for bacterial growth
    • Low acid content (high pH)
    • High protein content
    • Sufficient oxygen availability
  • Examples of high-risk foods:
    • Meats and eggs – high in water and protein
    • Foods made with high-risk foods such as meatloaf, chicken salads, egg dishes

Temperature Danger Zone

  • Bacteria thrive within the Temperature Danger Zone; time and temperature play a critical role.
  • FDA Food Code:
    • Targeted to retailers.
    • Danger zone: between 41°F-135°F
  • USDA guidelines:
    • Targeted to consumers.
    • Danger zone: between 40°F – 140°F
  • Time Limit:
    • Continuous exposure to Danger Zone temperatures: maximum of 2 hours.
    • Limit cumulative exposure to Danger Zone temperatures: maximum of 4 hours.
    • Total time of 4 hours of exposure in danger zone

Food Processes to Provide Food Safety

  • Canning low acid foods (vegetables, meat, poultry)
    • High pressure used to achieve high temperatures of >240°F
    • Cook times yield commercial stability
  • Canning high acid foods (fruits, tomatoes, pickles)
    • Atmospheric pressure used to boil at 212°F (sea level)
    • Cook times yield commercial stability
  • Freezing foods
    • Stops bacterial growth, bacteria still survive
  • Dehydration
    • Limit water activity

HACCP – Hazard Analysis Critical Control Points

  • HACCP required for meat and poultry, juice, and seafood processing
  • FSMA requires a Food Safety Plan for other types of processing
  • HACCP origination
    • Developed by US Army Natick Research Laboratories and the Pillsbury company in the 1960’s
    • Developed for space food to provide a 100% assurance against foodborne illness in space for astronauts
  • HACCP based on 7 fundamental steps

7 HACCP Steps

  1. Assess and Identify Potential Hazards in the Food Process:
    • Biological, Chemical, Physical
  2. Identify Critical Control Points (CCPs):
    • CCP – points in the food process that MUST be controlled to ensure food safety
  3. Set quantifiable limits for the CCPs
    • For example, time and temperature specifications for canning food
  4. Monitor CCPs during the process
  5. Have a corrective action plan if the limits for the CCPs are not met
  6. Verify that the limits for the CCPs were met
  7. Document through record-keeping that the limits were verified