PPT 1 (SLIDE 42-82)

• Temperature lower than 41F

  • Bacteria cease to multiply but do not die
  • Freezing can cause cell wall damage
• Temperature higher than 135F

  • Bacteria die if heated for a sufficient time
  • Increased destruction with longer times and higher temperatures
• Controlling Growth - TIME

  • Under optimal conditions, some bacteria can double every 20 minutes.
  • The colder the storage temperature, the longer the potential shelflife.
  • Potentially hazardous foods should not remain in the danger zone (50-1400F) for more than 4 hours during the entire food handling process.
• Generation Time under Optimal Condition

  • Bacillus cereus = 28
  • Escherichia coli = 12.5
  • Staphylococcus aureus = 27-30
  • Mycobacterium tuberculosis = 792-932
• Based on oxygen requirements;

  • Aerobic - Need oxygen to grow
  • Anaerobic - Can grow only if oxygen is absent
  • Facultative - Can grow with or without oxygen.
• Moisture – Water Activity

  • Water Activity (Aw) is the measure of “free” water available to the microorganism for growth
• Water Activity

  • Aw is affected by the presence of solutes (sugars and salts)
  • Lowering aw will reduce the ability for microorganisms to grow
• Moisture in a food system that is available for microbial growth and chemical reactions – the relative humidity of a food.
• Water Activity - Humidity

  • 0.98 - 0.995 most foods.
  • 0.85 - .995 for disease causing organism's range .
  • 0.60 - .995 for spoilage organisms
• “Hurdles Concept”

  • Predictive microbiology the study of interactive effects of factors effecting microbial growth

  1. Additive
  2. Synergistic
  3. Antagonistic
• Ingredients

  • Have good specifications and control of incoming ingredients
• Process

  • Have an adequate thermal process to destroy microorganisms
  • Have an adequate packaging system to protect your product
• After Processing

  • Have control of distribution and a system for tracking and recalling
  • Provide necessary information for consumers (labeling)
• Farm to Fork Food Safety and Quality Programs

  • HACCP, GMPs, Sanitation
• FOOD INDUSTRY INTERVENTION

  1. Ingredients
  2. Process
  3. After Processing
  4. Farm to Fork Food Safety and Quality Programs
• INGREDIENT CONTROL

  
  

  Specifications for ingredient make-up, quality, physical and microbial contaminant levels

  • Letter of guarantee
  • Certificate of analysis
• Thermal Processing

  • Cooking
  • Pasteurization
  • Commercial sterility (shelf-stable) processes
• Package Integrity

  • Measurements are made to insure the package is of good sanitary quality and can maintain a hermetic seal.
• General Roles of Microorganisms

  • Commensal - ubiquitous, harmless or beneficial
  • Spoilage - Cause food to become inedible due to changes in color, flavor, odor, appearance or texture.
  • Beneficial - Used as an aid in producing desirable characteristics in food.
  • Pathogens - Cause foodborne illness.
• Common Food-Borne Pathogens: Bacteria

  1. E. coli 0157: H7
  2. Salmonella spp.
  3. S. aureus
  4. Listeria monocytogenes
  5. Campylobacter jejuni
  6. Shigella spp.
• Common Food-Borne Pathogens: Viruses

  1. Norovirus
  2. Rotovirus
  3. Hepatitis A
• Common Food-Borne Pathogens: Parasites

  1. Cryptosporidium parvum
  2. Giardia lamblia
  3. Cyclospora
• Infection

  • Microorganisms are ingested and then cause illness
• Intoxication

  • Toxins are produced by the pathogen, usually in the food. When food is consumed, illness occurs.
• 80-90% of food borne illnesses

  • Campylobacter
  • Salmonella
  • Clostridium perfringens
  • Staphylococcus aureus
• Bacterial Pathogens of concern

  • E. coli 0157:H7
  • Salmonella
  • Listeria
  • Campylobacter
  • Staphylococcus aureus
  • Clostridium botulinum
• E. COLI O157:H7

  • Hemorrhagic colitis
  • Cause: infection
  • Incubation: 2-4 days
  • Symptoms: diarrhea (blood), HUS, TPP
  • Contaminant: milk, meat, fruits, vegetables, water
• SALMONELLA

  • Salmonellosis
  • >2000 strains, 10 = foodborne illness
  • Cause: infection
  • Incubation: 6-48 hours
  • Symptoms: nausea, fever, diarrhea, arthritis
  • Contaminant: milk, meat, eggs
• Listeria monocytogenes

  • Listeriosis
  • Cause: infection
  • Incubation: 2 days - 3 weeks
  • Symptoms: vomiting, diarrhea
  • Contaminant: vegetables, milk, cheese, meat, seafood
• CAMPYLOBACTER JEJUNI

  • Campylobacteriosis
  • Cause: infection
  • Incubation: 2 - 5 days
  • Symptoms: nausea, fever, diarrhea (blood)
  • Contaminant: milk, meat, water
• STAPHYLOCOCCUS AUREUS

  • Staphyloenterotoxicosis
  • Cause: intoxication (1 mg toxin = 100,000 cfu/g)
  • Incubation: 1-6 hours
  • Symptoms: nausea, fever, diarrhea
  • Contaminant: milk, meat, eggs
• CLOSTRIDIUM BOTULINUM

  • Botulism
  • Cause: intoxication (spores - neurotoxin)
  • Incubation: 18 - 36 hours
  • Symptoms: weakness, vertigo
  • Contaminant: pH >4.6, low oxygen foods
• Prevention of Food borne Illnesses

  1. Cook
  2. Avoid cross contamination
  3. Chill foods
  4. Cleaning
  5. Personal hygiene
• Spoilage Organisms: Bacteria

  • Erwinia, Pseudomonas, Flavobacteria, Enterobacter spp.
  • Lactic Acid Bacteria
• Spoilage Organism: Fungal

  • Penicillium, Aspergillus, Fusarium, and Candida