1. Microbial Hazards
 2. Physical Hazards
 3. HAACP
 
 

Microbial Changes

• Microorganism: Small organisms invisible to the naked eye
• Some cause spoilage while others cause food poisoning and infections.
• Note: Some of these organisms are actually used to make food products (see fermentations).
• Microbial growth is dependent on several factors:
• pH: Growth best near neutrality
• Aw: Growth best when there is more free water
• Temperature: Most organisms grow best at room temperature (75 F or 25 C)

• Psychrophiles: Grow at refrigerator temperatures (40 F or 4 C)
• Mesophiles: Grow best at body temperature (98 F or 37 C)
• Thermophiles: Can grow at relatively high temperatures (160 F or 71 C)

• Presence or absence of oxygen
• Aerobes: Require oxygen
• Anaerobes: Grow only in the absence of oxygen
• Facultative anaerobes: Can grow in the presence or absence of oxygen

Bacteria

• Definition: A variety of unicelluar organisms that grow under diverse conditions.
• Considered structurally "primitive" compared to other organisms; prokaryotic.
• Can grow very fast at optimum conditions
• Can grow under a wide variety of different conditions:

• Temperature
• Oxygen concentration
• pH:
• Aw: Halophiles - grow in high concentrations of NaCl
• Some cause food spoilage while others can cause illnesses

• Classes of illnesses:
•  Food infection
• Requires ingestion of bacteria
• Symptoms typically 12-24 hrs after ingestion
• Typically not fatal but can be for elderly, children and the immune suppressed.
• Food Poisoning
• Toxin left in the food (does not require ingestion of bacteria)
• Symptoms typically 6-12 hrs after ingestion
• Some can be very fatal while others can be for elderly, children and the immune suppressed.

Examples of Food Infections

• Escherichia coli (0157:H7)
• Many reported cases in undercooked meat products. Also reported in un-pastuerized apple juice.
• Causes severe diarrhea & abdominal cramps
• Typically only fatal for elderly, children and the immune suppressed.
 
 
        E. coli
 
• Salmonella
• Reported cases primarily with poultry & egg products
• Causes severe diarrhea, abdominal cramps & vomiting
• Typically only fatal for elderly, children and the immune suppressed
 
 
        Salmonella
 
 
• Listeria
• Organism ubiquitous in nature
• Reported cases in many products, however typically in meat and dairy
• Organism can grow refrigerator temperatures
• Causes a wide variety of symptoms including vomiting, diarrhea & fever
• Can be fatal, especially for pregnant women elderly, children and the immune suppressed
 
 
        Listeria cases
 

• Clostridium perfringens
• Organism ubiquitous in nature (soil)
• Sporeformer and anaerobic
• Reported cases in meats and gravies; prevent by proper cooling of foods
• Causes diarrhea, abdominal pain and headache
• Typically not fatal except for elderly, children and the immune suppressed
 
 
        Clostridium perfringens
 
• Clostridium botulinum
• Organism ubiquitous in nature (soil)
• Sporeformer and anaerobic
• Reported cases in canned foods with pH > 4.5; Also reported in fish and causing death in infants consuming honey
• Neurotoxin that causes fatal muscle paralysis
• Prevention: Cook suspected foods to boiling (212 F or 100 C) for several minutes before eating
        
 
• Staphylococcus aureus
• Organism ubiquitous and halophilic. Note in hair and nasal passages
• Reported in meats, salads, and dairy products
• Heat stable toxin that causes severe abdominal cramps, diarrhea and vomiting
• Typically not fatal except for elderly, children and immune suppressed
• Prevention: 1) proper food handling; 2) refrigeration
 
 
        Staphylococcus aureus
 

• Yeasts
• Larger in size than bacteria & eukaryotic
• Typically can grow at lower Aw & pH than bacteria
• Typically spoilage only (no sickness)
• Very heat sensitive
 
 
        Yeast
 
• Molds
• Very advanced physiologically and can be multi-cellular
• Can form spores (not very heat resistant) and typically aerobic
• Grow at very low Aw and pH conditions
• Can cause spoilage or disease
• Can cause food poisoning by toxins (mycotoxins)
• Example of mold disease is Aflatoxin
• Caused by mold Aspergillus flavus (and some others)
• Found in cereal grains (corn) and peanuts
• Immediately fatal in large doses and carcinogenic at low doses
• Prevent by the use of "mold inhibititors" (phosphates & propionates)
 
 
    Aspergillus flavus
 
• Roundworm
• Trichinella spiralis causes trichinosis
• In the past transmitted primarily through pork (consuming "unprocessed" feed); Can also be transmitted through other animals.
• Worm migrates into muscle causing high fever and swelling. Can be fatal w/o treatment
• Control: 1) heat processing of feed; 2) cook suspected food to 58.3 C or 137 F internal temperature (no pink color)
 
 
        Trichinella spiralis
 
 
• Virus
• Specific microbial "parasites" that can cause a variety of diseases
• Diseases in food from enteric viruses include:
• Hepatitis A: Liver disease caused by virus through poor hygiene. Rarely fatal, but no real treatment.
• Norwalk Virus: Causes vomiting, diarrhea & abdominal pain. Rarely fatal.
• Prevent these diseases by proper food handling practices.

• Personnel Standards
• Hand washing
• Persons should be healthy
• Hair covering
• Proper clothing
• Ingredient Control
• Meat and animal products
• Spices tend to be susceptible due to processing procedures
• Check ingredient sources for good handling practices
• Plant Cleanliness
• Clean: Remove hiding places & food from microorganisms, and disease carrying organisms
• Sanitize: Kill most or all microorganisms on surfaces

Bovine Spongiform Encephalopathy (BSE)

• Also called mad cow disease
• Caused by self-replicating protein called a "prion"
•  Source of prion believed to be ruminant feed containing brain or spinal material.
• Similar disease found in other animals such as sheep and mink.
• In humans appears as Creutzfield-Jacob Disease (CJD), a degenerative brain disease.
• In 1996 10 cases found in young people from Britain.
• Due to their youth they suspected that they contracted the disease from cows with BSE.
• Not considered a problem in the U.S. because:
• U.S. banned ruminant-ruminant feeding in 1997.
• U.S. not importing animals or beef from countries having BSE in their herds.
• How to tell if your beef has Mad Cow Disease (humor)