1. Food safety

2. INTOXICATION VS INFECTION
Food Intoxication- toxins/ toxicants responsible
Produced in foods as by-products of microorganisms, plants or animals
Cause disease upon ingestion
Food Infection- multiplication of pathogenic Microorganisms responsible
Viable microorganisms in the food at the time of consumption-> grow in the host- cause illness.

3. microorganisms We can find them everywhere
Microorganisms cause a great deal of food spoilage throughout the world
This has major economic consequences and as well as loss of potential sources of nutrients, since the food typically is discarded.

4. microorganisms Examples of microorganisms: Bacteria, mold and yeast
Viruses can be agents of food borne disease but
VIRUSES DO NOT CAUSE FOOD SPOILAGE, NOR DO THEY PRODUCE FERMENTED FOODS

5. MICROORGANISMS The Good--- The BAD--- The ugly---
Used in food processing (cheese, yogurt, olives)
The BAD---
Can cause food spoilage
Food preservation, packaging and storage technology kills or delays metabolic activities of MO
The ugly---
MO that can cause foodborne disease
Food processing, packaging and storage techniques are designed to kill these MO or prevent their growth

6. Bacteria, yeast, molds
Bacteria- unicellular organism-1 micron or less in length
Gram staining- classify bacteria based on whether the bacteria retain crystal violet in their cell membrane
Gram positive ( violet/blue)- thick cell wall, with no outer membrane
Gram negative( pink) – thin cell wall and have an outer membrane
Rods (long and narrow)

7. Bacteria, yeast, molds Bacteria- fast growth
Generation time fir 1 cell division cycle
Eg) if 7 min,then in 3.5 hrs (210 min), one cell would multiply to 2 30= 1 billion cells!
Vegetative cells (active) or spores (dormant)
Cocci (circular shape) and rods (long and narrow)

8. Bacteria Vegetative cells ( active) or spores ( dormant)
Clostridium botulinum
Vegetative cells ( active) or spores ( dormant)
Cocci (circular shape) and rods (long and narrow)

9. Yeasts Yeasts- slower growth but more toleratnt
Tolerant lower pH or water activity
Reproduced by budding

10. Molds Molds- even more tolerant of low pH and water activity
Grow by network of hairlike fibres (mycelia)  spores
Spores
mycelia

11. Bacteria & mold Spores Spores- dormant form
Very resistent to various conditions
Germinate under favorable conditions -> active vegetative cells
Notorious example: clostridium botulinum
Spores are very heat resistant
Germinate-> Toxin-> Botulism (pathogenic)
Spores do not change flavors
Stomach acid will not allow spores to release
BoTox- botulism toxin

12. Classification of microrganisms by Oxygen and Temperature requirements for growth
Oxygen requirements:
Faculative anaerobe- in presence / absence of oxygen
Bacteria, yeasts
Small amount of oxygen ( not Mold)
Mold may only grow on top in jar
Anaerobic- only in the absence of oxygen
Bacteria only
Aerobic- only in presence of oxygen
Bacteria, yeast, molds

13. Classification of microorganisms
temperature requirements
min max optimum
Psychrophiles o C
Psychrotrophs 0 to cause food spoilage in frig (listeria—deli meats)
Mesophiles pathogens- cause disease/ grow in danger zone
Thermophiles spores of c.botulism
Spoilage of refrigerated foods- psychrotrophs
Many disease causing bacteria are mesophiles

14. What contributes to microbial growth?

15. F= Food F=Food (Carbohydrates, Proteins and Fats)
A= Acidity ( pH higher than 4.6)
T= Temperature ( outside danger zone 41o F to 135o F)
( keep hot foods hot, cold foods cold)
T= Time (longer exposure = greater MO growth)
O= oxygen (greater exposure faster MO growth)
M= Moisture (water activity)

16. Microorganisms and Foodborne Disease
Foodborne Illness Outbreaks | Food Safety News

17. FACTS 5200 PEOPLE DIE EVERY YEAR FROM FOODBORNE ILLNESS
76 million cases of foodborne disease occur each year in the US
cdc

18. Foodborne disease etiology (causes)
Parasitic
Cryptosporidium (water)
Anisakiasis (fish)
Acquired from consumption of infested food/ water
Plant
amanita mushrooms, taro leaves, green potatoes, etc
Animal
Poisonous animals
Shellfish containing paralytic toxins, puffer fish, etc
Chemical
Tin in corrosive metal cans, cleaning and sanitizing agents, etc
Microbiology= food/Waterborne Diseases (FBD)

19. Parasitic Cryptosporidium (water) Anisakiasis (fish)
Acquired from consumption of infested food/ water
Parasites such as Trichinella (pork)

20. Plant amanita mushrooms, taro leaves, green potatoes,…
FBD example- solanine from green potatoes inhibit the action of enzyme ( cholinesterase) and interfers with nerve transmissions and impulses

21. Potatoes cont. Low levels (potato skin= 2.13mg/ 100g fresh weight)
“green” potatoes ( sunlight)-> mg/ 100 g fresh weight
Solanine is insoluble in water
Lower the concentration by simply peeling potato
Not destroyed by heat ( cooking)
At 2-8 mg/kg baking weight humans display drowsiness, difficulty breathing, increased sensory sensitivity
Toxic ( LD50= 42mg/kg)
LD =lethal dose
But relatively low hazard /risk unless -> green potatoes

22. Animal Poisonous animals
Shellfish containing paralytic toxins, puffer fish, etc

23. Seafood toxins Saxitoxin- paralytic shellfish poisoning (psp)
Neurotoxin in microscopic plankton (dinoflagellates)
May bloom under certain conditions (red tide)
Found in shell fish ( muscles, clams, oysters)
‘filtering’ organisms- absorb toxins from water and concentrate it in their tissues
Both on east and west coasts of US
Muscular and nerve paralysis
Toxicity LD 5 mg/kg body wt (LD50 )
Hazzard: know source of seafood, heed red tide signs

24. Chemical
Tin in corrosive metal cans, cleaning and sanitizing agents, etc

25. Reasons why only some FBD are reported?
Lack of reporting- Only 1-4 % are reported
Mistakenly diagnosed
Mild cases blamed on 24 hour flu, a virus, overeating
Doctors fail to report to local health dept due to lack of evidence/ research available 5

26. Who is most at risk? Very old Very young Immunocompromised
Expectant mothers ( pregnant)

27. Mold toxins (mycotoxins)- produced by molds
Ergotism-(claviceps purpurea)= st Anthony’s fire
Rye and other cereal grains
Chemical ergot
Similar to LSD ( hallucinogens, insanity)
peanuts, corn, wheat, rice, cottonseed, nuts, milk, eggs, cheese
Highly toxic and potentially carcinogenic
Contains vaso constricting alkaloids (precursors for LSD 25)
Believed to be part of the salem witch hunt hysteria (1692)
Mouldy rye bread … Science, 1976 v. 192

28. Mycotoxins- produced by molds
Aflatoxins (aspergilus flavus)
Peanuts, corn, wheat, rice, cotton seed, nuts, milk, eggs, cheese
Highly toxic and potently carcinogenic
liver cancer

29. Examples of food intoxication Clostridium botulinum E coli
Food infection
Salmonella
Listeria
Virus
Hepatitus a
norwalk

30. haccp

31. Factors in fbd Prep food too far in advance and store improperly
Insufficient cooking/ reheating
Inadequate cooling
Cross contamination
**most pathogenic MO do not alter color, aroma, flavor, or texture of foods

33. Poster project
Choose one pathogen and create an illustrated poster with detailed information to present to the class.
Include:
Scientific name
Picture or drawing of pathogen
Common name
Classification
Food sources
Symptoms/ results
Possible Prevention/ elimination methods or steps
Other information