1. Microorganisms
C Microbiology

2. Microbiology Microorganisms are everywhere.
Microbiology is the study of microorganisms—living organisms too small to be seen by the naked eye without magnification.
C Microbiology

3. Three Roles of Microorganisms
Pathogens -- cause foodborne illness.
Spoilers -- cause food to spoil and decrease its shelf-life.
Beneficial -- used for food fermentation and are naturally present in and on the body.
C Microbiology

4. Contaminated Food Microorganisms can contaminate any food:
naturally or
through improper food handling
Contaminated food can cause foodborne illness or food spoilage.
Measures must be implemented to control for:
Food safety – preventing foodborne illness and
Food quality – maximizing shelf-life
C Microbiology

5. Pathogens Foodborne illness Foodborne illness outbreak
An illness caused by eating contaminated foods or beverages. 
Foodborne illness outbreak
the occurrence of two or more cases of a similar illness resulting from eating a common food.
Each year there are:
76 million cases of foodborne illness
323,914 hospitalizations
5,194 deaths
C Microbiology

6. Spoilers
Cause the deterioration of food, such as sour milk or lunch meat turning slimy.
Eating spoiled food does not usually cause illness.
Food spoils because of microbial growth or enzymatic activity.
C Microbiology

7. Beneficial
Beneficial microorganisms are not contaminants – they are naturally present or are intentionally added to foods.
Primary purposes:
Health benefits – naturally present on skin and in the intestinal tract.
New food products – use for food fermentation to create new products.
Yogurt
Sour dough
culture
C Microbiology

8. Five Major Groups of Microorganisms
Bacteria
Viruses
Parasites
Mold
Yeast
PHOTOGRAPH CREDITS:
Ralph Van Dyke Jr.
The Des Moines University Osteopathic Medical Center
Des Moines, Iowa USA
This strain of Bacillus cereus was isolated from a sample of gasoline-contaminated soil and cultured on blood agar during the Summer Microbiology Practicum at the Des Moines University, Iowa. Spores were present after 3 days, however, this picture was taken 1 week after culture. Endospores are extremely hardy bacterial structures that contain the organism genome. Endospores remain viable through many extreme conditions, such as common cooking techniques. Endospores can be destroyed by proper pressure canning or pressure cooking. B. cereus can cause severe food poisoning with a short incubation period. A common source can be fried rice made from unrefrigerated cooked rice. Short incubation B. cereus food poisoning can be mistaken for staphylococcal food poisoning. This picture allows students to see spores utilizing a simple, reliable method of staining.
C Microbiology

9. Bacteria Basics Invisible to the naked eye.
Pathogens, spoilers, and beneficial.
Grow in food.
Some produce spores.
Some produce toxins.
Not necessarily destroyed by freezing or cooking.
Bacillus cereus
C Microbiology

10. Virus Basics Invisible to the naked eye.
Pathogens -- not spoilers or beneficial.
Do not grow in food; use food as a vehicle to get from one person to another
Can contaminate any food
Cause most foodborne illnesses in the U.S.
Usually destroyed by cooking but not freezing.
Norovirus
C Microbiology

11. Parasite Basics Some are visible to the naked eye
Pathogens – not spoilers or beneficial.
Do not grow in food
Found naturally in many animals
pigs
cats
rodents, and
Seafood
Destroyed by proper freezing and cooking.
Anisakis simplex
C Microbiology

12. Mold Basics Visible to the naked eye.
While most spoil food, some are pathogenic and some beneficial.
Some form toxins that can cause illness.
Grow in a wide range of foods – high acid, low moisture.
Requires air to grow
Freezing does not destroy.
C Microbiology

13. Yeast Basics Visible to the naked eye.
Spoilers and beneficial but not pathogenic.
Grow in a wide range of foods – high acid, low moisture.
Produce a smell, bubbling, or a taste of alcohol when food spoils
Easily destroyed by proper processing.
C Microbiology