This document defines microorganisms and discusses their role in food. Microorganisms, including bacteria, parasites, viruses, yeasts and molds, are found everywhere in the environment including soil, water, plants, equipment, food handlers and animals. They can be pathogenic and cause illness, cause spoilage by making food unacceptable, or be used in fermentation to produce desired food products. Common foodborne pathogens discussed include E. coli, Salmonella, Staphylococcus, Listeria, Campylobacter, Shigella, norovirus, rotavirus, cryptosporidium and giardia. Illnesses can occur through infection or intoxication. Spoilage microorganisms like Pseudomonas

1. FOOD MICROBIOLOGY

2. Definition
⮚Microorganisms: Organisms such as bacteria,
parasites, viruses, yeasts, and molds.
–Usually too small to be seen by the naked eye.

3. WHERE ARE MICROORGANISMS?
⮚ Soil & Water
⮚ Plants/Products
⮚ Utensils/Equipment
⮚ •Gastrointestinal
Tract
⮚ Food Handlers
⮚ Animal Feeds
⮚ Animal Hides
⮚ Air & Dust

4. MICRORGANISMS IN FOOD
Microorganisms are important in
many different ways:
⮚Pathogenic, or disease causing, microorganisms can cause
illness
⮚Spoilage microorganisms cause a food to smell, taste, and look
unacceptable
⮚Fermentation microorganisms produce a desired food product
⮚Other microorganisms do nothing in foods

5. MICROORGANISMS AND OUR
FOOD

6. GENERAL ROLE OF MICRO-
ORGANISMS
⮚ Commensal
▪ Ubiquitous
▪ harmless or beneficial
⮚ Spoilage
▪ Cause food to become inedible due to changes in color,
flavor, odor, appearance or texture.
▪ Grow to high levels and break down food components
▪ Commensal organisms that have reached high populations
(105-107 CFU/g)
▪ Different products have different spoilage flora

7. GENERAL CHARACTERISTICS OF
MICROORGANISMS
⮚ Beneficial
▪ Used as an aid in producing
desirable characteristics in
food
⮚ Pathogens
▪ Cause foodborne illness
▪ Microorganisms that are
usually associated with the
presence of pathogens are
called “Indicators”. Most E coli
do not cause illness

8. FOOD SAFETY VS. FOOD
QUALITY
⮚ Food safety controls HAZARDS to the consumer.
– A foodborne hazard is a biological, chemical, or physical property
that may cause a food to be unsafe for human consumption
⮚ Food quality controls deterioration of food to an unacceptable state

9. COMMON FOODBRONE (FOOD
POISING) PATHOGENS
BACTERIA VIRUSES PARASITES
⮚ E. coli 0157:H7 Norovirus Cryptosporidium parvum
⮚ Salmonella spp. Rotovirus Giardia lamblia
⮚ Staphyloccus aureus Hepatitis A Cyclospora
⮚ Listeria
monocytogenes
⮚ Campylobacter jejuni
⮚ Shigella spp.

10. ILLNESS MECHANISM
⮚ 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.
–Even if microorganisms
are killed, toxin can
still remain the food.

11. Prevention of Foodborne
Illnesses
⮚ Cook
⮚ Avoid Cross-Contamination
⮚ Personal Hygiene
⮚ Cleaning
⮚ Chill Foods
⮚ In addition, food handlers should not
work with food if they have a boil,
open sores or feel sick themselves.

12. SPOILAGE ORGANISMS
⮚ Bacterial (hundreds of
bacteria cause spoilage)
–Erwinia, Pseudomonas,
Flavobacteria, Enterobacter.
–Lactic acid bacteria
⮚ Fungal
–Penicillium, Aspergillus,
Fusarium, and Candida
65

13. MICROORGANISMS PLAY AN
IMPORTANT ROLE IN FOOD
The microorganisms that cause
food spoilage and also find the
maximum exploitation in
production of food and food
products are mainly bacteria,
molds and yeasts.

14. CONCLUSION
⮚ Food Microbiology is huge area
⮚ FAT TOM
⮚ Pathogens – Food Safety
⮚ Spoilage microorganisms – costly

15. PRESENTED BY: GROUP IX
GROUP MEMBERS: UNAIZA BROHI,
FAREEHA MANSOOR, SYEDA SAFIA,
SAMREEN AKRAM