This document provides an introduction to food microbiology presented by Dr. Greeshma P.V. of St. Mary's College. It discusses the scope of food microbiology including microorganisms' role in food spoilage, preservation, safety, and fermentation. It also describes various microorganisms important in food microbiology such as molds, yeasts, and bacteria. Additionally, it examines factors affecting microbial growth in food and various methods for preserving food, as well as the microbiology of food commodities and foodborne illness.

1. An Introduction To Food
Microbiology
Dr. Greeshma P.V
Assistant Professor
Department of Microbiology
St. Mary’s College, Thrissur

2. An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College
Scope of food microbiology
Micro-organisms and food- can cause spoilage, food borne
illness, beneficial way helps in food fermentation
 Food spoilage/ preservation- food preservation can be done
using preservatives to reduce the spoilage.
 Food safety- Biological contaminants are the major cause of
food illness.
 Fermentation.
 Microbiological quality assurance.

3. Microorganisms important in food
Microbiology
Molds- General characteristics of molds (Morphological,
physiological and cultural characteristics). Classification and
identification of molds- Mucor, Rhizopus, Penicillium, Geotrichum,
Neurospora..
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

4. Yeasts-General characteristics of yeasts (Morphological, physiological
and cultural characteristics). Classification and identification of yeasts,
Yeasts of industrial importance.
Bacteria- Morphological, physiological and cultural characteristics,
Genera of bacteria important in food bacteriology.-Acetobacter,
Arthrobacter, Bacillus, Clostridium, Enterobacter, Lactobacillus...
Group of bacteria important in bacteriology.
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

5. An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

6. Microorganisms and food materials
Diversity of habitat
 Microorganisms in the atmosphere- Airborne bacteria, fungi
 Microorganisms of soil
 Microorganisms of water
 Microbes of plants
 Microbes of animal origin- Skin, Nose, Throat
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

7. Factors affecting the growth and survival of
microbes in food
Microbial growth
Intrinsic factors- Nutrient contents, pH and buffering capacity,
Redoxpotential, antimicrobial barriers and constituents, water
activity
Extrinsic factors – Relative humidity, temperature, gaseous
atmosphere.
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

8. The microbiology of food preservation
Heat processing- Pasteurization and appertization, quantifying the
thermal death of microbes,aseptoc packaging
 Irradiation- Microwave radiation, UV radiation, Ionizing radiation
 High pressure processing- Pascalization
 Low- temperature storage- chilling and Freezing
Chemical preservatives-Organic acids and esters, Nitrite, Sulfur
dioxide, Natural food preservatives.
Modification of atmosphere.
Control of water activity.
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

9. Microbiology of primary food commodities
What is spoilage
Milk- Composition, micro flora of raw milk, heat treatment of milk,
milk products.
Meat- Structure and composition, spoilage of fresh meat
Fish- Composition, primary processing, spoilage
Plant products- Cereals, Pulses, Nuts and oil seeds, Fruits and its
products, Vegetables and its products.
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

10. An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

11. Food microbiology and public health
Food hazards
Significance of food borne disease
Incidence of food borne illness
Risk factors associated with food borne illness
The site of food borne illness. The alimentary tract- Its
function and micro flora.
The pathogenesis of diarrheal disease
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

12. Bacterial agents of food borne illness
Brucella, Bacillus cereus and other species, Campylobacter,
Closttridium botulinum, Clostridium perfringens, Escherichia coli,
Listeria monocytogenes, Salmonella, Shigella, Staphylococcus
aureus, Vibrio, Yersinia enterocolitica- Introduction, its origin,
pathogenesis, isolation and identification, association with foods.
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

13. An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

14. An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

15. Non-bacterial agents of food borne illness
Helminths and Nematodes- Platyhelminths (Liver flukes and
Tapeworms), Roundworms
Protozoa- Giardia lamblia, Entamoeba histolitica, Sporozoid
protozoa
Toxigenic algae- Dinoflagellate toxins, Cyanobacterial toxins
Toxigenic fungi- Mycotoxins of Aspergillus, Mycotoxins of
penicillium, Mycotoxins of Fusarium, Mycotoxins of other fungi
Food borne viruses- Polio, Hepatitis A and E, Gastroenteritis viruses
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

16. An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

17. An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

18. Fermented and microbial foods
Yeasts
Lactic acid Bacteria
Activities of lactic acid bacteria in foods- Antimicrobial activity
of lactic acid bacteria, Health promotoing effects, malo-lactic
fermentation.
Fermented milks- Yoghurt, Other fermented milks, Cheese
Fermented vegetables- Sauerkraut, olives, cucumbers
Fermented meats
Fermented fish
Beer
Vinegar
Mould fermentations
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

19. An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

20. Methods for the microbiological
examination of foods
Indicator organisms
Direct examination
Cultural techniques
Enumeration methods- Plate counts, MPN count,
Alternative methods-Dye-reduction test, electrical methods, ATP
determination
Rapid methods for the detection of specific organisams and
toxins- Immunological methods, DNA/RNA methodology.
An introduction to food microbiology, Dr. Greeshma P.V, St.Mary’s College

21. THANK YOU