Food microbiology is a branch of applied microbiology and the scope of food microbiology is expanding rapidly to protect food from microbial spoilage and provide safe, nutritious food to consumers. We now live in a period of world- wide food crisis, a food saved is a food produced. The book embodies twenty chapters covering the types
and sources of microorganisms in food, factors influencing microbial growth in foods; Preservation of food by high temperature, low temperature, dehydration, osmotic pressure, irradiation, high pressure processing, chemical preservatives, food storage and packaging; Food safety and quality management, fermented food products, dairy microbiology, microbial foods and chemicals, mushroom cultivation, and microbial enzymes. Bacterial food poisoning, mycotoxin and impact of genetically modified foods with descriptive and objective questions. In addition, procedures for fifteen practical experiments in food and dairy microbiology and glossary are included.
The overall objective of this book on & Food Microbiology is to bring together information on different areas of food microbiology in a single source.
N. Ramanathan
About the Author
Dr. N. Ramanathan, obtained his masters degree and Ph.D in Microbiology from Annamalai University and served as Professor and Head, Department of Microbiology, Annamalai University, Tamil Nadu (2012-2015). He has around 27 years of UG and PG Teaching and Research experience. He has published more than 40 research papers in reputed journals and guided 40 M.Phil and 9 Ph.D candidates. He has attended 50 International and National conferences and delivered special lectures. He has organized two National seminars on Applied Microbiology. He was conferred the ‘Best teacher’ award by the university. He is life member of Indian Association of Applied Microbiologists and as Principal investigator conducted UGC major research projects. He is the author of text books on Principles of Microbiology, Environmental Microbiology, Objective Agricultural Microbiology and Objective Medical Microbiology. He served as Chairman and member of various academic bodies in several reputed universities and colleges.
Preface
The biodiversity of foods-cereals, pulses, oilseeds, spices, fruits and vegetables is varied and high in India, where we have varied agro-climatic regions from Kashmir to Kanyakumari. India is one of the World’s major food producers and total food production in India is likely to double in next ten years.
Green revolution (crop production), White revolution (milk production) and Blue revolution (fish production)
were responsible for our country to meet the national requirements in food production. Biotechnological application in Agriculture and Animal Husbandry are going to play a pivotal role in further enhancing the food production.
Man has exhibited much thought and foresight in cultivating a variety of grains, fruits, vegetables, nuts and oilseeds and in rearing birds and animals for use as food. Food provides a rich habitat for microorganisms, as most foods contain an abundance of nutrients such as carbohydrates, proteins and lipids, vitamins and minerals.
Microbial association with foods can be of desirable or undesirable nature in relation to the food product. However, foods are prone to microbial contaminants, which are known for their undesirable changes in foods-food spoilage and food poisoning. Although chemical changes and microbial growth usually mean food spoilage, in some cases, fermentation is desirable and microorganisms are actually added to foods. For example, in the production of fermented foods such as wine, bread, yoghurt, fish sauce, pickles, sausages, soya sauce etc.
Microorganisms themselves are used as food (SCP, mushrooms) and their chemical products (organic acids, enzymes) are used in food processing. The plant, animal and microbial foods are now genetically modified to improve their qualities.
Contamination, preservation and spoilage of cereals, sugars, fruits and vegetables, meat, sea foods, eggs and poultry, milk and milk products, canned foods; Bacterial food poisoning, mycotoxin and impact of genetically modified foods with descriptive and objective questions.
Contents
1 Basic Principles of Food Microbiology
- Importance of Food Microbiology
- Types of Microorgnisms in Food Disease Causing Bacteria/Food Pathogens
- Primary Sources of Microbes Found in Food
- Factors Influencing Microbial Growth in Foods
- Yeasts
- Protozoa
- Soil and water
- Plant and plant products
- Food equipments and utensils
- Intestinal tract of man and animals
- Food handlers
- Animal feeds and hides.
- Air and dust
- pH
- Moisture
- O-R potential (Oxidation Reduction Potential)
- Nutrient Content of Foods
- Inhibitory substances in foods
- Biological structure
2 Food Preservation
2.1 High Temperature Terms used in high temperature food preservation High Temperature Methods
2.2 Low Temperature
Advantages of low termperature
Effect of low temperaturer on microbial activity. Low Temperature Methods
Methods of Freezing
2.3 Dehydration
Drying and Dehydration
Purpose of Drying
2.4 Osmotic Pressure
2.5 Irradiation
Methods of Irridation
Food irradation procedure
Advantages and Disadvantages
2.6 High Pressure Processing of Foods.
2.7 Chemical Preservatives Mode of Action
2.8 Food Storage and Packaging
Controlled Atmosphere Storage
Modified atmosphere packaging (MAP)
Aseptic packaging
Food package
3 Food Safety and Quality Management
3.1 Food Safety Biological Hazards in Foods
3.2 HACCP Principles
3.3 Food Standards
3.4 Food Safety in India
4 Conduct Hazard Analysis
5 Identify Critical Control Point
5.1 Establish Critical Limits for Preventive Measures.
5.2 Establish CCP Monitoring System
5.3 Establish Corrective Action for Deviation From CCP
5.4 Establish Verification Procedure
5.5 Establish Record Keeping Procedure
5.6 Highlights of the Food Safety and Standard Act, 2006
6 Microbial Foods (SCP) and FOOD Chemicals
Single Cell Protein (SCP) and Protein Deficiency
6.1 Microbial Groups and Substrates
6.2 Selection of Organism for SCP
6.3 Spirulina SCP
Species of Spirulina
Mass Production of Spirulina
Growth Requirements for Masscultivation Uses of Spirulina
6.4 Yeast SCP Production
Bacterial SCP Production Mycoprotein Production
6.5 Single Cell Oil (SCO)
6.6 Food Chemicals
Mushrooms Cultivation
Edible Mushrooms
Advantages of Mushrooms
Nutritive Value
Mushroom Cultivation in India
7.1 Button Mushroom Cultivation – Agaricus bisporus
Composition of Compost
7.2 Shiitake Mushrooms- Lentinus edodes
7.3 Cultivation of Paddy Straw Mushroom- Volvariella volvacea
7.4 Cultivation of Oyster Mushroom- Pleurotus spp
Comparison of Common Edible Mushroom Cultivation
8 Microbial Enzymes Pharmaceuticals
8.1 Amylases
Industrial Production of Alpha Amylase
Applications
8.2 Proteases
8.3 Glucose Enzymes
8.4 Pectic Enzymes
8.5 Applications of Enzymes.
8.6 Applications of Immobilized Enzymes Questions
9 Contamination and Spoilage of Foods. Classification of Food by ease of spoilage.
10 Contamination, Preservation and Spoilage of Cereals and Cereal Products, Sugar and Sugar Products
10.1 Cereals and Cereal Products Preservation
10.2 Sugar and Sugar Products
11 Contamination, Prerservation and Spoilage of Fruits and Vegetables
11.1 Fruits- Maturation, Ripening and Storage
Preservation of Fruits
11.2 Vegetables
12 Contamination, Preservation and Spoilage of Meat and Meat Products
Contamination
Preservation
Questions
Golden Rice
Methodology
13 Contamination, Preservation and Spoilage of Fish and Sea Foods
13.1 Contamination.
13.2 Preservation.
13.3 Spoilage
14 Contamination, Preservation and Spoilage of Eggs and Poultry
14.1 EGGS
14.1.1 EGGS Contamination
14.1.2 Preservaton
Preservation of EGGS Products
14.1.3 EGGS Spoilage.
14.2 Poultry
14.2.1 Contamination
14.2.2 Preservation
14.2.3 Microbial Spoilage of Poultry
15 Contamination, Preservation and Spoilage of Milk and Milk Products
15.1 Contamination
15.2 Preservation
15.3 Spoilage
Types of Microbial Spoilage
16 Contamination, Preservation and Spoilage of Canned Foods & Bottled Beverages
16.1 Canned Foods-Preservation
16.2 Contamination.
16.3 Spoilage of Canned Foods
16.4 Bottled Beverages
17 Food Poisoning
17.1 Food Intoxication
17.1.1 Botulism.
17.1.2 Staphylococcus enterotoxicosis
17.1.3 Bacillus cereus Gastroenteritis.
17.2 Food Infection
17.2.1 Salmonellosis.
17.2.2 Clostridium perfringens.
17.2.3 Vibrio parahaemolyticus
17.2.4 Camylobacter jejuni
17.2.5 Listeria monocytogenes.
17.2.7 Shigellosis
17.2.8 Yersiniosis.
17.3 Prevention of Food Poisoning.
17.2.6 Enteropathogenic Escherichia coli.
18 Mycotoxins
18.1 Nature of Mycotoxicoses Nature of Mycotoxin
18.2 Aflatoxins.
18.3 Food Safety
- Requirement for Proper Storage Conditions
- Minimizing Mechanical Damage
- Minimizing Insect Damage
- Sanitation of Storage Facility
- Mycotozin Tolerant Hybrids 6. Detoxification.
Genetically Modified Foods
Genetic Engineering
19 Advantages of Genetically Modified Foods
19.1 Application of Genetic Engineering in Crop Improvement
- Pest Resistance
- Disease Resistance
- Improved Quality of Foods
- Herbicide Resistance
- Adaptation to Harsh Growing Conditions.
- Nutritional Value of Crops.
- Reduction of Antinutritional Factors
19.2 Transgenic Animals
19.3 Food Safety Concerns Expressed About GM Foods
19.4 Conclusions
Experiments in Food and Dairy Microbiology
Ex.No.1 Microbial Spoilage of Fruits
Ex.No.2 Microbial Spoilage of Vegetables
Ex.No.3 Spoilage of Bakery Products
Ex.No.4 Microbial Spoilage of Sea Foods.
Ex.No.5 Isolation of Mycotoxigenic Fungi From Food Grains
Ex.No.6 Direct Microscopic Method of Counting Bacteria in Liquid Foods.
Ex.No.7 Examination of Unspoiled canned Food for Sterility and Quality.
Ex.No.8 Isolation of Lactic Acid Bacteria From Curd
Ex.No.9 Isolation and Enumeration of Yeast From Rice Batter
Ex.No.10 Presumptive Test for Detecting Coliform Bacteria in Foods
Ex.No.11 Enumeration of Coliforms in Foods by MPN Method.
Ex.No.12 Resazurin Test
Ex.No.13 Methylene Blue Reduction Test.
Ex.No.14 Role of Yeasts in Bread Making
Ex.No.15 Production of Single Cell Protein (SCP)