3. What is microbiology of milk?
Basically it is the study of milk and the microorganisms which are present in
the milk
Like : bacteria, virus, protozoal parasites and fungi
4. Introduction about milk!
Actually it’s the white liquid produced by the mammary
gland of animals
Rich in fat and protein
Also contain lactose, and various vitamins and minerals
Primary source of nutrition for young mamals before they
are able to digest other type of food
5. Properties
Milk is white emulsion or colloid of butter fat globules
Presence of fat globules and the smaller casein micelles
provide the opacity to the milk
Yellow-orange carotene imparts the creamy yellow colour
to a glass of milk
It contains many other nutrient
6. Milk contain 30-35 grams of protein per liter of which about
80% is arranged in cassien micelles
Different carbohydrates including lactose, glucose,
galactose, and other oligosaccahrides
Calcium, phosphate, magnesium, sodium, potassium,
citrate, and chlorine, all are included
Vitamins A, B6 ,C, D, K, E, B12, thiamine, niacin, biotin,
riboflavin,folates and pantothenic acid are all present in the
milk
7. Types of microbes
There are two types of microbes
Favourable and pathogenic
8. Favourable:
These are those microbes which brings favourable changes
in flavour and appearance
For example: Lactobacillus, Streptococcus
Pathogenic:
These are those which may cause disease
For example:Bassilus cereus, listeria monocytogenes
10. How milk is contaminated?
Milk is sterile at the secretion in the udder but is
contaminated by bacteria even before it leaves the udder
Further infection of the milk by microorganism can take
place during milking, handling, storage and other pre-
processing activities
Milk sport the growth of variety of bacteria including
pathogenic one
13. Spoilage is a term used to describe the deterioration of
foods’ texture, colour, odour or flavour to the point where it
is unappetizing or unstable for human consumption
Microbial spoilage of food often involves the degradation
of protein, carbohydrates, and fats by the microorganisms
or their enzymes
Bacillus, Clostridium, Cornebacterium, Arthrobectar,
Lactobacillus, Microbacterium, Micrococcus, and
Streptococcus
14. Milk pasteurization
It is the process used to destroy bacteria in milk
Milk is heated to a sufficient temperature to kill pathogenic
bacteria
It also kills many non-pathogenic organisms and thereby
extends the storage stability of milk
Most commonly heating milk upto atleast 161.1 degrees
Fahrenhiet for 15 seconds
15. Milk sterilization
It is aimed to killing all organisms, eliminating all growth
forms of bacteria
Sterilized by heating at high temperature for few seconds to
kill the bacteria
Enabling the milk to stored for long period of time at room
temperature