Fermented milk products, also known as cultured dairy foods, cultured dairy products, or cultured milk products, are dairy foods that have been fermented with lactic acid bacteria. This particular presentation describes all the fermented milk products like yoghurt, cheese etc. VIEW, SHARE, ENJOY!

1. PRODUCTS
-Saugat Bhattacharjee
ABBS

2. INTRODUCTION
 Milk is a whitish liquid containing proteins, fats, lactose , various
vitamins and minerals that is produced by the mamary glands of all
mature female
 the milk of cows, goats and other animals used as food b humans
 mik is extremely perishable and many ways have been developed to
preserve it
The earliest method which have been used for many thousands of
years is fermentation
Fermentation is a metabolic process in which an organism convert a
carbohydrate such as starch and sugar into an alcohol or an acid
Example yeast perform fermentationto obtain energy by converting
sugar into alcohol
Bacteria perform fermentation by converting carbohydrates into
lactic acid

3. HISTORY OF FRMENETATION
It is a natural process
People applied fermentation to make products such as
wine ,cheese ,beer etc.
In 1850s and1860s Louis Paster became the first scientist
to study fermentation when he demonstrated
fermentation was caused by living cells
He showed that lactic acid fermentation is caused by
living organism
In 1860 he demonstrated that bacteria cause souring in
milk a process formely thought to be merely chemical
change and his work in identifying the role of
microorganism in food spoilage lead to the process of
pasteurization

5. Fermented milk product
Yoghurt
Cultured
butter
milk
cheese

6. Cheese

7. TYPES OF CHEESE
I. Soft cheese
II. Semi soft cheese
III. Semi hard cheese
IV. Hard cheese
V. Fresh cheese
VI. Blue cheese
VII.Processed cheese

8. SOFT CHEESE
Examples of soft cheese are camembert, feta, celtic etc.
This type of cheese does not undergo any heating or presseing
A penicillium fungus gives it furry white rind
Not usually used in cooking soft cheese are used to spread on bread or
crackers
Wine to serve is beaujolous
The organisms found is streptococcus cremoris , penicillium camemberti
found in camembert
Celtic cheese

9. Streptococcus cremoris
Penicillium camemberti

10. SEMI SOFT CHEESE
Examples are gouda, port soft, muenster
This type of cheese does not undergo any heating or pressing
The rind is rinsed and brshed with a solution of salt water enriched
with a specific bacteria , which encourages orange coloured fungi to
appear
Ideal for snacking or deserts, some semi soft cheese may be used for
cooking if they stand up to heat well enough
Wine to serve is red bordeaux
The organisms found are lactococcus lactis found in
gouda, brevibacterium linens found in muenster

11. HARD CHEESE
Examples aged
manchego, mimolette, tuscano, pelorina etc
A hard cheese needs to have less water content (30%
to 48% ) in the end product than a soft cheese (
which has 50% to 70%)
Packed into moulds , firmly pressed and stored for
long periods ( up to two years ) they bocome hard and
more pungent over time
Wine to serve them red wine as burguncly

12. SEMI HARD CHEESE
Examples are cheddar ,edam , emmental, cantal etc
These cheese onces transformed into curds are heated
, pressed, moulded and left to ferment .
This is how the famous holes appear in cheese that is
stored in cellars ( such as emmental )
They are very rich in calcium
Maturing can take from three to nine months or even
longer
Wine serve full bodied red wines such as rioja
The organism found are lactobacillus casei, streptococcus
cremoris found in cheddar

13. Streptococcus cremoris

14. BLUE CHEESE
Examples are roquefort , gorgonzola , stilton
The production of this cheese involves inoculating it with fine long
skewers containing penicillium cultures which allow mould to
develop in the cheese
This is what produce the green or blue veins
Wine to serve is sweet wines , loupiac sauternes
The organisms found are penicillium roqueforti and lactococcus
lastis in roquefort

15. Penicillium roquefort

16. FRESH CHEESE
Examples are cottage , mozzarella and fromage frains
COTTAGE CHEESE
This is fresh cheese with 80% water content
Milk is curdled an drained but little other processing takes place and
there is no ageing
Cattage cheese is typically eaten with fruits or in salad
MOZZARELLA
This cheese is obtained through kneading and stretching the curd
until it reaches the desired consistency
Mozzaella is often used in pizza and lesagine
FROMAGE FRAINS
This cheese is hardly drained or matured
Its milk proteins simply coagulate under the effect of lactic ferments
It can be eaten on its own or with added flavouring

17. Cottage cheese

18. PROCESSED CHEESE
This cheese is made up of a mixture of cheese , butter, cream and milk
that is heated and emulsified
Some varieties are flavoured or spiced
The shelf life is generally very long
Cheese are also classified as unriped if produced by single step
fermentation or ripened if addition growth is required during
maturation of cheese to achive the desired taste , texture and aroma
Ripening involves additional enzymatic transformations after the
formation of cheese curd
Various fungi are also used in the ripening of different cheese
The unriped cheese is inoculated with fungal spores

19. PRODUCTION OF CHEESE
Basic stages involved in cheese making are as follows :
Standardization; this is done to adjust fat or to have balanced ratio of fat
to casein or increasing fat through cream for making cream cheese
Clarification; effective alternative to filtration for the removal of
extraneous matter, leucocytes and some bacteria , it is carried out at 32c to
35c centrifugally
Bacterofugation; if centrifuged milk is passed through the unit a seond
time about 90% of the remaing 10% is removed, thus total 99% bacteria can
be removed
Homogenization; milk is homogenized at low pressure to reduce whey
exudation from the coagulum, to make cheese white and promote fat
hydrolysis
Thermization ; the raw milk is stored for few days before using it for
cheese making, it is subjected to heat treatment at 63C for 10 to 15 seconds
and cooled at 5C

20. Ultrafiltration; by membrane filtration under low pressure milk can be
sepaated into retentate with fats , casein, whey proteins
Ripening of milk; this is achieved by heating the milk to 30 to 33C and
adding starter bacteria eg. Lactococcus lactis , which has the effect of
speeding up the natural process of milk souring
Rennetting; after increase in acidity of milk created by startee rennet
extract is added to milk and uniformly distributed to efffect coagulation of
milk eg of coagulating enzyme is bacillus sutilis or mucor meihei
Cutting the coagulum; this has a great effect it release a large volume of
whey,establishes the size of the curd particle
Scalding; in high scalding the temperature may be 52 to 58 C , in medium
scald 30 to 42C and in low scald is 30 to 35C . During combined action of
stirring and heat , lactic acid in curd particles is formed by the starter
organism
Draining the whey; the cud is allowed to settle, acidity is measured untill
it reaches the desired level
Milling; milling of the texturized matted curd is done at 0.6 to 0.7C
acidity helps in distribution of salt which act as preservative

21. Pressing; the curd is filled in moulds and pressed, the degree varies with
the type of cheese
Dressing and package ; the green cheese is packed in heat shrink barrier
film

23. YOGHURT

24. Yoghurt is produced by the controlled fermentation of milk
by two species of bacteria Lactobacillus bulgaricus and L
actotococcus thermophilus (streptococcus thermophilus)
The sugar in milk is called lactose which is fermented to
acid ( lactic acid) and it is the one which cause he
characteristic curd to form
Streptococcus thermophilus bring the pH of the milk down
to 5.5
Lactobacillus bulgaricus convert lactose to lactic acid
Proteolytic enzymes from L . bulgaricus break down milk
protein into peptide s
These peptides stimulate the growth of L . themophilus
which in turn produces formic acid and carbondioxide
These are the growth stimulants for the L . Bulgaricus

25. Lactobacillus bulgaricus
Streptococcus thermophilus

26. TYPES OF YOGHURT
I.
II.
III.
IV.
V.
VI.
Set yoghurt
Stirred yoghurt
Drinking yoghurt
Flavored yoghurt
Concentrated yoghurt
Frozen yoghurt

27. Set yoghurt
A solid set where by the yoghurt
firms in a container and not
disturbed, its incubated and
cooled in the final package .
The firm is jelly like texture

28. Stirred yoghurt
Made in large container then
stirred or otherwise dispensed into
secondary serving containers .
The consistency of the set is
broken and the texture is less firm
than set yoghurt

29. Drinking yoghurt
Stirred yoghurt to which addition
milk and flavours are mixed in.
a fruit or fruit syrups is added
mixed in milk to achieve the
desired thickness.
The shelf life of this product is 4
to 10 days , since the pH is raised by
fresh milk addition.
Commericialproducts
recommend a thoroughly shafe
before consumption

30. Flavored yoghurt
Fruits , fruits syrups or pie filling
can be added to the yoghurt just
before poured into pots , it usually
contain about 50% sugar

31. Concentrated
yoghurt
Incubated like stirred yoghurt after
coagulation is broken some water
is boiled off producing a rough
and grlty textures

32. Frozen yoghurt
Incubated like stirred yoghurt
, cooling is achieved by pumping
through a freezer like ice cream, it
has a texture like ice cream

33. PRODUCTION OF YOGHURT
Raw milk is taken which have low count of organisms and substances which
suppress the development of starter microbes eg. Streptococcus thermophilus
Standardization of fats; this involves the removal of fat content of milk , mixing
full cream milk with skim milk or by using standardizing centrifuge
Homogenization; is done by first pre treating it to 60 to 65C and passing it
through an homogenizer at 100 to 200 kg/cm2 to stabilize the product and
provide smooth texture
Heat treat; this involves heating the milk at 90 to 95 for 5mins to improve the
texture of yoghurt
Cooling ; after heating the substrate is cooled to incubation temperature 42 to
45 C
The culture contain two strains of microorganism streptococcus salivarius and
lactobacillus delbrueckii

36. BUTTER MILK

37. BUTTER MILK
It is a fermented milk product made by using mesophilic starters
Different products are produced by using different stains of lactic acid bacteria
as starter cultures and different fractious of whole milk as the starting substrate
Sour cream uses streptococcus cremoris or S. lactis for producing lactic acid
and leuconostoc cremoris for characteristic flavour
Cream is starting substrate , butter is normally made by churning cream that
has been soured by lacctic accid bacteria
Streptococcus cremoris or S.lactis is used to produce lactic acid rapidly and
leuconostoc citrovorum produce necessary flavors

38. PRODUCTION OF BUTTER MILK
Fresh or skim milk is taken and standardise making it free from antibiotics
and detergents
Milk is homogenized at 200 kg/cm2 at 15C then heat treated at 90C for 13
mins to get satisfactory end product
Then it is cooled to 23C and inoculated wit a mixed culture having
lactococcus lactis and leuconostoc citrovorum as primary produces of aroma
and flavour
The inoculation may range from 1 to 2%
When acidity reaches 0.9% the product is gently mixed , cooled bottled
and stored at 5C
The fermentation time may be around 16 to 20 hrs
The final product is a viscous drink with pleasing aroma and flavour