This document discusses various fermented milk products including cheese, yogurt, buttermilk, acidophilus milk, and kefir. It provides details on the production processes and microorganisms involved for each product. Cheese production involves coagulation of milk proteins followed by separation of curds and whey. Most cheeses then undergo ripening through microbial activity. Yogurt is produced by incubating milk with starter cultures at elevated temperatures to produce lactic acid. Buttermilk and acidophilus milk also involve lactic acid bacterial cultures. Kefir uses kefir grains containing various microbes. The document categorizes cheeses and describes characteristics of common types.

1. Cheese
Yogurt
Cultured
buttermilk
Acidophilus
milk
Kefir
Fermented Milk Products

2. What is whey?
• Whey or milk plasma is the liquid remaining after milk has been
curdled and strained
• used to produce ricotta, brown cheeses. It is also an additive in many
processed foods, including breads, crackers and commercial pastry,
and in animal feed.

3. Cheese

4. Cheese
• Traditionally…
• Cheese was a way of preserving the nutrients of milk.
• Cheese
• Is the fresh or ripened product obtained after coagulation and whey
separation of milk, cream or partly skimmed milk, buttermilk or mixture of
these products.

5. Microorganisms in Food and Beverage
Production
• Cheese production
• Cottage cheese easiest cheese to
make
• Pasteurized milk inoculated with
starter culture
• Culture causes milk proteins to
coagulate
• Coagulated proteins called curd
• Curd heated and cut into small pieces
to facilitate drainage of liquid waste
• Waste termed whey

6. • Cheese production
• Most other cheeses undergo further microbial processing
termed ripening or curing
• Cottage cheese is unripened
• Enzyme rennin is added to fermenting milk to hasten protein
coagulation
• Curds salted after whey is separated and pressed and ripened
to encourage changes in texture and flavor
• Ripening can take weeks to years
• Longer ripening produces more acidic sharper cheese
• Certain organisms produce certain characteristics
» Propionibacterium shermanii  Swiss cheese
» Penicillium roquefortii  Roquefort, and gorgonzola
Microorganisms in Food and Beverage Production

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. Types Of Cheese (Examples)
1. Soft cheese (camembert, feta, etc.)
2. Semi soft cheese (gouda, port soft, etc.)
3. Hard cheese (mimolette, pelorina, etc.)
4. Semi hard cheese (cheddar, cantal, etc.)
Blue cheese (roquefort, stilton, etc.)
5. Fresh cheese (cottage cheese, mozzarella, etc.)
6. Processed cheese

9. Types Of Cheese (organisms used)
1. Soft cheese (Streptococcus cremoris, Penicillium camemberti)
2. Semi soft cheese (Lactococcus lactis, Brevibacterium linens)
3. Hard cheese (Lactobacillus casei, Lactobacillus plantarum)
4. Semi hard cheese (Lactobacillus casei, Streptococcus cremoris)
Blue cheese (Penicillium roqueforti, Lactococcus lactis)
5. Fresh cheese (Streptococcus sp.)
6. Processed cheese (fungi or fungal spores used during ripening)

10. SOFT CHEESE
Examples of soft cheese are camembert, feta, celtic etc.
This type of cheese does not undergo any heating or
pressing
Water content 50% to 70%
A Penicillium fungus gives it furry white rind
Not usually used in cooking, soft cheese are used to spread
on bread or crackers
The organisms found is streptococcus cremoris , penicillium
camemberti found in camembert.
Celtic cheese

11. 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 brushed 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
The organisms found are Lactococcus lactis found in gouda, Brevibacterium linens
found in muenster

12. 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 become hard and more pungent over time

13. SEMI HARD CHEESE
Examples are cheddar ,edam , emmental, cantal etc
These cheese once 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
The organism found are Lactobacillus casei, Streptococcus cremoris found in
cheddar

14. BLUE CHEESE (Semi-hard 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
The organisms found are Penicillium roqueforti and Lactococcus lastis in roquefort

15. 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
Cottage 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
Mozzarella is often used in pizza and lasagne
Paneer - Cultured (soured) milk pressed into a sliceable cheese with a crumbly, creamy texture
that does not entirely melt.

16. PROCESSED CHEESE (eg. Cheddar)
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
Various fungi are also used in the ripening of different cheese
The unriped cheese is inoculated with fungal spores

17. Cheddar cheese
made from whole milk
<39% moisture, 48% fat
Orange-yellow
Ripened
Lac. lactis ssp. cremoris or lactis.
Leuconostoc for flavour

18. Swiss Cheese
Made from partially skimmed milk (cow’s milk)
Coagulated with acid and rennin
It is hard (41% moisture, 43% fat)
Sweet taste due to proline and a nutty flavour

20. • Yogurt
• Pasteurized milk is concentrated slightly then inoculated with
starter culture
• Mixture is incubated for several hours at 40° C - 45° C
• Thermophilic bacteria grow rapidly at higher temperatures
• Produce lactic acid and other end products
• Contribute to flavor
• Controlled incubation ensures proper levels of acid and flavor
compounds
Microorganisms in Food and Beverage
Production

21. Types Of Yogurt
Set yogurt Stirred yogurt Drinking yogurt
Flavoured yogurt Concentrated /greek yogurt Frozen yogurt

23. •Acidophilus milk
• Sweet acidophilus milk retains flavor of fresh
milk because it is not fermented
• Culture is added immediately before packaging
• Bacteria are added for purported health benefits
• Prevent and reduce severity of some diarrheal diseases
Microorganisms in Food and Beverage
Production

24. Production Of Acidophilus Milk

25. Lactobacillus acidophilus
L. Acidophilus in a soya medium

26. Buttermilk
• Buttermilk is a by-product of the butter industry and
• Can be condensed, dried, or mixed with skim milk
• Has a higher fat content
than milk!

27. Production Of Cultured Buttermilk

28. Kefir
It is produced by adding a starter culture called “kefir grains” directly
to milk.
Traditionally prepared kefir contained 1-2% alcohol, due to the
complex fermentative process of kefir grains. But new and improved
production methods have resulted in much lower levels.

29. Wide range of flavoured kefir
Kefir grains