This document discusses the applications of biotechnology in dairy products. It describes how biotechnology has been used for centuries in dairy production through starter cultures or enzymes. Some key dairy products developed through biotechnology are cultured butter, cheese, yogurt, cultured cream, and acidophilus milk. Each product uses different bacterial cultures that aid in fermentation. The fermentation process results in chemical changes like lactose conversion and protein breakdown, as well as physical changes like coagulation and texture alterations.

2. Applications of biotechnology in dairy
products
Presented by:
• Zarnab Ashraf

3. Introduction:
The exploitation of biological processes for industrial and other
purposes, especially the genetic manipulation of
microorganisms for the production of antibiotics, hormones,
etc.
In manufacture of dairy products, biotechnology has been
used for many centuries (cultured milk products, cheeses,
processed milk by products) either using starter cultures or
enzymes for milk clotting, cheese ripening acceleration, fat,
protein or lactose hydrolyzate production or antimicrobial
purposes.

4. Products of dairy biotechnology:
1. Cultured butter
2. Cheese
3. Yogurt
4. Cultured cream (sour cream)
5. Acidophilus milk

5. Cultured butter
• This is a ripened or lactic butter made from soured cream.
• The cream is cultured before churning for specific reason:
• Adding a lactic acid-producing culture to acidify the cream
before churning helped to separate the butterfat during the
churning process.

6. Making process:

7. Cultures used:
• Mixture of both acid producing organisms (Lactococcus lactis
and L. cremoris) and flavor producing organisms (S. lactis
subsp. diacetylactis, Leuconostoc citrovorum)
• In ratio of 0.5-2 % of weight of cream.
• Incubate at 21 C.
C12H22O11 (lactose) + H20 → 2C3H6O3 (lactate) + 2C2H5OH
(Ethanol) + 2CO2

8. Changes in butter:
• Chemical changing:
• During fermentation, the cream sours as bacteria
convert milk sugars into lactic acid. Fermentation
produces additional aroma compounds, which makes a
fuller-flavored, more “buttery” tasting product.
• Physical changing:
• Butter made from a fermented cream is known
as cultured butter. End of cooking, giving the sauce a
thicker body and a glossy shine.

9. Cheese:
• Cheese is a dairy product derived from milk that is produced in
a wide range of flavors, textures, and forms by coagulation of
the milk protein casein. It comprises proteins and fat from milk,
usually the milk of cows, buffalo, goats, or sheep. During
production, the milk is usually acidified, and adding the
enzyme rennet causes coagulation. The solids are separated
and pressed into final form. Some cheeses have molds on the
rind, the outer layer, or throughout. Most cheeses melt at
cooking temperature.

10. Rennet:
• Chymosin, its key component, is a protease enzyme
that curdles the casein in milk. In addition to chymosin,
rennet contains other enzymes, such as pepsin and a
lipase. Rennet is used to separate milk into solid curds
(for cheese making) and liquid whey, and so is used in
the production of most cheeses

11. Culture used:
Lactococcus lactis subsp. cremoris
Lactococcus lactis subsp. lactis

12. Physical changes:
• The rennet causes a chemical reaction where the milk
solids curdle, separating themselves from the whey, or
liquid portion of the milk.
Chemical changes:
• Protein denaturing.
• Coagulation.
• Breakdown of proteins, lipids and carbohydrates (acids
and sugars) which releases flavour compounds and
modifies .

13. Yogurt:
• Yogurt or yoghurt, is a fermented dairy food produced by
bacterial fermentation of milk. The milk is converted into
a curd which is formed by the coagulation of proteins.
Brands of yoghurt in Pakistan
• Nestle
• Prema
• Adams
• Anhaar

14. Yogurt cultures
• The bacteria used to make yogurt are known as yogurt
cultures.
• Streptococcus thermophillus
• Lactobacillus bulgaricus
Properties:
It has smooth texture, acetaldehydic or diacetyl flavour
and slightly acidic taste. Good source of nutrition and
beneficial for health. Also used in making many foods.

15. Cultured cream (sour cream)
• Cultured cream is cream that has gone through a
fermentation process. This process consists of the
bacteria converting milk sugars into lactic acid.
Cultured dairy products have a tangy flavor that can
enhance many dishes.
Uses:
To make cultured butters
To make cream spreads and sauces.

16. Starter culture of sour cream
• The starter cultures typically used for making sour
cream are aromatic starters i.e, Lc. lactis subsp. lactis
biovar.
Physical and chemical changes:
• When cream is heated to temperatures above 70 °C,
there is denaturation of whey proteins. To avoid phase
separation brought on by the increased surface area, the
fat globules readily bind with the denatured β-
lactoglobulin.

17. Acidophilus milk
• Acidophilus milk is a type of fermented dairy product
and L. acidophilus is used as culture. It is a probiotic
drink.

18. Cultures used:
Lactobacillus acidophilus
Reactions:
Lactose → Lactate +CO2

19. Cont………….
• Probiotics suggested levels in fermented milk range
from 106-109 colony-forming units per milliliter
(CFU/mL).
• A fermented milk produced by growing the bacterium
Lactobacillus acidophilus in milk, used in medicine to
alter the microbial flora of the intestinal tract under
certain conditions.