• Production of Cheese
• Production of Fermented milks:
e. Acidophilus milk
CHEESE : a fermented food product
• It is a dairy fermented food product which is made from milk .
• All cheese result from lactic acid fermentation of milk which result
in coagulation of milk protein.
• Lactococcus lactis is used as starter culture.
Raw milk is obtained
Cooled at 32 degree
The cheese curd is packed
for ripening with or without
Processed cheese is
Cheeses are Classified by degree of hardness and texture
Soft cheeses Semisoft cheeses Hard cheeses
Softer cheeses are ripened by aerobic bacterium and
molds on surface
soft cheese are ripened for only about 1 to 5 month
Ripened by lactic acid
bacteria in interior
hard cheese are ripened
for 3 to 12 month
Feta , blue cheese Swiss cheese
• 1. Cheddar (lactococcus lactis)
Cheddar is a hard variety with about 40% moisture and has a diverse
selection of tastes that range from mild to sharp. This is dependent upon the
age of the cheese.
2. Swiss (Propionibacterium)
Swiss cheese is a firm cheese with a sweet, mildly nutty flavour. This cheese
is known for the holes or eye formation that develop as it ripens. These holes
or eyes range in diameter from ½ inch to 1 inch and begin forming when the
cheese is about 3 weeks old.
• 3. Camembert (Penicillium camemberti)
• Camembert has a soft texture with a buttery taste and mushroom smell. It
tastes best when it is at room temperature and the center becomes soft
and it is a mold-ripened cheese.
Substrate and microorganism used in fermented milk production
Foods and products Raw ingredients Fermenting organism
Kumiss Raw mare’s milk Lactobacillus leichmannii, Lactobacillus
delbrueckii subspecies bulgaricus, “torula spp.”
Kefir milk Lactococcus lactis, Lactobacillus delbrueckii
subspecies bulgaricus, “torula spp.”
Yogurt Milk , milk solid Streptococcus thermophilus and Lactobacillus
delbrueckii subspecies bulgaricus
Acidophilus milk Milk Lactobacillus acidophilus
• Kefir is produced by Yeast-lactic fermentations.
• product has an ethanol concentration of up to 2%.
• Kefir products tend to be foamy and frothy, due to active
carbon production. The co2 produced during fermentation
carbonate the drink.
• It is produced by e use of kefir “grains” as an inoculum
which contain two species of bacteria and yeasts held
together by coagulating milk.
• Kafiran is a water soluble polysaccharide which account for
24% of kefir grain.
Organism used: Lactococcus lactis,
Lactobacillus delbrueckii subspecies
bulgaricus, “torula spp.”
Koumiss : produced in Russia.
• It is a fizzy, greyish white drink , traditionally made from mare’s milk.
• Starter culture: Lactobacillus leichmannii, Lactobacillus delbrueckii
subspecies bulgaricus, “torula spp.” and lactose fermenting yeast.
• The final product contain about 2% alcohol and acidity up to 1.4%
mixed yeast and
These bacteria dispersed throughout
the product and don’t form discrete
• Yogurt is a semisolid fermented milk product, produced by the
action of two bacteria – Streptococcus thermophilus and
Lactobacillus delbrueckii ssp. bulgaricus.
• In addition, yogurt may contain bifidobacteria and supplementary
flora like Lactobacillus acidophilus for improving its therapeutic
Water content of milk is
reduced by adding milk solids
Homogenization is the process of
breaking down the fat molecules
in milk so that they stay
integrated rather than separating
as cream. homogenization also
prevents creaming and wheying
off during incubation and storage.
Stability, consistency, body and
texture are enhanced by
Standardization of milk
refers to the adjustment
which means rising or
lowering of fat
Flowchart of yogurt
• Probiotics have been defined as selected viable microorganisms used as
dietary supplements .having potential for improving health or nutrition of
man or animal following ingestion.
• Milk products also serve as the important delivery vehicles for probiotic
bacteria Most of them can readily utilize lactose as an energy source for
• The primary probiotic bacteria associated with dairy products are
Lactobacillus acidophilus, Lactobacillus casei and bifidobacteria
Acidophilus milk is produced by using Lactobacillus acidophilus .
• L. acidophilus may modify the microbial flora in the lower intestine, thus
improving general health, and it often is used as a dietary adjunct.
• Many microorganisms in fermented dairy products stabilize the bowel micro
flora, and some appear to have antimicrobial properties.
• It minimizing lactose intolerance, lowering serum cholesterol, and possibly
exhibiting anticancer activity.
• Several lactobacilli have antitumor compounds in their cell walls. Such
findings suggest that diets including lactic acid bacteria, especially L.
acidophilus, may contribute to the control of colon cancer
Hold the product at 37 0C
until a smooth curd develop