MILK

1
MILK MILK PRODUCTS

• Chapter 13

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Constituents of Milk

• Fat (3.9)
• Protein (3.3)
• Lactose (5.0)
• Minerals (0.7)
• Water (87.1)

3
Fluid Milk Processing
Clarification
Pasteurization
Fat Adjustment
Homogenization
Packaging
Market
4
Clarification

• Centrifugal operation
• Removes sediment
• Body cells from udder

5
Pasteurization

• Kill disease causing organisms
• Coxiella burnetii is the toughest to kill
• Use
• 63oC (145oF) for 30 min.
• or
• 72oC (161oF) for 15 sec. (HTST)

6
Homogenization

• Forces milk through small orifices or turbulent
  flow paths
• Subdivides fat globules clumps into small
  particles to prevent floating
• Gives milk a whiter color

7
Fluid Milk Products

• Vitamin D Milk
• Multivitamin Milk
• Low-Sodium Milk
• Low-Lactose Milk
• Evaporated Milk
• Sweetened Condensed Milk

8
Ice Cream Contents

• Whole milk
• Skim milk
• Cream
• Frozen cream
• Butter
• Butter oil
• Condensed milk

• Dried milk
• Sugar
• Stabilizer
• Emulsifier
• Flavorings
• Water
• Air

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Typical Composition of Ice Cream

• 12 fat
• 11 MSNF
• 15 sugar
• 0.2 stabilizer
• 0.2 emulsifier
• Trace of flavorings (vanilla)
• Nuts, fruit, chocolate. etc.

10
Ice Cream Manufacturing

• Mix ingredients heat to 43oC
• Pasteurize
• (71oC for 30 min, or 82oC for 25 sec.)
• Homogenize at 2500 psi
• Aging for 3 to 24 hrs at 4.4oC
• Freezing
• Hardening

11
CHEESE DEFINED

• Product made from curd of milk from cows or
  other animals through coagulation of casein with
  enzyme (rennin), acid (usually lactic), and with
  or without treatment with heat, pressure, salt,
  and ripening (fermentation) by microorganisms.

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CHEESE CLASSIFICATION

• SOFT
• Unripened
• Low fat cottage cheese
• High fat Cream cheese
• Ripened Brie
• SEMISOFT
• Ripened by bacteria brick, Munster
• Ripened by bacteria surface micro Limburger
• Ripened by interior blue mold Roquefort, Blue

13
CHEESE CLASSIFICATION

• HARD
• Ripened by bacteria w/o eyes Cheddar
• Ripened by bacteria w/ eyes Swiss
• VERY HARD (grating)
• Ripened by bacteria Parmesan
• PROCESS CHEESES Pasteurized American
• WHEY CHEESES Ricotta

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• MILK COMPONENTS
• Fat
• Protein (casein)
• Lactose
• Minerals
• Water

• CHEESE
• TERMS
• Curd coagulated protein entrapping some fat,
  lactose, water minerals
• Whey Remaining dissolved lactose, proteins,
  minerals water

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CHEDDAR CHEESE PROCESS

• Pasteurized whole milk is heated to 31oC in vat
  and stirred
• Streptococcus lactis starter culture added
• Coloring added
• After 30 min, acidity has increased and rennin is
  added
• stirring is stopped mixture sets for 30 min.

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• Custardlike curd forms in 30 min.
• Acid production continues
• Curd is cut into 1/2 in. cubes
• Heated to 38oC for about 1 hour to increase acid
  production and release whey
• Whey is drained and individual curds are matted
  together
• The matted curd is cut into blocks and
  stacked/restacked to remove whey (cheddaring)

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• Curd blocks are milled into small pieces and
  salted
• Curd pieces are pressed overnight at 20 psi to
  remove remaining whey and shape the cheese
• Cheese placed in cool room at 16oC and 60 RH for
  3-4 days for rind development
• Then wrapped in film or dipped in hot paraffin
• Ripening for 60 days to 12 months

19
COTTAGE CHEESE PROCESS

• Past., skim milk heated to 22oC
• Streptococcus lactis and Leuconostoc citrovum
  (flavor producing) is added
• Fermented for 14 hrs
• Curd cut into small pieces and cooked for 90 min
  with stirring

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• Whey is drained curd is washed with cold water
• Curd is salted
• Mixed with cream to give 2 or 4 fat (creamed
  cottage cheese)

21
SWISS CHEESE PROCESS

• Process is similar to Cheddar except that
  Propionibacterium shermanii and other lactic acid
  bacteria are added in addition to S. lactis. P.
  shermanii ferments lactic acid into propionic
  acid and CO2.