Milk & Types of Milks

Milk is a whole, clean, lacteal secretion obtained by the complete milking of healthy milch animals, properly fed and kept, excluding that obtained within 15 days before and 5 days after calving.

TYPES OF MARKET MILK:

• WHOLE MILK - Milk as such, derived from the animals without altering the composition is termed as whole milk. Cow milk contains fat not less than 3.5% and S.N.F. not less than 8.5%, Buffalo milk contain fat not less than 6% and SNF not less than 9%.

• STANDARDIZED MILK - The standardization can be done by partially skimming the fat in the milk or admixing skim milk in proper proportions. the standardized milk should contain a minimum of 4.5% fat and 8.5% SNF.

• TONNED MILK - Milk obtained by the addition of water and skim milk powder to whole milk.  toned milk should contain a minimum of 3% fat and 8.5% SNF.

• DOUBLE TONNED MILK - It is similar to toned milk,  double toned milk should contain a minimum of 1.5%  fat and 9%  SNF.

• RECONSTITUTED MILK - This  milk prepared by dispersing whole milk powder in water approximately in proportion of I part powder to 7-8 parts water.

• RECOMBINED MILK - The product obtained when butter oil, skim milk powder and water are combined in the correct proportion to yield fluid milk.  The milk fat may also be obtained from other sources, like unsalted butter, fresh sweet cream or plastic cream.   recombined milk should contain a minimum 3% fat and 8.5% SNF.

• FILLED MILK - Milk fat is substituted with some vegetable oil or fat, it is termed as filled Milk.

Alcohol Test for assessing Raw milk quality

Use:

    Test for screening, rapid assessment of acidity.

Principle:

    Proteins in milk that has become sour will coagulate when mixed with alcohol. The sour is because of lactic acid formation.

Equipments and Materials:

• Milk Sample
• Test tube
  
• Milk Pipette (10.75ml)
• Dropper
• 68% Ethanol solution (by weight: e.g. mix 68 ml 96% alcohol with 28 ml distilled water) or 75 % ethyl alcohol by volume (density 0.8675 g/ml at 27 °C).

Procedure:

• Take a test tube.
• Using 10.75ml milk pipette, take 5ml of milk sample and pour into the test tube.
• Using dropper, take 5ml of 68% Ethanol solution and pour into the test tube.
• Agitate the test tube by gentle moment.
• Observe the milk sample is coagulate or not.

 Note: The volume of the ethanol solution taken should be same as the volume of milk sample taken.

Observation:

    If the milk acidity is more than 0.21%, then the milk is abnormal and coagulate. This milk will not pass the test for further processing.