ULTRASONIC PORTABLE MILK ANALYZER
w w w . m i l k o t e s t e r . c o m
CHAPTER THREE
Samples preparation
In order that most accurate results are obtained it is important that
the milk be kept for 2 hours after milking and stirred well before being
used for sample material. A good way to stir up the milk is to pour it
several times out of one vessel into another and back. Before analysis
the samples have to be filtered in order to be free from foreign
fragments. Milk samples should be 5-35 °C. Full cream samples
containing fat over 10% should be heated up to 42-43 °C and then
cooled to 25 – 30 °C. If the sample temperature is over 40 °C the
message “Sample overheated” will appear on the display. Use milk
samples only once and do not return it to the vessel. Samples can be
kept for a maximum of 2 days if they are stored at a temperature not
exceeding 5 °
С
.
Milk stirring
It is a very important condition for receiving exact results. Before
taking samples from big vessels the milk (fresh or thermally treated,
whole-milk or whipped) has to be well stirred for no less than 5 min., by
vertical and circular slow movements. Mixing spoon with long handle is
used, allowing the lowest layers of the liquid to be reached. The milk in
the milk-cans is stirred 5 to 8 times from the surface to the bottom and
reverse with slow circular movements.
Sample preservation
The vessels where the samples will be put have to be clean, dry,
glass, metal or from other suitable material, to be tightly closed with
rubber or other stopples. The stopples not to absorb water and fat and
not to influence the analyses sample content.
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