Appendix Freezing Point Determination - Milkotester Master Pro Operating Instructions Manual

Appendix Freezing point determination

1. Methods for determination.
The milk analyzer determines the freezing point of each sample and
the quantity of added water. The milk analyzer does not measure the
freezing point, but calculates it from the components it depends on. The
basic components in the milk are water, salts, lactose, FAT, proteins,
minerals (salts) and acids. The freezing point depends only on the diluted
in the milk components and quantity of the solvent (in the milk it is water).
The ultrasonic technology allows direct measurement of FAT, proteins,
lactose + salts (the soluble components, only influencing the freezing
point), and the quantity of the solvent in % is determined by 100 % – total
solids %, total solids = lactose % + FAT % + proteins % + salts % + acids
%.
Without understanding the meaning of the freezing point – determined or
shown from the milk analyzer added water result easily may lead to a
mistake for the value of this parameter.
2. The basic freezing point.
Milk freezes at lower temperature than water. The average freezing
point of the raw milk in the most regions is at about -0,540°С. The average
reading for your region is called "basic" freezing point.
The freezing point of milk is a "physiological constant". This does not
mean that it will not vary. In fact feed, breed, season, time of lactation,
climate, whether the sample is taken at the beginning, middle or end of
lactation – all these factors will have an effect on the freezing point of the
individual sample. This means that there is an average value of all these
numbers. The more samples used in obtaining this average, the more
reliable it is as a base. Or the basic freezing point is an average of
freezing points of milk, taken from many cows. When a laboratory checks
a producer, it is only comparing the average of the producer's cows
against a larger area average.
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Operating Instructions Master Pro
Milkotester Ltd
Ultrasonic milk analyzers