It is customary to call the density of milk the mass of milk at its temperature of 20 ° C, enclosed in a unit of its volume. The density of milk is considered an indicator of its naturalness. To determine it, it is necessary to use special devices.
Milk density concept
According to generally accepted standards, the density of milk is made up of the density of its constituents such as milk fat, lactose, protein and salt. Basically, the density reflects the content of all these components in milk. The density can be used to determine whether the milk has been diluted with water or not.
When determining the density of milk, it is recommended to check the equipment used. We are talking about lacto-density meters, which in terms of accuracy may be completely unsuitable for such measurements. It is also customary to use professional glass hydrometers to determine this characteristic of milk. By the way, this value should be determined no earlier than two hours after milking the cow.
How to determine the density of milk?
To determine the exact density of milk, you will need to prepare a 250 ml measuring cylinder with a diameter of at least 5 cm and a lactodensimeter. You should also find out if the lactodensimeter has been tested in a laboratory of measures and measuring instruments. Be sure to read the results of this check. If everything is in order with the device, you can start measuring the density.
Take the milk prepared for analysis, carefully pour it into the cylinder up to 2/3 of its volume along the wall. At the same time, make sure that no foam forms during pouring. Then take a dry lactodensimeter and dip it into milk. The device must be in a completely free floating state. After about a couple of minutes, the vibrations of the lactodensimeter should stop. This will mean that it is time to read the density and temperature of the milk along the upper edge of the meniscus. In this case, the eye should be at the level of the meniscus line.
Measure twice. Be sure to lightly shake the lactodensimeter and find the arithmetic mean of the two determinations. It is strongly recommended to determine the relative density of milk at its temperature of 20 ° C. If it turned out to be higher, it will be necessary to add 0, 0002 for each degree to the density readings. On the other hand, when the temperature drops, this value must be subtracted. By the way, in GOST there is even a special table of corrections for milk test methods. It turns out that no specific knowledge is required to determine the density of milk. It is enough just to study in detail the sequence of actions.
