LABORATORY CATALOGUE for milk analysis - Labochema

3.5 ... in buttermilk (Mohr and Baur’s modification)
The butyrometer is filled with 10 ml of sulphuric acid (density: 1.830 +/- 0.003 g/ml).
Instead of 10.75 ml, 10 ml of buttermilk and 2.0 ml of amyl alcohol are pipetted in. After
sealing, the butyrometer is shaken and immediately centrifuged for 10 minutes. This
prevents annoying blockages. The reading is taken after tempering the specimen at 65°C
+/- 2°C. Fat content = read-off value x 1.075.
3.6 ... in powdered milk according to Teichert’s method
Use of powdered milk butyrometer according to Teichert’s method.
The butyrometer is filled with 10 ml of sulphuric acid (density: 1.818 +/- 0.003 g/ml). 7.5 ml
of water and 1 ml of amyl alcohol are layered onto it. 2.5 g of powdered milk are weighed in a
weighing boat and transferred into the butyrometer through a funnel, using a hair brush. After
sealing, the butyrometer is thoroughly shaken, and intermittently placed in a 65°C water
bath several times. It is centrifuged twice, 5 minutes each time, in the heated centrifuge and
the value is read off after the butyrometer is placed in the water bath for 5 minutes.
3.7 ... in cream acc. to Roeder’s meth. (weighing meth.)
Use of cream butyrometer according to Roeder’s method.
5 g of cream are weighed out into the glass beaker situated in the stopper and transferred
into the butyrometer. Sulphuric acid (density: 1.522 +/- 0.005 g/ml) is poured through the
upper opening of the butyrometer until it reaches just over the upper edge of the glass
beaker. After sealing, the butyrometer is placed in a 70°C water bath and shaken repeatedly
until the protein is completely dissolved. Sulphuric acid is poured in until it reaches
the beginning of the scale, 1 ml of amyl alcohol is added and the butyrometer is sealed,
shaken, and placed in the 70°C water bath for another 5 minutes. Then, it is centrifuged
for 5 minutes and tempered in a 65°C water bath. The reading is taken at 65°C, the fat
column adjusted to the zero point, the value read off at the lower meniscus.
3.8 ... in cream acc. to Schulz-Kley’s meth. (weighing meth.)
Use of cream butyrometer according to Schulz-Kley’s method.
10 ml of sulphuric acid (density: 1.818 +/- 0.003 g/ml), 5 ml of water, ca. 5 g of cream
measured by differential weighing using a syringe or weighing pipette attached to the
scale, and 1 ml of amyl alcohol are successively introduced into the butyrometer. After
sealing, the contents are mixed by shaking and turning the butyrometer upside down
and centrifuged for 5 minutes in the heated centrifuge. The value is read off after 5
minutes of tempering in a 65°C water bath. Note: do not allow more than 15 minutes
to pass between adding the water and shaking the specimen due to the possibility of
a decrease in the heat of reaction as a result of the addition of water. The dissolution
process must be completed within 60 seconds.
Fat content = read-off value x 5 / cream net weight.
3.9 ... in cream acc. to Koehler’s meth. (measuring meth.)
Use of cream butyrometer according to Koehler’s method.
10 ml of sulphuric acid (density: 1.818 +/- 0.003 g/ml), 5.05 ml of cream, 5 ml of water,
and 1 ml of amyl alcohol are poured in turn into the cream butyrometer. When using a
cream syringe, it must be rinsed several times with water before the 5 ml of water are
introduced. The butyrometer is sealed, shaken, centrifuged for 5 minutes, and then the
value is read off after tempering the specimen in a 65°C water bath. The value is read
off from the zero point.
Laboratory catalogue for milk analysis
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