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GEA Niro Method No. A 7 a |
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Revised: September 2005 |
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1.
Definition
The content of slowly dispersible
particles in milk powders is the number of particles still not dispersed after
this procedure.
2.
Scope
The method is to be used for
agglomerated milk powder and for all other agglomerated dairy
products.
3.
Principle
The sample is
evenly spread on the surface of water adjusted to a certain temperature
depending on the product. The mixture is stirred manually for a short time and
then filtered through a filter paper.
4.
Apparatus
1. Balance, sensitivity
± 0.01 g.
2. Beaker - 250
ml.
3. Teaspoon, 40 mm high, 29 mm
wide.
4. Filter paper, coarse -
diameter 90 mm.
5. Büchner funnel, filter flask
and water air pump.
6. Standard scale 0-5 (see Fig.
1).
5.
Reagents
None.
6.
Procedure
1. Weigh out the correct amount of powder
± 0.1 g:
Skimmed milk: 10 g
Whole
milk: 13
g
2. Pour 100 ml of tap water, at different
temperatures, into the beaker and add the powder:
Skimmed milk:
; 20°
C
± 2°C
Whole milk:
; 40°
C
± 2°C
Lecithinated whole
milk: 20°C ± 2°
C
3. Using 30 complete circular stirring movements,
stir with the teaspoon for 20 seconds.
4. Allow to stand for 2 minutes.
5. Using 5 complete circular stirring movements, stir
for 3 seconds.
6. Filter through a Büchner
funnel.
7.
Result
Compare with standards (0-5) using
Fig. 1 immediately after filtering.
8.
Reproducibility
N/A
9.
Remarks
A sample classified as being
between two standard discs is always set at the highest value. The sample is
classified as '0' if no white particles are found on the filter
paper.
10.
Literature
·
GEA Niro Research Laboratory
