LABEC M-MIA-LA - Manual (Page 78)

Ultrasonic milkanalyser
Operation manual 04.11.09 76/107
5.1. For cow milk (whole milk, low fat, skimmed milk) and UHT milk
Determination of fat content – Gerber’s method, described in Appendix
Methods.
Density determination – using aerometer, described in Appendix Methods.
SNF determination – by formula – p. 3.2.3.1.B
Determination of Lactose content – by formula – p.3.2.3.2.А
Determination of salts content – by formula – p. 3.2.3.3.А
Total protein content determination – by formula – p. 3.2.3.4.А
Example: Determination of the quality parameters for two samples cow milk
(low fat and high fat), obtained and prepared according p. 2.3.1 and 2.4.1.
First – determine the fat content in the samples, using the Gerber’s method
(p.3.2.)
Suppose that for the first sample the result is 2,0 %F, for the second – 5,9
%F.
Second – determine the milk density, using aerometer (p.3.1.)
Suppose that the results are 1,0316 for the first sample and 1,0274
for the second
Third – Calculate the SNF content using the formula (p.3.2.3.1.B)
Fourth – determine the lactose content by the formula (p.3.2.3.2.А)
Lact. = SNF * 0,55 = 8.50 * 0.55 = 4.67 %
Lact. = SNF * 0,55 = 8.23 * 0.55 = 4.53 %
Fifth – determine the salts content by formula (p.3.2.3.3.А /
Salts = SNF * 0,083 = 8.50 * 0.083 = 0.71 %
Salts = SNF * 0,083 = 8.23 * 0.083 = 0.68 %
Sixth – determine the total protein content by formula (p.3.2.3.4.А)
Proteins = SNF * 0,367 = 8.50 * 0.367 = 3.12 %
Proteins = SNF * 0,367 = 8.23 * 0.367 = 3.02 %
So, when calibrating the milk analyser we’ll use samples with the following
parameters:
I Ist sample
(low fat)
II nd sample
(high fat)
% 50 , 8
378 , 0
0316 , 1 / 100 100 0 , 2 075 , 0
=
− + ∗
=
SNF
% 23 , 8
378 , 0
0274 , 1 / 100 100 9 , 5 075 , 0
=
− + ∗
=
SNF