This International Standard specifies a reference method for the determination of milk fat purity using gas
chromatographic analysis of triglycerides. Both vegetable fats and animal fats such as beef tallow and lard
can be detected. By using defined triglyceride equations, the integrity of milk fat is determined.
Basically, the method applies to bulk milk, or products made thereof, irrespective of feeding, breed or lactation
conditions. In particular, the method is applicable to fat extracted from milk products purporting to contain pure
milk fat with unchanged composition, such as butter, cream, milk, and milk powder.
However, under the circumstances listed hereafter, a false positive result can be obtained. Hence, the method
is not applicable to milk fat:
a) obtained from bovine milk other than cow's milk;
b) obtained from single cows;
c) obtained from cows which received an exceptionally high feeding of pure vegetable oils such as rapeseed
oil;
d) obtained from colostrum;
e) subjected to technological treatment such as removal of cholesterol or fractionation;
f) obtained from skim milk or buttermilk;
g) extracted by using the Gerber, Weibull–Berntrop or Schmid–Bondzynski–Ratzlaff methods, or that has
been isolated using detergents (e.g. the Bureau of Dairy Industries method).
With the extraction methods specified in g), substantial quantities of partial glycerides or phospholipids can
pass into the fat phase. Consequently, the scope of this International Standard excludes certain products and
particularly cheese, whose ripening process can also affect the fat composition to such a degree that a false
positive result is obtained.
BS EN ISO 17678:2010 history
2019BS EN ISO 17678:2019 Milk and milk products. Determination of milk fat purity by gas chromatographic analysis of triglycerides
2010BS EN ISO 17678:2010 Milk and milk products - Determination of milk fat purity by gas chromatographic analysis of triglycerides (Reference method)