First Commission Directive of 25 October 1985 on methods of analysis for edible caseins and caseinates (85/503/EEC)

7. EXPRESSION OF RESULTS U.K.

7.1. Formula and method of calculation U.K.

The protein content of the sample, expressed as a percentage by mass, is given by:

where:

V₁

is the volume, in millilitres, of the standard volumetric hydrochloric acid solution (4.7) used in the determination (6.5);

V₂

is the volume, in millilitres, of the standard volumetric hydrochloric acid solution (4.7) used in the blank test (6.3);

T

is the strength of the standard volumetric hydrochloric acid solution (4.7) in mol/1;

m

is the mass, in grams, of the test portion.

Calculate the protein content to the nearest 0,1 %.

7.2. Repeatability U.K.

The difference between the results of two determinations carried out simultaneously or in rapid succession on the same sample, by the same analyst under the same conditions shall not exceed 0,5 grams of protein per 100 grams of product.

This repeatability interval should be achieved in 95 % of the times that the method is correctly carried out.