The protein content is taken to mean the nitrogen content multiplied by the factor 6.25. The nitrogen content must be determined according to ISO method 937-1978.
The water content must be determined according to ISO method 1442-1973.
The extraneous water content is given by the formula: a – 4b, in which:
=
water content,
=
protein content.
The collagen content is taken to mean the hydroxyproline content multiplied by the factor 8. The hydroxyproline content must be determined according to ISO method 3496-1978.
The methods of analysis referred to in this Annex are those applying on the date of entry into force of this Regulation, without prejudice to any subsequent amendment to such methods. They are published by the ISO Secretariat, 1 Rue de Varembé, Geneva, Switzerland.