How is the amount of crude protein measured ?
The Food and Agriculture Organization of the United Nations ( FAO ) recommends that only amino acid analysis be used to determine protein in , " inter alia " , foods used as the sole source of nourishment , such as infant formula , but also provides : " When data on amino acids analyses are not available , determination of protein based on total N content by Kjeldahl ( AOAC , 2000 ) or similar method ... is considered acceptable .