"Concentrations of amino acids in the sample are calculated using the molecular weight of each individual amino acid minus the molecular weight of water per the recommendations of FAO/WHO expert committees. The above results are recommended for research and product development use. At this time, it is recommended to use in vivo PDCAAS (with rat digestion) for final product labelling unless animal testing is not allowed by the food manufacturer."
This note is included in the product literature because sometimes amino acids are calculated without removal of the molecular weight of water. For the PDCAAS calculation it is removed based on the recommendations of FAO/WHO expert committees.
When the amino acids are calculated, part of that calculation involves the individual molecular weight of the amino acids. The molecular weight of water is removed from this as the water is only added when the amino acid is hydrolyzed from the protein