AOAC SPIFAN Stakeholder Panel Meeting Book (March 14, 2019)

• One Comment received: ‘’Specifically, taurine is not a proteinogenic amino acid and is therefore only found free. The table in the SMPR should give taurine an “a” suffix to indicate that it is “determined only as free amino acids. We also note that in a hydrolysate the peak is very small compared to the other amino acids. Surely, in this case then accuracy/ specificity can be readily compromised. If tryptophan requires a separate SMPR and method, why not taurine?’’

Response to Comment (PH) • Tryptophan did not require a separate SMPR, we just left the previous SMPR intact for tryptophan since the MLT was in progress. • As taurine is present in a lower level, it benefits from the more relaxed criteria noted in the SMPR for lower levels of amino acids. • While taurine is not typically thought of as being a proteinaceous amino acid, total taurine methods are already published in the literature that are sometimes stated to recover taurine from peptides (AOAC 999.12 for example).