Phenylalanine Content Estimation

The following pages provide various calculators to obtain an upper bound and a lower bound for the phenylalanine (Phe) content of one serving of a food based on the protein content listed in the Nutrition Facts Label.
Warning : For research purpose only. The results obtained with this tool may be inconsistent with the actual Phe content of the food. Neither the authors nor Purdue University assumes responsibility for damages resulting from using this Phe estimation tool.


Protein multiplier method

This method uses the phe:protein ratio multipliers of common foods and the rounded protein content printed on the food label to produce an estimate of the phenylalanine content. Foods containing high Phe like aspertame are identified and rejected.

Please see the method description for more details.

Phe:protein ratio ingredients method

This method helps in refining the Phe estimate range by using a previously constructed database of phe:protein ratio along with the food's ingredient list.

Please see the Step 2 in the method description for more details.

Inverse recipe method

This method involves a numerical optimization based on the ordered ingredient list and the nutrition facts. The nutrition information for at least some of the ingredients is obtained from an existing food database. The result of optimization is valid when no part of any ingredient is removed during the preparation process. And care must be taken to enter the ingredients in the decreasing order of their amounts in serving.

Please see the Step 3 in the method description for more details.