§ 172.320 Amino acids.
The food additive amino acids may be safely used as nutrients added to foods in accordance with the following conditions:
（a） The food additive consists of one or more of the following inpidual amino acids in the free, hydrated or anhydrous form or as the hydrochloride, sodium or potassium salts:
L-Alanine
L-Arginine
L-Asparagine
L-Aspartic acid
L-Cysteine
L-Cystine
L-Glutamic acid
L-Glutamine
Aminoacetic acid （glycine）
L-Histidine
L-Isoleucine
L-Leucine
L-Lysine
DL-Methionine （not for infant foods）
L-Methionine
L-Phenylalanine
L-Proline
L-Serine
L-Threonine
L-Tryptophan
L-Tyrosine
L-Valine
（b） The food additive meets the following specifications:
（1） As found in “Food Chemicals Codex,” National Academy of Sciences/National Research Council （NAS/NRC）, 3d Ed. （1981）, which is incorporated by reference （Copies may be obtained from the National Academy Press, 2101 Constitution Ave. NW., Washington, DC 20418, or may be examined at the National Archives and Records Administration （NARA）. For information on the availability of this material at NARA, call 202–741–6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. ） for the following:
L-Alanine
L-Arginine
L-Arginine Monohydrochloride
L-Cysteine Monohydrochloride
L-Cystine
Aminoacetic acid （glycine）
L-Leucine
DL-Methionine
L-Methionine
L-Tryptophan
L-Phenylalanine
L-Proline
L-Serine
L-Threonine
Glutamic Acid Hydrochloride
L-Isoleucine
L-Lysine Monohydrochloride
Monopotassium L -glutamate
L-Tyrosine
L-Valine
（2） As found in “Specifications and Criteria for Biochemical Compounds,” NAS/NRC Publication, 3rd Ed. （1972）, which is incorporated by reference （Copies are available from the Center for Food Safety and Applied Nutrition （HFS–200）, Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740, or available for inspection at the National Archives and Records Administration （NARA）. For information on the availability of this material at NARA, call 202–741–6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. ） for the following:
L-Asparagine
L-Aspartic acid
L-Glutamine
L-Histidine
（c） The additive（s） is used or intended for use to significantly improve the biological quality of the total protein in a food containing naturally occurring primarily-intact protein that is considered a significant dietary protein source, provided that:
（1） A reasonable daily adult intake of the finished food furnishes at least 6.5 grams of naturally occurring primarily intact protein （based upon 10 percent of the daily allowance for the “reference” adult male recommended by the National Academy of Sciences in “Recommended Dietary Allowances,” NAS Publication No. 1694, 7th Ed. （1968）, which is incorporated by reference. Copies are available from the Center for Food Safety and Applied Nutrition （HFS–200）, Food and Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740, or available for inspection at the National Archives and Records Administration （NARA）. For information on the availability of this material at NARA, call 202–741–6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
（2） The additive（s） results in a protein efficiency ratio （PER） of protein in the finished ready-to-eat food equivalent to casein as determined by the method specified in paragraph （d） of this section.
（3） Each amino acid （or combination of the minimum number necessary to achieve a statistically significant increase） added results in a statistically significant increase in the PER as determined by the method described in paragraph （d） of this section. The minimum amount of the amino acid（s） to achieve the desired effect must be used and the increase in PER over the primarily-intact naturally occurring protein in the food must be substantiated as a statistically significant difference with at least a probability （P） value of less than 0.05.
（4） The amount of the additive added for nutritive purposes plus the amount naturally present in free and combined （as protein） form does not exceed the following levels of amino acids expressed as percent by weight of the total protein of the finished food:
| Percent by weight of total protein (expressed as free amino acid) | |
| L-Alanine | 6.1 |
| L-Arginine | 6.6 |
| L-Aspartic acid (including L-asparagine) | 7.0 |
| L-Cystine (including L-cysteine) | 2.3 |
| L-Glutamic acid (including L-glutamine) | 12.4 |
| Aminoacetic acid (glycine) | 3.5 |
| L-Histidine | 2.4 |
| L-Isoleucine | 6.6 |
| L-Leucine | 8.8 |
| L-Lysine | 6.4 |
| L- and DL-Methionine | 3.1 |
| L-Phenylalanine | 5.8 |
| L-Proline | 4.2 |
| L-Serine | 8.4 |
| L-Threonine | 5.0 |
| L-Tryptophan | 1.6 |
| L-Tyrosine | 4.3 |
| L-Valine | 7.4 |
（d） Compliance with the limitations concerning PER under paragraph （c） of this section shall be determined by the method described in sections 43.212–43.216, “Official Methods of Analysis of the Association of Official Analytical Chemists,” 13th Ed. （1980）, which is incorporated by reference. Copies may be obtained from the AOAC INTERNATIONAL, 481 North Frederick Ave., suite 500, Gaithersburg, MD 20877, or may be examined at the National Archives and Records Administration （NARA）. For information on the availability of this material at NARA, call 202–741–6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. Each manufacturer or person employing the additive（s） under the provisions of this section shall keep and maintain throughout the period of his use of the additive（s） and for a minimum of 3 years thereafter, records of the tests required by this paragraph and other records required to assure effectiveness and compliance with this regulation and shall make such records available upon request at all reasonable hours by any officer or employee of the Food and Drug Administration, or any other officer or employee acting on behalf of the Secretary of Health and Human Services and shall permit such officer or employee to conduct such inventories of raw and finished materials on hand as he deems necessary and otherwise to check the correctness of such records.
（e） To assure safe use of the additive, the label and labeling of the additive and any premix thereof shall bear, in addition to the other information required by the Act, the following:
（1） The name of the amino acid（s） contained therein including the specific optical and chemical form.
（2） The amounts of each amino acid contained in any mixture.
（3） Adequate directions for use to provide a finished food meeting the limitations prescribed by paragraph （c） of this section.
（f） The food additive amino acids added as nutrients to special dietary foods that are intended for use solely under medical supervision to meet nutritional requirements in specific medical conditions and comply with the requirements of part 105 of this chapter are exempt from the limitations in paragraphs （c） and （d） of this section and may be used in such foods at levels not to exceed good manufacturing practices.
[42 FR 14491, Mar. 15, 1977; 42 FR 56728, Oct. 28, 1977, as amended at 47 FR 11836, Mar. 19, 1982; 49 FR 10104, Mar. 19, 1984; 54 FR 24897, June 12, 1989; 59 FR 14550, Mar. 29, 1994; 61 FR 14480, Apr. 2, 1996]
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