Amino acids are involved in building proteins, hormones and neurotransmitters. They are vitally important for human health. Accurate labeling of foods and supplements for protein content or individual amino acids is necessary to ensure regulatory compliance. Maria Ofitserova, PhD, Senior Research Chemist at Pickering Laboratories, Inc., discusses common questions about the analysis of amino acids in different matrices.

1 How is the protein content of foods determined for labeling purposes?

For a long time, protein content was estimated based on the analysis of total nitrogen. Unfortunately, this approach is error-prone and unable to catch adulteration, which can be particularly devastating in products such as infant formula. Using analysis of individual amino acids to determine protein content is the most accurate method. It should be used whenever possible, but especially when labeling foods designed to be sole sources of nourishment or which address special dietary conditions.

2 How should the supplements industry approach testing?

Manufacturers of supplements containing proteins and individual amino acids need to test both raw materials and final products to ensure the accuracy of label claims and support industry standards throughout the supply chain. Amino acids should be analyzed by a sensitive, accurate, and robust method. Preferably one that works for wide variety of supplements, naturally derived or synthetic. Choosing the right method guarantees product quality and increases consumer confidence.

3 What are the advantages of amino acids analysis with post-column derivatization?

Amino acids analysis with Ninhydrin post-column derivatization is matrix-independent. The same simple extraction methods, without any additional clean up, and the same analytical conditions can be used for a wide variety of samples. This is especially important for complex samples analyzed without hydrolysis, such as botanicals, supplements, clinical samples, and specialized foods and drinks.

4 What other industries need to analyze amino acids?

The European Pharmacopeia mandates the post-column method for amino acids analysis. It is a method of choice in the pharmaceutical industry for monitoring production processes and quality of recombinant proteins. In addition, analysis in blood and urine samples allows doctors to diagnose and monitor numerous metabolic diseases, including inborn errors of metabolism such as Phenylketonuria and Maple Syrup Urine Disease. This testing is extremely important for every newborn child.

5 How are Pickering Laboratories’ products used in amino acids analysis?

Pickering Laboratories, Inc. manufactures post-column derivatization instruments and the full complement of consumables for amino acids analysis, including columns, reagents, eluants, and calibration standards. Our products are successfully used for the analysis of food and drinks, animal feeds, pharmaceuticals, and clinical samples. We also offer expertise in method development and validation to help our customers implement and efficiently run our methods.