Protein Testing at Medallion Labs: Ensuring Accurate Labeling and Claims

Accurate protein testing is crucial for food products and nutritional supplements to comply with U.S. Food and Drug Administration (FDA) labeling requirements. Protein content has become a key selling point, especially for products targeting athletes and fitness enthusiasts. This popularity has led to practices like "amino spiking," where manufacturers mislead consumers about a product's true protein content.

Understanding protein testing and its implications for package claims and nutritional labeling is essential. This article explores the protein testing options offered by Medallion Labs, providing insights into protein classification by the FDA and the various testing methodologies available.

Why is Protein Testing Important?

• Regulatory Compliance: Accurate protein testing ensures compliance with FDA labeling regulations.
• Consumer Trust: Honest and accurate labeling builds trust with consumers who rely on protein content for their dietary needs.
• Product Quality: Protein testing helps maintain product quality and ensures that products meet the expected nutritional standards.
• Competitive Advantage: Accurate protein claims can provide a competitive advantage in the market, attracting health-conscious consumers.

How the FDA Classifies Protein

The FDA classifies protein as a nutrient and categorizes it as either Class I or Class II, depending on its presence in a product.

• Class I Nutrients: These are nutrients added to fortified or fabricated foods, including vitamins, minerals, protein, dietary fiber, or potassium. Class I nutrients must be present at 100% or more of the value declared on the label. The nutrient content identified by laboratory analysis must be at least equal to the label value.
• Class II Nutrients: These are nutrients that occur naturally in a food product, such as vitamins, minerals, protein, total carbohydrate, dietary fiber, other carbohydrates, polyunsaturated and monounsaturated fat, or potassium. Class II nutrients must be present at 80% or more of the value declared on the label.

Protein Testing Options at Medallion Labs

Medallion Labs offers a comprehensive suite of protein tests, grouped into several testing categories. The choice of test depends on the client's specific needs and the factors that may influence results. The Protein Dumas test is an FDA-recognized method and is often used as the default method for nutrition facts panels.

Here's an overview of the protein testing options available:

1. Testing for "True" Protein

• Amino Acid Profile Test – Acid Hydrolyzed Amino Acids: This test involves acid digestion followed by ion-exchange chromatography. Results are reported as "Hydrolyzed Amino Acids as Dehydrates," indicating that the values do not include the molecular weight of water. Hydrated amino acid values can be provided upon request. Note that Cystine, Methionine, and Tryptophan are not detected by this method.
• Amino Acid Profile Test – Base Hydrolyzed Amino Acids (Tryptophan): This test uses alkaline digestion and reverse-phase chromatography to determine Tryptophan content. Results are reported as "Tryptophan as Dehydrate," and hydrated tryptophan values can be provided upon request.
• Amino Acid Profile Test – Performic Acid Oxidation Amino Acids (Cystine and Methionine): This test involves performic oxidation and quantification through ion-exchange chromatography. Results are reported as "Performic Amino Acids as Dehydrates," and hydrated amino acid values can be provided upon request.

2. Testing for Animal-Based Sample Matrices

• Amino Acid Profile Test – Hydroxyproline (Collagen): This test uses acid digestion and ion-exchange chromatography. Collagen content is calculated using the results from Hydroxyproline.

3. Testing for Amino Acids Not Bound in a Protein

• Amino Acid Profile Test – Physiologically Free Amino Acids (with Tryptophan): This test measures free amino acids, including Tryptophan. Contact Medallion Labs for specific method details. Results are reported as "Free Amino Acids as Hydrates."
• Amino Acid Profile Test – Physiologically Free Amino Acids (without Tryptophan): This test measures free amino acids, excluding Tryptophan. If Free Tryptophan measurement is needed, the "with Tryptophan" option should be selected. Results are reported as "Free Amino Acids as Hydrates."

4. Testing to Measure Digestibility and Amino Acid Score

• PDCAAS – Invitro (Protein Quality) Test: While not FDA-approved for claims, this test is useful for ingredient comparison, estimating final product claims, checking formulation, and indicating processing effects. The test measures amino acid composition, simulates human digestion, and determines digestibility. The Protein Digestibility Corrected Amino Acid Score (PDCAAS) is calculated, and the following values are reported:
  • Full amino acid profile
  • First limiting amino acid
  • Sample moisture
  • Total protein (by AAA and combustion nitrogen)
  • Animal safe digestibility
  • Amino acid score

5. Testing for Labeling

• Protein (Dumas) Test: This test involves complete combustion of the sample at high temperatures in the presence of pure oxygen. Combustion products are processed to remove water vapor, oxygen, and CO2. NOx is reduced to N2, which is then quantified using a thermal conductivity detector. Protein content is calculated from the nitrogen content using a published conversion factor.
  Available protein factors:
  • 6.25 – general-purpose food products/ingredients (default)
  • 5.70 – wheat, wheat flour, and wheat flour bread
  • 6.38 – dairy
  • 5.46 – peanuts and brazil nuts
  • 5.18 – almonds
  • 5.30 – other tree nuts (coconuts, butternuts, cashews, chestnuts, hazelnuts, hickory nuts, pistachios, walnuts, and pecans)

Selecting the Right Protein Testing Method

Choosing the appropriate protein testing method is crucial for accurate and reliable results. Consider the following factors when selecting a test:

• Regulatory Requirements: Ensure the chosen method complies with FDA labeling requirements.
• Product Matrix: Different food matrices may require specific testing methods.
• Specific Amino Acids: If specific amino acids are of interest, choose a test that accurately measures those amino acids.
• Testing Budget: Balance the need for accurate results with cost-effectiveness.

Ensuring Accurate Protein Testing for Labeling

Medallion Labs offers a variety of protein testing options, all with reliable results. This breadth of offering provides you with the testing method you deem best for your product or nutritional supplement. You pick the method; we deliver results that can be the foundation for label claims or nutrition information labeling requirements. Our breadth of testing options also helps you maximize your testing budget by providing the results you seek in a cost-efficient manner.

Medallion Labs is ready to use our testing options, expertise, and skills for your protein testing. Connect with us or call 1-800-245-5615 to discuss the criteria and testing needs for your food products.