North America’s last animal test requirement for food labels faces disruption from new protein digestibility methods

Written by Dr Wendelyn Jones, PhD

We all know we have to eat protein to be healthy and functional. But did you know that at present, protein remains the only nutrient for which the use of an animal test is still required to make claims about protein content on North American foods? For many protein ingredients, existing databases can be used, but data are limited for new protein ingredients or if you want to account for how processing affects the final food product. With the help of a team of scientists, that may be changing.

Digestiblity, along with the amino acid profile, are necessary to adjust protein levels to reflect protein quality overall. Researchers have been working hard to develop alternatives to measure protein digestibility in ways that could promote innovation in protein-rich Canadian and US foods. Together with public health efforts to increase the consumption of plant-based foods, removing hurdles provides incentives for the food industry to consider protein quality when developing foods as well as in claiming protein content on product labels.

Should governments adopt the researchers’ validated non-animal alternatives – called in vitro methods – to measure protein quality, a new era for protein claims and marketing could emerge for food products. In the meantime, product developers can use this tool for screening ingredients and processing effects in order to develop products with high protein quality.

Definitions

The definition of protein quality has historically been based on the ability of dietary protein to provide sufficient amounts of essential amino acids to support growth in living animal models. Protein content claims in the US and Canada (but not in many other countries) for consumer foods require information determined through the use of animal tests – called in vivo methods – to assess the quality of the protein. A method called PDCAAS can be used in both the US and Canada to calculating protein quality. This method takes into account both the protein’s digestibility as well as the amino acids present.

Testing alternatives

Now, in a recent paper, a team of scientists supported by IAFNS Protein Committee addresses the strong rationale for approving in vitro methods to determine the digestibility component needed for adjusting grams of protein to take into account overall protein quality. The team reports that a collaborative study is ongoing that will evaluate the proficiency of alternative in vitro methods to measure protein digestibility.

To advance this issue, researchers need to specify methods and then collect data from across multiple labs in order to gain approval from a credible certifying body. The result will be one or more standardized methods of analysis for determining protein digestion using in vitro methods. Standardized analytic methods recognized by credible organizations is critical to the potential future recognition of these methods by regulatory agencies such as Health Canada and the US FDA.

The article briefly summarizes the state-of-the-science in the field, to inform the research community of next steps, and to describe the path engaging collaborative laboratories in a proficiency test as the first step in moving forward toward acceptance of non-animal, in vitro digestibility methods.

Throughout, a consultative and iterative process is being utilized to ensure the program goals are met. Success will be achieved when the proposed path results in the acceptance of in vitro methods for protein digestibility determinations, which will enable increased protein analyses and improved nutrition labeling of protein foods.

Positioning protein tests

In order to position an in vitro protein method to both Health Canada and the U.S. FDA as being suitable for food labeling, it must have a standardized method of analysis approved by an accrediting body. Such bodies include the Association of Official Analytical Collaboration (AOAC), the International Organization for Standardization (ISO) and the American Oil Chemists' Society (AOCS).

The AOCS Uniform Methods Committee approved the in vitro methods as standard methods on March 6, 2025, including AOCS Methods Ka 1a (pH-stat) and Ka 1b (pH-drop). The next step is to share the validated methods to regulatory bodies such as the U.S. FDA and Health Canada for consideration as methods acceptable for calculating PDCAAS.

In the meantime, ingredient and food manufacturers can use these methods as screening tools to assess effects of ingredients and processing during the product development process. This advancement reduces the ethical burden associated with protein testing but also serves as an incentive for innovation in the development of high-quality, plant-based, and alternative-protein foods. Product developers can run tests comparing multiple ingredients and processing conditions in order to select the combination delivering relatively higher protein quality. In the past, data was limited or even not available to run such screening tests.

An important concept in developing key methods of analyses is 'fit for purpose'. The degree of accuracy and precision required for a measure of protein digestibility to enable a food product for the general public to carry a protein content claim must be such that it prevents overestimation of protein content.

Another key consideration for advancing the new alternative methods is the establishment of data across a number of test protein sources. The choice of protein food samples was critical for this evaluation to ensure applicability over a wide range of foods and food forms, including plant, animal and novel protein sources.

Ongoing consultation

During the course of this work and as mentioned above, consultation with the approving body AOCS and representatives at Health Canada is ongoing. A careful assessment was undertaken before conducting research in order to understand what was needed to achieve regulatory acceptance of in vitro methods in calculating protein quality using the PDCAAS method.

A two-step process was used: Step 1 established standardized methods of analysis by a credible body based on valid science; Step 2 is seeking acceptance by regulatory bodies. The final result can be greater consumer transparency around protein content on innovative new foods across North America while reducing reliance on test animals.

Dr Wendelyn Jones is Executive Director of the Institute for the Advancement of Food & Nutrition Sciences. She has a strong scientific background in the food, agriculture and chemical industries, and brings over 20 years of global experience in industry and government. She works with IAFNS’s multi-sector scientists, trustees and staff to extend the organization’s contribution to and impact within diverse scientific and health communities