DIAAS Protein Quality Presentation

Originally Published: September 8, 2014
Last Updated: March 12, 2021

“DIAAS Protein Quality” was presented at the 2014 Protein Trends & Technologies Seminar by Joyce Boye, Ph.D., ‎Research Scientist, Agriculture and Agri-Food Canada.

Abstract: From food scientists selecting protein ingredients for optimal label claims to international decision makers determining which foods fit best into a sustainable food supply for the planet’s growing population, FAO’s proposed new method for scoring protein quality will likely have far reaching effects. This presentation provided an overview of the current PDCAAS and proposed DIASS methods for quantifying protein quality and reviewed the possibility of adoption by agri-food industries and regulatory agencies such as the U.S. FDA for labeling and other purposes. Examples of how to determine ingredient combinations for the most complete amino acid profiles and strongest label claims using both PDCAAS and DIAAS were given.

Excerpt from the written summary of this presentation: The Expert Consultation group recommended that the Digestible Indispensable Amino Acid Score, or DIAAS, be adopted to replace PDCAAS. Percent DIAAS may be defined as follows. DIAAS % = 100 x [(mg of digestible dietary IAA in 1g of the dietary protein)/(mg of the same dietary IAA in 1g of the reference protein)]. The values are calculated for each indispensable amino acid (IAA) and the lowest value is designated as the DIAAS.

There are, however, challenges that must be addressed with DIAAS. One of these is the method to determine true ileal digestibility and the current dearth of data on this all-important factor. In the interim, options include utilizing protein digestibility as an equivalent for amino acid digestibility; and if true ileal protein digestibility values are unavailable, utilizing true fecal protein digestibility as a substitute; and using protein digestibility to calculate digestible individual amino acids.

Click here to view the written summary “How will the World Measure Protein Quality?” of this presentation.

Click on the button below to download a PDF of Boye’s PowerPoint presentation “DIAAS Protein Quality.”


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