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Reporting cocoa flavanol content in research

As interest in the biomedical properties of flavanols has grown, so has the need for accurate analysis of their properties

scientist testing in lab

Analytics has been fundamental to our cocoa flavanols research program since the 1990s and we have a long-standing commitment to the development of analytical methods for flavanols. This includes partnering with AOAC International, an association that sets standards for methods of food analysis, and National Institute of Standards and Technology, U.S. Dept. of Commerce (NIST) to ensure consistency and reliability in cocoa flavanol reporting.

Developments in analytical methods

Our first analytical research method to quantify cocoa flavanols in foods was published in 1999. Being able to accurately quantify the level of cocoa flavanols is a necessary first step along the path to beginning clinical dietary interventions and examining the effect of cocoa flavanols on human health. Since then, our researchers have made critical advancements in the development of these analytical methods.

While the 1999 method paved the way for clinical dietary intervention and has been used extensively in cocoa flavanol studies, there was room for improvement. In 2012, our researchers established a new, more reliable AOAC First Action Official Methods of Analysis SM (OMA 2012.24). Since then, we've continued to refine our approach.  Leveraging a better HPLC column and a reference material created in partnership with NIST, this latest method addresses key analytical challenges with the prior method and makes important advancements in accuracy and precision. Recognition of the analytical improvements over the prior method is evidenced by the receipt of a new First Action Official Methods of Analysis SM by the AOAC in April 2020 for this updated method (OMA 2020.05). 

The 2020 method also has important consequences for research that features previous methods. Included below are a list of key cocoa flavanol studies and how the reported cocoa flavanol content changes with the newest AOAC method.



Reported cocoa flavanol content

Converted to 2020 First Action Official Method of AnalysisSM (mean ± SD)

Schroeter, H., et al. 

Proc Natl Acad Sci USA, 2006

37 mg

917 mg

30 mg ± 2

760 mg ± 45

Balzer, J., et al. 

J Am Coll Cardiol, 2008

75 mg

371 mg

963 mg

60 mg ± 5

305 mg ± 20

795 mg ± 50

Brickman, A.M., et al. 

Nat Neurosci, 2014

10 mg

900 mg

8 mg ± 1

745 mg ± 45

Mastroiacovo, D., et al. 

Am J Clin Nutr, 2015

48 mg

520 mg

993 mg

40 mg ± 2

430 mg ± 25

820 mg ± 50

Heiss, C., et al. 

Age (Dordr), 2015

0 mg

450 mg

0 mg

370 mg ± 20

Rodriguez-Mateos, A., et al. 

Am J Clin Nutr, 2018

15 mg

560 mg

690 mg

10 mg ± 2

465 mg ± 30

570 mg ± 35


To understand more about what the latest method means for cocoa flavanol content claims, visit our Analytics page. 

An introduction to cocoa flavanols