Whether test methods are used for research or finished products, knowing exactly what’s in starting cranberry materials and what you are looking to test are essential and imperative. For example, what is the percentage and volume of proanthocyanidins (PACs) found in whole fruit cranberry powder? Are they insoluble, soluble or both? To measure the amounts and types of bioactives in its cranberry ingredients, Fruit d’Or uses only the most technically advanced, reliable tests available: DMAC and butanol for measuring and testing for soluble and insoluble PACs.

“Accurate quantification of bioactive compounds, along with consistency, are critical factors that companies look for when selecting a supplier of quality cranberry (Vaccinium macrocarpon Ait.) ingredients,” agrees Complete Phytochemical Solutions CEO Christian Krueger, who has introduced breakthrough test methods for measuring cranberry’s soluble and insoluble proanthocyanidins PACs and has also developed new reference standards such as C-PAC.

“The ‘A-type’ proanthocyanidins (PAC) in cranberry fruit are the bioactive components that have been linked to improved urinary tract health, oral health and gut health.”

What are the best analytic methods for accurate quantification of PACs?

For many years, companies have been using the wrong test methods and reference standards to measure soluble and insoluble PACs in cranberry powders. Evidence shows that Euro Phrama and HPLC are not reliable test methods to measure PACs. Both these test methods lead to inaccurate results that are misleading for the industry. There are now new test methods and new research available to demonstrate more accurate, consistent  and reliable test results for both soluble and insoluble PACs found in cranberry juice powder and whole fruit powders. These new test methods are known as the DMAC and Butanol.   

“The 4-(dimethylamino) cinnamaldehyde (DMAC) assay is the preferred method for quantification of soluble (extractable) PAC,” says Krueger. “This method was included in the 2016 American Herbal Pharmacopeia cranberry monograph, a guidance document for standards of analysis and quality control. A detailed discussion on the advantages of the DMAC method can be found in the publication by Krueger et al.

Because whole-fruit cranberry powder contains both soluble and insoluble PACs, a relative new test is recommended: butanol-hydrochloric acid (BuOH). “The butanol-hydrochloric acid (BuOH) is the preferred method for the quantification of insoluble (non-extractable) PAC. This method was recently adopted by the Cranberry Institute to support the specifications of the standardized research material (a freeze-dried whole-cranberry powder) that is made available to health researchers. The butanol test method will not work on cranberry juice powders because there are no insoluble PACs found in cranberry juice powders or cranberry cocktail juice. The butanol test method is relatively new to the cranberry industry. Many companies and laboratories still need to learn how important this test method is and how it can help generate greater sales.”    

By quantifying cranberry ingredients’ insoluble PACs, the butanol test method will now open up doors to new research and science to take cranberry beyond UTIs and to areas such as gut health.



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