Based on text provided by Christian G. Krueger Co-Founder and CEO, Complete phytochemical Solutions, LLC

cranberryConcerning problems with adulteration and overall product quality plague the cranberry supplement industry. Some unscrupulous manufacturers are blending other polyphenols, such as grape seed extract, into their cranberry products. Others are marketing products labeled as cranberry when they don’t contain any cranberry constituents.

To save itself – and that’s indeed what needs to happen – cranberry industry stakeholders need to accept responsibility and become more accountable. That means raising the bar on quality standards. Self-regulation is essential.

I am encouraged that reputable companies, such as Fruit d’Or Nutraceuticals, are taking bold steps to deal with the hurdles that threaten the long-term future of the cranberry industry. It is my sincere hope that others in this, and related industries, will follow suit”, wrote (February 2015) Christian Krueger, Director of Operations & Research Program Manager I at the University of Wisconsin, Madison. And co-founder and CEO of Complete Phytochemical Solutions, LLC, an independent, third-party consulting and testing botanical ingredient company.

“The three primary pillars that must be strengthened – authenticity, standardization and efficacy – are inseparable. You can’t address one issue without the other two. Consumers expect manufacturers to deliver on the quantity and quality of an ingredient necessary for the outcome they’re expecting. 

We know, for example, that in relation to urinary tract health the minimum efficacious threshold for cranberry proanthocyanidins (PACs) is 36 mg, the equivalent to one glass of 27% cranberry juice cocktail drink. However this is not consistently being used as the gold standard in product development. Whereas one capsule of Cran Naturelle per day may deliver on the requisite 36 mg of cranberry PACs, other cranberry products may require the consumer to take 20 to 40 capsules daily to reach this threshold. 


One of the biggest issues is understanding the raw ingredients. What’s going into the formulations that consumers are purchasing off store shelves? Ultimately it’s the responsibility of individuals procuring ingredients to understand their product’s composition. If they are being misled at any stage, they need to make better use of the newer tools available to them to ensure their product’s integrity.

To spend money on research without knowing what’s in your product is a fool’s game. We need to level the playing field by learning as much as we can about the starting materials. Much of my work is focused on how the ingredients look and behave in analytical procedures. This deeper understanding makes it easier to identify authenticity, composition and any adulterations. 

Think of this as cranberry forensics. We’re first testing the fruit, and analyzing its unique polyphenol “fingerprint”: the flavonoids, anthocyanins, hydroxycinnamic acids and PACs. When this isn’t done, tracing the end product back to the ingredient is nearly impossible.

Not all cranberry is the same. In the past, most products relied on concentrates made from juice powders. Now we’re adding skins, seeds and pomace. While the berry has fiber, protein, seeds and oils, we use polyphenols as markers. And polyphenols from seed powder, for example, are different than those found in whole cranberry powder. Once we know what’s in the starting ingredients, we have a blueprint for understanding results of all other forensic analyses. 

Thus, running the initial fingerprint analyses and determining the resulting blueprint are essential steps in validating the authenticity of cranberry products.


Most cranberry products are marketed based on their PAC content. We must all guard against those companies that adulterate their products with less expensive PAC sources, such as grape seed extract, to raise the PAC content. These other sources contain PACs that do not have the unique A-type linkages found in cranberry PACs that are necessary to achieve the biological activities associated with cranberry intake.

Many analytics tools can be fooled. Some will just calculate the PAC amount without being able to distinguish between those sourced from grape seed extract and cranberry. This is not sufficient for authenticating an ingredient or product.

But in the last two years, we have developed a number of non-proprietary tools to measure PACs and determine if an ingredient is authentic cranberry. 

These tools are the key to the industry’s future. We need to educate not only buyers and sellers, but also the labs, on how to look at these products’ unique attributes. Most standard specification sheets and certificates of analysis are weak, because they are based on the most inexpensive assays. A deeper dive should always be demanded.  

The development and use of new analytical tools has significantly broadened our foundational understanding of the individual cranberry components. These tools are major breakthroughs for efficacy and authenticity. We are able to understand the matrix of the whole cranberry, and its different components, where we were unable to do so before. Using these valuable tools, dried cranberry juice will behave differently than an all-organic cranberry powder. These differences are reflected in the unique fingerprints of each product type. 

We have isolated the natural cranberry’s PACs. This information is now used as a calibrating method to support mass spectrometry, and to improve the accuracy of standardization and quantification. 

One of the most exciting innovations now available is Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS). This tool authenticates PACs, addressing adulteration issues and allowing product manufacturers to determine shelf-life based on PAC stability.  Its use will ultimately lead to higher consumer confidence. 

These newer analytical tools have been peer reviewed. Manuscripts are accessible to the industry at large. While they require an above-average expertise in phytochemistry, our goal is that the industry will adopt this approach moving forward. 


We need more repeatable studies that use efficacious, standardized products delivered at the appropriate dosage, especially if the cranberry industry is to move beyond the realm of urinary tract health. The forward-thinking and responsible industry players, such as Fruit d’Or Nutraceuticals, are already doing their due diligence. By first understanding the fingerprints of their raw ingredients, they are designing appropriate studies that link composition to outcome. More specifically, these studies are linking the specific and unique structures of cranberry components, such as PACs, to their mechanism of action in biologic systems. Working with companies such as Fruit d’Or Nutraceuticals can give formulators, buyers and distributors increased confidence in their ingredients.

Research suggests that when cranberry is consumed, there is a reduction in the adhesion of certain bacteria in the urinary tract that may help to prevent the initiation of urinary tract infections.  This effect appears to be dependent on the cranberry PAC dose consumed, however it is unclear how the PACs are exerting this effect. There is currently a lack of consensus as to what extent PACs are absorbed in the gut. What is known is that the presence of PACs in the gut allow these compounds to exert biologic effects on the gut epithelium, the gut associated lymphoid tissue and resident microflora. Both soluble (extractable) PACs and insoluble (non-extractable) PACs, those PACs that remain bound within press cake after juicing, are capable of inhibiting extra-intestinal pathogenic Escherichia coli (ExPEC) from invading and colonizing enterocytes. The understanding of mechanisms by which PACs affect ExPEC transient colonization and persistence in the gut serves as a conceptual model to study, in a larger context, how PAC may affect other ExPEC strains and extra-intestinal infections and can explain the potential of cranberry PAC in urinary tract health despite their poor absorption.

Finished product testing is just as important as the quality of the starting raw materials. By starting with high-quality pure raw materials, analytic instruments such as MALDI-TOF MS , will better determine if an end-product has been manipulated or adulterated in any way. 

Next steps 

To strengthen the cranberry industry, we need to raise awareness of the need for better and more extensive analytical testing using the powerful techniques that are now available. Ingredient buyers need to ask more informed questions. The industry also needs to self-regulate label transparency. The fingerprint analysis is creating one level of authentication and standardization that can be communicated directly to consumers. The label should also clearly communicate effective dosages. Just because a product may meet a consumer’s budget does not mean that it will deliver on its stated or implied promises. Hold yourselves to higher labeling standards.