Polyphenol may not lead headlines in major media outlets the way antioxidants and omega-3s do; but, readers who dig deeper into articles can find such language as, the active polyphenol found in green tea, polyphenol-rich chocolate consumption can and Quercetin, a polyphenol derived principally from apple skins. The term isnt completely foreign to consumers, and it only takes a few sentences to explain how polyphenols are plant compounds found abundantly in fruits and vegetables to get consumers to connect polyphenol-fortified products to health benefits.

Polyphenols have very strong consumer recognitionin fact, the term polyphenols itself is gaining recognition on labels, said Jeff Wuagneux, CEO/president, RFI LLC. On top of that, he added product manufacturers are interested in polyphenol products because, They are easy to formulate with and have well-established health benefits.

Polyphenols are useful in a variety of formulations due to their health benefits, according to Christian Artaria, marketing director and head of functional food development, Indena S.p.A. Epidemiological studies, associated meta-analyses and several double blind, placebo-controlled studies strongly suggest long-term consumption of diets rich in plant polyphenols offer protection against development of different pathologies including cancers, cardiovascular disease (CVD), diabetes, osteoporosis and neurodegenerative diseases. Researchers are not only becoming more aware of the range of benefits these compounds provide, but also are uncovering the knowledge related to specific polyphenols for a specific health concern.

Like antioxidants and omega-3s, polyphenols is a huge category, and formulators must focus on a specific polyphenol to produce a specific health effect. Polyphenols break down into two basic categories: flavonoids and non-flavonoids; each of these can be further broken down. Anthocyanins, for instance, are flavonoids that give many berries their red, purple and blue colors, and more than 300 structurally distinct anthocyanins have been identified. Catechins, the polyphenol flavonoids found in tea, include gallocatechin, epicatechin, epigallocatechin, epicatechin 3-gallate and epigallocatechin 3-gallate (EGCG). Ellagic acid is a non-flavonoid found in raspberries, strawberries, cranberries, pomegranates and some nuts. Flavanones, such as hesperetin, naringenin and eriodictyol, and flavones, such as luteolin and apigenin, are found in citrus. Flavonols, which include quercetin, kaempferol, myricetin and isorhamnetin, are found in onions, apples, kale and broccoli. Isoflavones, primarily found in soy, include daidzein and genistein. Proanthocyanidins are polymer chains of flavonoids found in grape seeds and skins, peanut skins and pine bark. And curcuminoids are polyphenols found in the botanical turmeric.

Bioavailability

Each polyphenol mentioned above as well as others can be formulated into numerous products, but the biggest question when it comes to finished goods is whether the plant compounds can actually convey their benefits to the consumer. By using a polyphenol product, you are seeking to deliver a bioactive form of it to induce a health benefit; unfortunately, polyphenols are poorly absorbed, said Dan Lifton, vice president, Maypro Industries. Studies have shown polyphenols are notoriously poorly absorbed. The first challenge is finding a polyphenol that has clinically proven absorption in the body.

Bioavailability differs greatly from one polyphenol to another, according to researchers at the National Institute for Agricultural Research (INRA), a public research institution in France. In a study, INRA researchers reviewed data on 18 major polyphenols from 97 studies that investigated polyphenol absorption among adults after ingestion of a single dose provided as pure compound, plant extract or whole food/beverage.¹ The plasma concentrations of total metabolites ranged from 0 to 4 mumol/L with an intake of 50 mg equivalents, and the relative urinary excretion ranged from 0.3 percent to 43 percent of the ingested dose, depending on the polyphenol. Gallic acid and isoflavones were absorbed the most, followed by catechins, flavanones and quercetin glucosides. The least-absorbed polyphenols were proanthocyanidins, galloylated tea catechins and anthocyanins.

Even in the high end of absorption found in that study, 43 percent is not that high. This means many formulators need to either manufacture products in a way that boosts bioavailability or make sure overages account for the poor assimilation. Artaria noted Indena addresses this issue with its proprietary Phytosome® technology, which is used in its Leucoselect® Phytosome (proanthocyanins from grape seeds), Meriva® (curcuminoids from turmeric) and Siliphos® (silybin from milk thistle) ingredients. Phytosome combines polyphenols with phosphatidylcholine; studies have shown it increases bioavailability compared to polyphenols ingested alone.^2,3

One reason polyphenols are not well absorbed may be due to their large size. This theory posits that the long-chain molecules found in polyphenols and other antioxidants carry a heavy molecular weight, making them too big to be absorbed into the blood from the intestines. Lifton said Maypro tackled this issue with its lychee extract Oligonol®. Maypro takes lychee extract and uses a patented process to reduce the polymer size of the compound so that the percentage of short-chain polymers, namely, monomers, dimers and trimers, become significantly higher than the long-chain polymers, he said. The result of that is a significant enhancement of bioavailability, which has been tested in a clinical study.

Lifton noted manufacturers can also choose a form that heightens bioavailability. One of the interesting things we found out about Oligonol is that its bioavailability doubles when its in a liquid versus when its delivered in a powder, he said. We feel a beverage or a powder that is dissolved in water is better application because it allows you to cut back on the dosage and, therefore, cut back on the cost.

On the flip side, Administration of polyphenols without a food matrix could markedly affect their bioavailability, said Katherine Bond, director of business development, Cyvex. This suggests the consumption of any food may limit polyphenol absorption, and high plasma concentrations would be obtained only if supplements were taken separately from meals. So for the future, the focus should be formulating with polyphenols to protect and increase the bioavailability of polyphenols.

Combining polyphenols with bioavailability-boosting compounds can also ensure consumers reap product health benefits. For instance, a study recently published in Molecular Nutrition & Food Research demonstrated Sabinsas BioPerine® piperine significantly improved the in vivo bioavailability of resveratrol (as Resvenox®, from Sabinsa).⁴ According to Sabinsa, resveratrols poor in vivo bioavailability is due to its rapid metabolism, a process known as glucuronidation. In C57BL mice, the degree of exposure (i.e., the area under the curve [AUC]) to resveratrol was enhanced by 229 percent, and the maximum serum concentration (Cmax) was increased by 1,544 percent with the addition of piperine.

The issue is not what one might think, that piperine helped resveratrols absorption, but what was happening is that resveratrol alone is very rapidly metabolized, said Steven Dentali, Ph.D., chief science officer, American Herbal Products Association (AHPA). Its probably true for perhaps the whole class of polyphenols; its not that they arent getting in the body to have activity, its that they are getting in, and they are metabolized so quickly that they dont have enough time to exert health benefits. With resveratrol, what is happening is that piperine is slowing down the metabolism here, inhibiting the enzymes that metabolize resveratrol.

Still, many manufacturers want to get more of the good compounds into their consumers blood, even if scientists arent quite sure what those compounds are. The polyphenol antioxidant activity cannot be ignored, but it has been questioned as of late.

As Kara Lambert, product manager, BI Nutraceuticals, explained the theory, Polyphenols are an antioxidant, so they protect the body against oxidative stress caused by free radicals. It is thought that free radicals are unstable molecules and need to gain an additional electron to remain stable, thus they attach themselves to molecules in the body and can cause oxidative damage. Polyphenols may attach to the free radical to give them the added electron needed to be stable, thereby reducing the damage they may cause to the body.

This antioxidant action supports cardiovascular health, cognitive health, skin health, immune health and a healthy inflammatory response, Wuagneux said. Individuals with certain conditions, such as obesity and diabetes, produce more free radicals and, therefore, need more antioxidant support. Also, exercise induces high free radical products, and polyphenols should be used in any exercise performance product.

Oxygen radical absorbance capacity (ORAC) is the most recognizable test for antioxidant activity. For instance, Bernd Bonnländer, Ph.D., head of product development at Plantextrakt, a business unit of the Martin Bauer Group, noted its polyphenols in final beverages have ORAC values of up to 9,000 points per liter.

However, Lifton said ORAC only shows antioxidant potential in vitro. The problem is that just because youre able to show potency in a test tube doesnt mean it translates into potency in the body, he said.

Dentali agreed, adding, Its not that ORAC isnt a way to measure antioxidant activity; it is in that assay. But it doesnt appear that theres direct antioxidant activity in the body. It very well may be that eating compounds with high ORAC values do confer health benefits, but it may not be the same mechanism that gives it a high ORAC number.

And a high ORAC may even be harmful. In 2011, a USDA study reported accumulating evidence suggests that reactive oxygen species exert essential metabolic functions, and that removal of too many of them can upset cell signaling pathways and actually increase the risk of chronic disease.⁵ It is imperative that the food industry be aware of progress in this field to present the science relative to foods in a forthright and clear manner, the authors wrote.

Some research suggests polyphenols health promoting effects go beyond their antioxidant actions. According to a review published in the American Journal of Clinical Nutrition, the antioxidant properties of polyphenols have been widely studied, but it has become clear that the mechanisms of action of polyphenols go beyond the modulation of oxidative stress.⁶ And Helmut Sies, long-time polyphenol researcher at Heinrich-Hein University, Dusseldorf, Germany, said the role of polyphenol metabolites as bioactives target specific enzymes, such as NADPH oxidases or lipoxygenases, which provides a basis for the molecular action of polyphenols, rather than unspecific direct antioxidant effects.⁷ He cautioned against using assays of total antioxidant capacity (TAC) in blood plasma as a way to demonstrate functionality.

If it isnt antioxidants behind polyphenols benefits, perhaps its how they affect the bodys molecules. A 2010 study from London reported procyanidins, flavonoids found in apples, cranberries and grapes, inhibited endothelin-1 synthesis.⁸ Endothelin-1 is a human gene best known for its role in constricting blood vessels. Procyanidins also decreased expression of Kruppel-like factor 2 (KLF2), a key endothelial transcription factor with a broad range of anti-atherosclerotic actions including suppression of endothelin-1 synthesis. A study on grape seed extract (GSE), which is full of proanthocyanidins, also affected gene expression in the brain.⁹ In this 2004 study from University of Alabama, Birmingham, analysis of brain homogenates from adult female rats that were fed diets supplemented with 5-percent GSE for six weeks identified 13 proteins that were altered. These proteins are inversely associated with Alzheimers disease. And, a 2007 review by New Zealand researchers said recent evidence shows polyphenols induce endogenous-protective enzymes and mediate regulation of cellular processes such as inflammation.¹0 These effects may occur at concentrations much lower than required for effective radical scavenging, they said.

Anil J. Shrikhande, Ph.D., president, Polyphenolics, noted its GSE MegaNatural-BP was shown to affect the endothelium layer of major arteries and provide increased activity of NOS (nitric oxide synthase) in the generation of NO, which provides further evidence of polyphenols molecular actions.¹¹

Regardless of the reason behind the benefit of polyphenols, Shrikhande said ingredient suppliers should be able to provide research to back up their products. The nutraceutical industry is interested in ingredients that provide help in reducing specific health conditions, and their effects can be monitored by the subjects or their physicians. Companies interested in marketing such products require good science and actual human clinicals to show the effect as antioxidant or blood pressure management.

Stability

As interesting as it is to explore polyphenols mechanism of action, manufacturers cannot stop there when it comes to creating products. No matter what causes the health benefits, keeping plant compounds fresh and stable will always be an issue.

Wuagneux said polyphenol ingredients dont pose too many challenges for dietary supplement manufacturing. They have a fairly good shelf life (requiring some overage, but not too much) in dry form, and dry blending them with other ingredients will not cause any degradation. They do need to stay away from high heat or intense light, but that is not a big obstacle in capsule or tablet form. However, challenges can arise when formulating them into functional foods, especially beverages, he said. In an aqueous environment, the polyphenol stability is decreased. Plus, light and heat can degrade them further when they are in this environment. Therefore, a bigger overage is required if the product is making any kind of quantitative claim (e.g., X mg of polyphenols).

Artaria said stability is one of the top issues that comes with processing polyphenol ingredients. Polyphenols are relatively unstable; this is true in general, but in particular when glycosides are attached to polyphenols, he said Polyphenols can be easily oxidized. Polyphenols are quite termolable, and at high temperatures, they can easily be degraded.

As generally aqueous extracts, Bond said the main manufacturing purpose is to avoid oxidization. They are sensitive to oxygen and temperature variation during the process, and they can react easily with other compounds according to the formulation in which they are used, she said, adding the best formulation method for polyphenolic compounds is the powder form. Under the dried form, you limit presence of water, and you decrease the exchange with oxygen. So you can extend the shelf life more than three years, but of course, the family of polyphenolic compounds is so hugemeaning that according to the nature of your polyphenolic compounds, you need to adjust the formulation.

Oxygen, high temperatures and intense processing can degenerate nutritional compounds in food, making nutrient loss another issue for manufacturers, according to Christina Khoo, senior manager, research sciences, Ocean Spray Ingredient Technology Group (ITG). To create added-value, healthful and delicious foods, manufacturers are well-advised to consult with their ingredient supplier for their ingredient knowledge and new product development expertise, she said.

Taste

While polyphenols found in nature often come from tasty berries and other fruit, using them isolated in products can create a taste some call astringent; others call it bitter. Foods that are high in polyphenols often possess a naturally astringent taste, Khoo said. When developed carefully, this can form the base of a pleasant, tart taste profile. With inadequate product development skills and sensory testing methods, however, polyphenol-rich foods can taste bitter and deter consumers.

Lifton added, Polyphenols tend to have a very bitter taste profile. in particular applications, such as functional beverages, where polyphenols have a lot of promise, the taste needs to be masked, and thats not always easy. Lifton said Maypro ran into this issue when it developed functional beverage prototypes for customers. Maypro worked with a flavor company and ultimately decided to use a combination of stevia and sugar to mask the taste. He said stevia alone had its own aftertaste issue, and he noted some outlets such as Whole Foods Market dont accept certain sweeteners such as sucralose.

Artaria weighed in, using both terms: Polyphenolics generally taste bitter or astringent, and this should be in some cases masked, he said. Masking this bitterness is especially needed when high dosages are to be incorporated in food matrices.

Wuagneux noted manufacturers can avoid taste issues by using capsules or tablets to deliver polyphenol ingredients.

Color

Again, whats loved in naturethe rich colors of the plants that carry polyphenolsmay not be wanted in finished goods. Polyphenols are usually colorful, which may be problematic for some food matrices and, in some extreme cases, also for the cleaning of the manufacturing tools, Artaria said.

Just one example is the popular ingredient curcumin, extracted from turmeric, a spice traditionally used in Indian cooking that tints food bright gold. That golden powder can coat a manufacturing facility and make quality control (QC) efforts challenging. However, there are solutions; Sabinsa, a supplier of curcumin, has a dedicated area of its Provo, UT, facility to handle milling, blending, dispensing and encapsulation of products containing curcumin.

Sourcing

Consumers love that polyphenols come from nature, but this means manufacturers must contend with Mother Nature. Environmental factors have a major effect on polyphenol content, Bond said. These factors may be pedoclimatic (soil type, sun exposure or rainfall) or agronomic (culture in greenhouses or fields, biological culture, hydroponic culture, fruit yield per tree, etc). Exposure to light has a considerable effect on most flavonoids. The degree of ripeness considerably affects the concentrations and proportions of the various polyphenols. She added the polyphenol content of vegetables produced by organic or sustainable agriculture is certainly higher than that of vegetables grown without stress, such as those grown in conventional or hydroponic conditions. However, she noted few studies directly addressed this issue.

Lambert said BI can also be challenged by the environment. There are some years where the harvest may not be good due to inclement weather and cause low assay results for polyphenols, which may cause higher market prices, she said. It is important to source your ingredients from quality manufacturers that show full visibility and traceability to their products. She noted BI has a close relationship with its suppliers, which allows it to monitor the quality of ingredients it supplies customers.

Frank Schönlau, scientific director, Horphag Research, said polyphenols are not all created equal; There are huge varieties in nature. He added this is why Pycnogenol®, a French maritime pine bark extract, is being standardized to the compositional aspects described in the United States Pharmacopoeia (USP). The laboratory procedures detailed in the USP ensure the consumer can always obtain the same product, which is covered by research on safety and efficacy, he said.

Safety

Schönlau brings up the issue of safety and, as its been told a hundred times, just because its natural, doesnt mean its safe. A 2005 article published in the American Journal of Clinical Nutrition, for example, reported certain polyphenols may have carcinogenic/genotoxic effects or may interfere with thyroid hormone biosynthesis.¹² The authors, who reported on information presented at the first International Conference on Polyphenols and Health, Vichy, France, in November 2003, said isoflavones are of particular interest because of their estrogenic activity, for which beneficial as well as detrimental effects have been observed. Furthermore, they wrote consumption of polyphenols inhibits nonheme iron absorption and may lead to iron depletion in populations with marginal iron stores. And, polyphenols may interact with certain pharmaceutical agents and enhance their biologic effects. It is important to consider the doses at which these effects occur, in relation to the concentrations that naturally occur in the human body.

Referencing this study, Bond said, In evaluations of experimental studies, it's important to look carefully at the doses used. She added, Furthermore, some of these polyphenolic supplements may appear safe when isolated from food plants, but the method of extraction used to produce the supplements may influence the nature of the compounds ingested, and thus the safety of the product. This occurred with a hydroalcoholic extract of tea buds, sold as a slimming supplement, which was withdrawn from the market because of severe cases of liver toxicity.

Artaria said manufacturers can face problems at any stage of the production process from the growing of the botanical species to the final analytical analysis. That is the reason Indena created its Indena 30 Quality Control System, a process that maintains more than 30 quality controls from start to finish. Indenas first step involves good agricultural and collection practices (GACP), and then it conducts a complete chemical analysis, which includes microbiological and contaminant testing, Artaria said. Indena continues this process through adhering to GMPs (good manufacturing practices). The finished product also undergoes final analysis and documentation review, which includes HPLC and NMR tests.

Bonnländer said Plantextrakt ensures safe products by having all raw materials and final extracts analyzed by PhytoLab, an accredited laboratory specializing in analyses and regulatory services for herbal products. With their support, we are able to select raw material batches with high-polyphenol content for our standardized extracts, he said. Besides polyphenol contentwhich should be very highPhytoLab analyzes unwanted substances like impurities, aflatoxins and pesticides to guarantee a safe product that lives up to its promise.

Manufacturers may be able to rely on FDAs non objections to new dietary ingredient (NDI) notifications and self-affirmed GRAS (generally recognized as safe) statuses, which are processes to show safety of ingredient use in dietary supplements and functional foods, respectively.

In terms of toxicity, we have extensive safety data that was presented to FDA for the NDI notification and the GRAS board, Lifton said regarding Oligonol. He noted the lychee ingredient contains a small amount of green tea, which has been known to cause safety issues in large doses. But its not purified, and its only 15 percent by weight. We use the green tea to cap the long-chain molecules to make the product stable. We dont use it for the bioactive properties of green tea. We just use it to stabilize the compound.

Delivery

FDA has not objected to numerous polyphenols being used in both foods and supplements, and manufacturers have responded by including them in products ranging from beverages, capsules, breads, cookies, personal care products, cheeses and cosmetics.

Our main customers are from the beverage industry, including vending, but there is also a need for plant extracts in infant nutrition, and in the confectionery and functional food industries, Bonnländer said.

Artaria said the most common delivery forms are dietary supplements in the form of soft gels, tablets, sachets and hard gels. However, I believe gums and strips will become more common.

Lifton said Maypro has seen an interested interest in the sports nutrition market. We have a number of human clinical studies on the benefits of Oligonol for the reduction for post-exercise fatigue and increasing endurance as well as increasing NO, which increases blood flow. More blood flow to the heart means more oxygen to the heart and muscles, which has the benefits of reducing fatigue and increasing energy.

Khoo noted Ocean Spray customizes its cranberry forms depending on what type of finished good the manufacturer offers. Cranberry is available in powder form for nutritional supplements and in puree and concentrate forms for sauces and beverages, she said, adding cranberry ingredients are used across the globe in a wide range of applications. Some of the more unusual combinations include Italian-inspired cranberry paninis and panna cotta, and Asian-styled cranberry wontons with cranberry jalapeno dipping sauce.

Future

Were sure to see more interesting polyphenol products in the future, and those products will be supported by even more research than is currently available. Growth in this area will be from a combination of science and growing consumer awareness. Its still in its nascent stages; its where antioxidants were 20 years ago, Lifton said. We talk about antioxidants 2.0, and this would be the case with polyphenols. Polyphenols are one of the most exciting areas of innovation in the industry. I think its going to be one of the next big areas to explode.

Check for that explosion to come in the form of more consumer media headlines. What may never be in consumer news articles are the careful steps manufacturers take to ensure their products are bioavailable, stable, safe and the correct color. But without these meticulous methods, consumers would forgo polyphenol supplements let alone Asian-styled wontons.

References for Polyphenol Processing

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3.       Morazzoni Pet al. Comparative pharmacokinetics of silipide and silymarin in rats. Eur J Drug Metab Pharmacokinet. 1993 Jul-Sep;18(3):289-97.

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5.       Finley JW et al. Antioxidants in foods: state of the science important to the food industry. J Agric Food Chem. 2011 Jul 13;59(13):6837-46.

6.       Scalbert, A; Johnson, I; and Saltmarsh, M.  Polyphenols: antioxidants and beyond. Am J Clin Nutr. 2005;81(1)215S-217S.

7.       Sies H. Polyphenols and health: update and perspectives. Arch Biochem Biophys. 2010 Sep 1;501(1):2-5. Epub 2010 Apr 14.

8.       Caton PW et al. Regulation of vascular endothelial function by procyanidin-rich foods and beverages. J Agric Food Chem. 2010 Apr 14;58(7):4008-13.

9.       Deshane J et al. Proteomics analysis of rat brain protein modulations by grape seed extract.  J Agric Food Chem. 2004 Dec 29;52(26):7872-83.

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