Study Demonstrates Effective Bioavailability of Polyphenols in a Convenient Juice Drink

BRUSSELS, June 23, 2010 – New research published in a special online issue of Molecular Nutrition and Food Research 1, building on an earlier report in the Journal of Agricultural and Food Chemistry, highlights that a polyphenol rich (P-R) juice can effectively deliver the intended blend of bioavailable polyphenols which would normally require consumption of several different plant-derived foods and drinks. It was found that the polyphenols in the P-R juice were effectively absorbed into the blood stream, showing the potential to deliver these compounds via a convenient juice drink.

The health benefits associated with eating fruit and vegetables on a daily basis are in part linked to the ingestion of bioactive components that include essential vitamins, minerals, fibre and polyphenolic compounds. This study, one of a number of recently completed research projects supported by The Coca-Cola Company, was carried out by the University of Glasgow in Scotland and investigated the bioavailability, absorption and metabolism of a diverse spectrum of phenolic and polyphenolic compounds in a prototype polyphenolic-rich (P-R) juice drink. The aim of the project was to determine if a beverage with a blend of extracts from a variety of sources can deliver the intended phenolics to the body. This research was designed to provide information on whether blends of fruit and tea extracts could serve as a convenient means of delivering additional polyphenols to the diet.

The prototype drink was produced after screening a range of potential constituents found in natural polyphenol sources such as grape, apple, citrus fruit and green tea. The absorption and metabolism of polyphenol parent compounds and/or their metabolites were analysed from plasma and urine samples collected over a 24-hour period after ingestion of the P-R beverage by ten healthy human volunteers. Results from the plasma pharmacokinetics and recovery of urinary metabolites demonstrated that the availability of flavan-3-ols from tea, flavanones from citrus, dihydrochalcones and 5-O-caffeoylquinic acid from apple, both in terms of their identity and quantity, were, in most instances, not markedly different to those reported in other feeding studies with green tea, orange juice, apple cider and coffee. This indicates that the combination of polyphenolic compounds in the P-R juice drink are absorbed and excreted to a similar extent as they would be when consumed from individual natural sources. Furthermore the different types of polyphenols were shown to be absorbed into the body at different rates and in different locations along the intestinal tract suggesting that potential protective polyphenol metabolites will be in the blood stream for a longer period of time when given together than if a single source of these extracts were provided on its own.

Commenting on the study Professor Alan Crozier, research lead, said "We are very encouraged by this research, it's a great indicator that a diversity of polyphenols can be delivered to the body by consumption of a glass of a fruit juice and juice drink, which is especially convenient to consumers with a busy life-style."

Additional research

A further study, published in the May issue of the Journal of Agriculture and Food Chemistry researched the biovailability and metabolism of flavanones, the main category of polyphenols present in orange, in a flavanone enriched Minute Maid/Cappy orange juice beverage. Orange juice is a rich source of flavanones which present in both soluble and precipitated forms. The study showed that the solubility of the flavanones, and particularly that of hesperidin, in the juice is a key factor for the absorption of orange flavanones. In addition, drink processing can also affect the flavanoid composition and therefore the bioavailability of flavanones.

The study, undertaken by Professor Tomas-Barberan and his team at the CEBAS Institute (CSIC, Murcia, Spain) 4 has shown that increasing concentrations of the flavanones in the juice by adding an orange flavanone extract affected the proportion of soluble/insoluble compounds in the haze and increased the absorption in the gut and the bioavailability of these compounds.

Professor Tomas-Barberan commented "Both of these studies help to define more clearly the parameters under which polyphenols can be made available to the body. This research also forms an important starting point on which to base further investigations into the benefits of polyphenols, in particular, flavanones from citrus fruits."

The study was funded by The Coca-Cola Company. The Coca-Cola Company, in collaboration with leading international scientists, is continuing to invest in research to explore the benefits of polyphenols and ways in which to make them conveniently available to consumers.

References

1. Borges, G. et al. Bioavailability of multiple components following acute ingestion of a polyphenol-rich juice drink. Mol. Nutr. Food. Res. 2010, DOI:10.1002/mnfr.200900611.
2. Mullen, W. et al. Identification of metabolites in human plasma and urine after consumption of a polyphenol-rich juice drink. J. Agric. Food Chem. 2010, 58, 2586-2595
3. Crozier, A., Jaganath, I. B., Clifford, M. N., Dietary phenolics: chemistry, bioavailability and effects on health. Nat. Prod. Rep. 2009, 26, 1001–1043.
4. Vallejo , F. et al. Concentration and solubility of flavanones in orange beverages affect their bioavailability in humans. J. Agric. Food Chem. 2010, 58, 6516–6524