Writing in the Journal of Agricultural and Food Chemistry Juan Carlos Espin de Gea and colleagues report that omitting the traditional fermentation and roasting steps used in the processing of cocoa beans can achieve higher levels of flavonoids.
The researchers, including scientists from cocoa-ingredient manufacturer Natraceutical Group, also tested the bioavailability of these flavonoids in humans and found to be five-fold higher than from a conventional cocoa powder.
"All of these studies confirm that through improved processing, the flavonoid composition of cocoa powder can be enhanced (mainly flavanol monomers and dimers) and that this enhancement leads to an increase in the cocoa flavonoid metabolites present in plasma and in urine showing a higher bioavailability," wrote the authors.
The health benefits of antioxidant-rich chocolate have received much recognition in recent years, with positive findings from a number of studies impacting on consumer awareness.
Chocolate manufacturers are using high cocoa content (over 70 per cent) as a means of differentiation, and cocoa has also received attention for its potential in functional food applications.
The flavonoid-enriched cocoa powder was prepared by blanching the fresh cocoa beans in hot water in order to inactivate the polyphenol oxidase enzyme that is responsible for the oxidation of polyphenols in the bean.
The beans were then dried, deshelled, milled, partially defatted, and vacuum-dried.
Comparison with conventional cocoa powder showed that the flavonoid-rich powder contained four times more procyanidins, and eight times more epicatechin and procyanidin B2, than the conventional powder.
To test the bioavailability of these flavonoid six healthy volunteers consumed a milk drink made with flavonoid-enriched cocoa.
The same volunteers later drank chocolate milk made from traditional cocoa.
Blood and urine tests established the bioavailability of flavonoids in the enriched-milk drink, and showed that epicatechin glucuronide (the main metabolite detected in the blood) was five-fold higher following consumption of the flavonoid-rich powder than the conventional powder.
"Previous reports have linked the cardiovascular beneficial effects of cocoa consumption with the accumulation of procyanidin metabolites in plasma," said the researchers.
"In this context, a higher health beneficial effect upon the intake of a cocoa-derived product based on a process that preserves flavonoid content cannot be ruled out," they concluded.
Natraceutical shifted its attention to cocoa from caffeine in 2003, and has developed a range of ingredients with different concentrations of the natural antioxidants found in cocoa for food makers looking to enhance the health properties of their products.
These are available to the market under the CocoanOX brand.
Chocolate giant Mars recently filed a lawsuit against Natraceutical, alleging that the Spanish company is infringing its patents on polyphenol-rich cocoa extracts by selling CocoanOX extracts in the United States.
A spokesperson for Natraceutical told NutraIngredients.com that the process has been patented by the company and that the new process published in the Journal of Agricultural and Food Chemistry was different to the disputed patents.
Source: Journal of Agricultural and Food Chemistry Published on-line ahead of print, doi: 10.1021/jf070121j
"A New Process to develop a Cocoa Powder with Higher Flavonoid Monomer Content and Enhanced Bioavailability in Healthy Humans" Authors: F.A. Tomas-Barberan, E. Cienfuegos-Jovellanos, A. Marin, B. Muguerza, A. Gil-Izquierdo, B. Cerda, P. Zafrilla, J. Morillas, J. Mulero, A. Ibarra, M.A. Pasamar, D. Ramon, J.C. Espin