Investigating the total antioxidant capacity (TAC) of a range of cocoa powders, from processed to semi-sweet chocolate, US researchers found that natural cocoa contains the highest capacity of the antioxidant procyanidin.
Procyanidins, mixtures of oligomers and polymers composed of the flavonoids catechin or epicatechin, are found in a range of foods, including nuts, fruits, spices and some vegetables.
Flavonoids found in chocolate include the main flavonoid epicatechin, and catechin, and polymers of these, the proanthocyanidins.
Some epidemiological studies suggest that high intakes of flavonoids are associated with the maintenance of cardiovascular health, although other factors may also account for the results.
In vitro (test tube) and in vivo (in humans) studies have shown that cocoa flavonoids and certain chocolates may decrease low-density-lipoprotein (LDL) oxidation, may modulate platelet activation and could positively affect the balance between certain hormones, or eicosanoids. These actions can play a role in maintaining heart health.
But scientists are only starting to understand the significance, and health benefits, of procyanidins' components.
Researchers at the US government-backed Agricultural Research Service (ARS) investigated the TAC and procyanidin levels of six chocolate and cocoa products: natural (unsweetened) cocoa powders, Dutch processed (alkalinized) cocoa powders, unsweetened baking chocolates, semi-sweet chocolate baking chips, dark chocolates, and milk chocolates.
Their findings suggest that natural cocoa contains the highest capacity of procyanidin.
Presenting their conclusions this week in the US at the Experimental Biology 2005 conference, the ARS scientists said milk chocolate reported showed the least amount of cocoa solids, with the lowest TAC and procyanidin levels.
Baking chocolates contained fewer procyanidins, because they contained more fat (50-60 per cent) than natural cocoa.
Processing conditions like alkalinisation, used to reduce the acidity and raise the pH of cocoa, such as Dutch chocolates, markedly reduced procyanidin content, the researchers report.
Pushing the potential antioxidant activity of chocolate in a range of new formulations may help confectionery makers scoop up additional sales in an stagnant market marked by eroding sales as the increasingly health conscious consumer turns away from chocolate products.
"Western European sales have also been affected by a rising sense of health consciousness, having a particular impact on the chocolate segment," John Band, consumer markets analyst at Datamonitor said recently.
Sales growth for chocolate across Europe is slated to slow down in future years, with value sales likely to reach €5.6 billion by 2007, an increase of just 4 per cent.
Britain is far ahead of its continental rivals when it comes to chocolate consumption, accounting for 32 per cent of the total market by value in 2003 - estimated at €5.3 billion.
But a recent report from Datamonitor shows chocolate consumption is slowing down as health and diet concerns impact sales.
According to Datamonitor, the pace of growth in the market is slated to slow down, kicked off in 2004 when overall chocolate volume sales rose by less than 1 per cent to 605m kg.