The study looked at chocolate's (Total Antioxidant Capacity) TAC and the amount of procyanidins it contained. Milk chocolates have the lowest TAC and procyanidin levels, and baking chocolates contain low levels of procyanidins. The alkalinizing process used to reduce the acidity of chocolates substantially lowers the quantity of procyanidins. Cocoa powder, being the least processed chocolate, contains the highest levels of TAC and procyanidins.
Those are the results of a study by Agricultural Research Service (ARS) scientists and their cooperators interested in the total antioxidant capacity (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.
The researchers found natural cocoa contains the highest capacity of the antioxidant procyanidin.
Ronald L. Prior, an ARS nutritionist at the Arkansas Children's Nutrition Center (ACNC) in Little Rock, Ark., presented the study's results in San Diego, Calif., today with Liwei Gu and Xianli Wu of ACNC and Jim Harnly, a chemist at the ARS Beltsville (Md.) Human Nutrition Research Center.
They presented the findings at Experimental Biology 2005, an annual meeting that brings together 16,000 biological and biomedical scientists from dozens of different disciplines.
The researchers found natural cocoa powders contained the highest levels of TAC and procyanidins, which were found to be the dominant antioxidant in chocolates.
Milk chocolates, which contain the least amount of cocoa solids, had the lowest TAC and procyanidin levels.
Baking chocolates contained fewer procyanidins, because they contained more fat (50-60 percent) than natural cocoa.
Alkalinization, used to reduce the acidity and raise the pH of cocoa, such as Dutch chocolates, was found to markedly reduce procyanidin content.
Researchers concluded that chocolates containing higher amounts of cocoa ingredients have higher procyanidin contents, therefore, higher antioxidant capacities.
Nine major manufacturers provided commercially available chocolate and cocoa samples and the National Institute of Standards and Technology provided its Standard Reference chocolate for analysis.