Good news, chocoholics: Scientists have found a way to not only make chocolate more nutritious, but also to enhance its taste. Praise science!
By making a couple of simple adjustments to the earliest processing steps, researchers found that they could boost the content of health-promoting compounds in cocoa beans and also improve the resulting chocolate's flavor, making it sweeter. The work waspresented at the 249th National Meeting & Exposition of the American Chemical Society and published in African Journals Online.
Humans have been gobbling cocoa for thousands of years, but it is only relatively recently that scientists have demonstrated that dark chocolate and cocoa could actually be beneficial to our health due to the fact that they are rich in biologically active compounds known as polyphenols. These chemicals are known to have a variety of desirable properties, such as antioxidant and anti-inflammatory properties, and their consumption has been linked to various positive health effects, such as a reduction in blood pressure and reduced incidence of stroke and cardiovascular diseases.
Unfortunately, some of the steps required to transform raw cocoa beans into a form that can be used in the production of delicious candy bars are known to alter the content of these compounds. After the pods are cut down from cocoa trees, they are split open and the beans are removed. These are then fermented for several days in banana-lined baskets before being dried in the sun and finally roasted. This roasting stage is critical to the flavor outcome of chocolate, but it also causes the beans to lose some of their polyphenols.
Armed with this knowledge, scientists from the University of Ghana set out to find a way of retaining these important compounds without negatively affecting its taste. They decided to start off by adding in another stage to the process, which involved storing the pods prior to fermentation. After testing out a range of conditions, the researchers found that storing them for 7 days prior to processing as normal resulted in the highest antioxidant content.
Next, the team decided to examine whether they could optimize the roasting process so that more polyphenols could be retained without sacrificing flavor. Traditionally, beans are roasted for between 10-20 minutes at 120-130oC, but they found that roasting at a lower temperature for 45 minutes improved the antioxidant activity of the beans. Furthermore, when this roasting technique was combined with the storage step, the beans had both increased antioxidant activity and a higher polyphenol content. Not only that, but the chocolate produced using this method was also sweeter.
The researchers believe that these positive effects are due to the fact that the storage stage allowed the beans to have more contact with the sweet surrounding pulp, which can alter the biochemical and physical properties of the beans. “This aided the fermentation process and enhanced antioxidant capacity of the beans, as well as the flavor,” notes lead researcher Emmanuel Afoakwa, adding that this technique could be particularly useful in countries where cocoa beans have a less intense flavor and lower antioxidant activity, such as in Latin America. Afoawka now plans to continue this work by further scrutinizing different storage and roasting techniques in order to optimize the process.