The quest for healthier chocolate

Chocolate lovers rejoice - healthier, tastier chocolate could be on its way.

Cocoa undergoes several steps before it takes shape as a chocolate bar. Pods are cut down from cocoa trees, then split open to remove the white or purple cocoa beans. They are fermented in banana-lined baskets for a few days and then set out to dry in the sun. The next step is roasting, which brings out the flavour but also destroys some of the healthful polyphenols (antioxidants).

Researchers from the University of Ghana set out to find a way to retain more of the polyphenols, without sacrificing the flavour. “We decided to add a pod-storage step before the beans were even fermented to see whether that would have an effect on the polyphenol content,” said Emmanuel Ohene Afoakwa, PhD.

Afoakwa’s team divided 300 pods into four groups that were either not stored at all or stored for three, seven or 10 days before processing. He reports that the seven-day storage resulted in the highest antioxidant activity after roasting.

The researchers also studied the effects of roasting the beans at a lower temperature for a longer time and discovered that this slower roasting increased the antioxidant activity compared to beans roasted with the conventional method.

In addition, the beans that were stored and then slow roasted had more polyphenols and higher antioxidant activity than beans whose pods were not stored prior to fermentation, said Afoakwa. He explained that this process likely allowed the sweet pulp surrounding the beans inside the pod to alter the biochemical and physical constituents of the beans before the fermentation. “This aided the fermentation processes and enhanced antioxidant capacity of the beans, as well as the flavour,” he said.

The research was presented at the 249th National Meeting & Exposition of the American Chemical Society (ACS) in Denver, Colorado.