Can we conserve trans-resveratrol content and antioxidant activity during industrial production of chocolate?

Background: Cocoa exhibits high content of phenolic compounds, among which trans-resveratrol stands out, associated with several bioactive activities such as antioxidant properties. Chocolate contains reduced amounts of these bioactive compounds due to losses during the production process. Therefore, this study aimed to assess changes in total phenolic content, and specifically trans-resveratrol, as well as changes in the antioxidant activity of cocoa and its products during industrial production of chocolate.

Results: A total of ten different cocoa products were analyzed. The processes of fermentation and roasting caused significant loss of total phenolic compounds and antioxidant activity. The high temperature of roasting had a major influence on this loss (71% for total phenolic compounds and 53-77% for antioxidant activity), except for trans-resveratrol. The trans-resveratrol content formed after fermentation (9.8 μg kg ) showed little variation during the processes, and it was detected in higher concentrations both in natural (11.4 μg kg ) and in alkalized cocoa powder (13.5 μg kg ). Alkalization of cocoa products led to loss of capacity of deactivating superoxide radical.

Conclusion: These findings contribute to the optimization of the production process of chocolate and other food products containing cocoa and its derivatives, aiming to better preserve their bioactive compounds. © 2018 Society of Chemical Industry.