AbstractBACKGROUNDCocoa bean husk (CBH) is the principal by‐product of the cocoa industry and a significant agro‐industrial residue. In this study, using different hydrothermal treatments of CBH, it is shown that CBH is an important source of bioactive compounds, including theobromine, epicatechin and catechin.RESULTSTreatment over 150 °C significantly increased the yield of total and individual phenols and theobromine as well as the antioxidant capacity of the liquid fraction. A total of 52 different genotypes of CBH harvested in two seasons of production were analyzed. Overall, higher amounts of total phenols, theobromine and epigallocatechin were detected in samples from the 2015 season, while samples from 2014 had higher quantities of catechin and similar quantities of epicatechin.CONCLUSIONCBH treatment at 170 °C for 30 min produces an antioxidant‐rich extract high in phenols (55 mg g−1), sugars (220 mg g−1) and theobromine (56 mg g−1) that is suitable for applications in the food, cosmetic and nutraceutical industries. © 2018 Society of Chemical Industry