Characteristics of anthocyanins in fortified cakes: a promising potent inhibitor of sucrase, α‐glucosidase and lipase

Summary Anthocyanins are well‐known compounds that can improve gastrointestinal effects and have the potential to be utilised as an ingredient in functional foods. However, the true pharmacological role that they carry out in human body has been largely elusive. Thus, this study was aimed to investigate the inhibitory action of anthocyanins in a cake matrix on intestinal enzymes – α‐glucosidase, sucrase and lipase. Anthocyanin‐rich black rice extract powder (ABREP) was incorporated into cake at the levels of 0, 0.25, 0.5, 1 and 2% of flour weight. The physicochemical properties and in vitro digestibility of the cake, as well as enzyme inhibitory effects of anthocyanins were investigated. Degradation of anthocyanins in the batter occurred up to 68% at the 2% fortification level while the cake matrix asserted a protective effect on the remaining anthocyanins, keeping them by up to 84% after baking. The antioxidant capacity of cakes was increased by nine times when cake was fortified with 2% ABREP. The digestion rate of sucrose was reduced by 4.6 times at a 2% fortification level as compared to the control. Furthermore, cake with 2% ABREP addition showed 150%, 41% and 278% higher inhibitory effects against sucrase, α‐glucosidase and lipase as compared to the one with 0.5% addition, respectively. This study provides an in‐depth understanding of the potential of anthocyanin‐fortified foods for helping people with elevated blood glucose and triglyceride levels.