Optimization of the acid hydrolysis process for the extraction of Rosa roxburghii Tratt-bound phenols and antioxidant, α-glucosidase and lipase inhibitory activities in vitro

The aim of this study was to investigate acid hydrolysis-bound phenols from Rosa roxburghii Tratt and their biological activities in vitro. The optimal extraction parameters were as follows: HCl concentration of 7 mol/L, extraction time of 10 h and material-liquid ratio of 1:40 g/mL. The highest yield of bound polyphenols was 495.64 ± 11.66 mg GAE/100 g DW. There were 24 phenolic compounds and 14 flavonoids released by acid hydrolysis. The antioxidant study showed that the RRT-BPs had a certain scavenging ability of free radicals in a dose-dependent manner. RRT-BPs showed good inhibitory activity against α-glucosidase and pancreatic lipase, respectively, and RRT-PBs acted as anticompetitive and mixed inhibitors against α-glucosidase and pancreatic lipase, respectively. Our study suggests that acid-hydrolysed bound phenols have good prebiotic properties and can be used as a supplement to existing alkaline-hydrolysed bound phenols to prevent chronic diseases such as diabetes and obesity.