Response Surface Methodology for Efficient Maceration of Cinnamon (Cinnamomum burmanni) Bark

Cinnamon (Cinnamomum burmanni (Nees & T. Nees) Blume) is a herbal plant rich in polyphenols and flavonoids, which act as antioxidants, although the effectiveness is greatly influenced by the extraction conditions. This study aims to optimize the cinnamon extraction process for cinnamon bark using maceration combined with pressing, correlation of TFC and TPC to antioxidant activity, also quantify the flavonoid compound in the optimized extract. The evaluation focused on maximizing the outcomes of 2,2-diphenyl-1-picrylhydrazyl (DPPH), cupric ion reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP), total flavonoid content (TFC), and total phenolic content (TPC). Response Surface Methodology employing a Box–Behnken design was utilized, incorporating three extraction factors: extraction duration (10–40 minutes), crude drug - solvent ratio (1:3–1:10), and ethanol concentration (70–96%). The optimal extraction condition was determined to be 40 minutes of extraction duration, a crude drug - solvent ratio of 1:6.5, and 96% ethanol. Under the optimal extraction condition, the extract yielded TPC and TFC values of 351.941 ± 0.045 mg GAE/g and 0.169 ± 0.013 mg QE/g, respectively, along with DPPH, CUPRAC, and FRAP antioxidant capacities of 1.376 ± 0.039, 796.646 ± 0.243, and 540.866 ± 0.013 mg AEAC/g. Overall, the phenolic and flavonoid constituents in the ethanol extract of cinnamon bark showed a clear relationship with the antioxidant responses measured by DPPH, CUPRAC, and FRAP. The optimized extract also contained rutin (3.15 ± 0.08 mg/g) and apigenin 7-O-glucoside (20.79 ± 0.39 mg/g).