Optimization of Extraction of Phenolic and Antioxidant Activities from Celosia cristata Seeds Using Response Surface Methodology

This study aims to determine the optimal sonication extraction conditions to obtain the highest phenolic and antioxidant compounds from Celosia cristata L. (CCL) seeds. Effects of extraction variables including extraction time (15-60 min), particle size (60-100 mesh), solid-solvent ratio (1:5–1:20 g/mL), and ethanol concentration (50-96%) on the total content Phenolic (TPC) and total antioxidant activity (TAC) by DPPH, FRAP, and CUPRAC methods were determined and optimized using the response surface methodology (RSM). Particle size, solid-solvent ratio, and ethanol concentration significantly affected the yield of TPC and TAC, while extraction time had no significant effect on TPC and TAC in the tested ranges. Optimum CCL seed extraction conditions to achieve maximum TPC (1,687mg GAE/g fw) and TAC methods DPPH (4,352 µmolTE/g fw), FRAP (8,773 µmolTE/g fw) and CUPRAC (25,757 µmolTE/g fw) were extraction time of 15 minutes, particle size of 100 mesh, solid-solvent ratio of 1:20 g/mL, and ethanol concentration of 88%. Under these conditions, the experimental values of TPC were 1.32 mg GAE/g fw, TAC-DPPH 3.23 µmolTE/g fw, TAC-FRAP 6.54 µmolTE/g fw, and TAC-CUPRAC 25.59 µmolTE/g fw. Overall, the findings of this study demonstrate the success of RSM in optimizing the extraction conditions of phenolic and antioxidant compounds from CCL seeds.