Antioxidative properties of Diplazium Esculentum extract by using pressurized hot water extractor: optimization study

Pressurized hot water extraction (PHWE) was implemented in attempt to reduce the use of toxic organic solvent in extracting bioactive compounds from Diplazium esculentum. Comparison extraction methods were done and the results shows that the PHWE had higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity (70%) and total phenolic contents (118.83f.lg catechin equivalentlmg dry samples) c,.ompared to autoclaving, boiling, soaking, sonicating and Soxhlet extraction. Soaking extraction had the highest total flavonoids contents (28.03f.lg rutin equivalentlmg dry extract). By applying Box-Behnken design of response surface methodology, the optimized condition for the best antioxidant activity of PH WE was at 17SoC, 21 minutes extraction time and SOmL water volume added to 2g of dried ground D. esculentum. The DPPH antiradical efficiency was analyzed where the D. esculentum extracts had ECso value of 1241.14f.lg/mL and time to reach steady state (TEC50) was 79.83 minutes. Thus, the extract was categorized as slow in scavenging the DPPH free radicals. Through HPLC, the identified flavonoids in the crude extracts were quercetin and myricetin.