Optimization of Diplazium Esculentum Extract Using Pressurized Hot Water Extractor by Box-Behnken Design of Experiments and Its Antioxidative Behavior

Pressurized hot water extraction (PHWE) was implemented in attempt to reduce the use of toxic organic solvent in extracting bioactive compounds from Diplazium esculentum. The antioxidant assays, which were the DPPH scavenging activity, total phenolic contents and total flavonoid contents were analyzed on PHW extracts. By applying Box-Behnken design under response surface methodology (RSM), the optimized condition for the best antioxidant activity of PHWE was at 175 °C, 21 min extraction time and 50 mL water volume added to 2 g of dried D. esculentum. The DPPH antiradical efficiency of D. esculentum give EC₅₀ values of 1241.14 μg/mL and time to reach steady state (T_EC50) was 79.83 min. Thus, the extract was categorized as slow in scavenging the DPPH free radicals. (paper)