Optimization of Phenolic Compounds Extraction and Antioxidant Activity from Inonotus hispidus Using Ultrasound-Assisted Extraction Technology.

The use of ultrasound-assisted extraction (UAE) of bioactive compounds has been increasing because it is a good alternative to the conventional extraction methods. UAE was used to maximize total polyphenol content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity, and ferric reducing antioxidant power (FRAP) of the mushroom using response surface methodology (RSM). Firstly, the effect of 40% (/) ethanol and 80% (/) methanol on the TPC, DPPH scavenging capacity, and FRAP was evaluated. The ethanolic extracts showed a significantly higher ( < 0.0001) TPC, DPPH scavenging capacity, and FRAP than the methanolic extracts. The best condition to produce an extract with the higher TPC and antioxidant activity was achieved when using 40% (/) ethanol, a ratio of 75 mL/g, and an extraction time of 20 min. The chromatographic profile of the extract obtained in the optimized condition revealed that hispidin is the main polyphenol present in the extracts of , representing, together with hispidin-like compounds, the majority of the phenolic compounds (159.56 µg/g DW out of 219.01 µg/g DW). The model allowed us to optimize the conditions to maximize the extraction of phenolic compounds with antioxidant activity from , demonstrating its potential as a source of antioxidant compounds, with possible industrial, pharmaceutical, and food applications.