Optimization of ergosterol extraction from Pleurotus mushrooms using response surface methodology (RSM)

Pleurotus genus represents one of the most widely consumed mushrooms in the world with interesting healthpromoting benefits, mainly due to their richness in several bioactive compounds [1]. Mushrooms produce ergosterol as one of their main sterols, which has been considered a contributor to their anti-inflammatory, antioxidant, and antitumor properties [2]. Obtaining an ergosterol enriched extract depends on different variables, such as the extraction method, solvent type, temperature, extraction time, and the solid-liquid ratio [2]. Therefore, it is essential to define the main variables and relevant response criteria to maximize the extraction yield and purity, taking into account cost functions. In the present work, response surface methodology (RSM) was applied to optimize a heat assisted extraction system (HAE), combining time (t) and temperature (T) effects, and using a circumscribed central composite design (CCCD) for the recovery of ergosterol from the fruiting bodies of P. ostreatus and P. eryngii produced with lignocellulose substrate. Both mushrooms (POG and PEG for P. ostreatus and P. eryngii) and their byproduct (POR and PER for P. ostreatus and P. eryngii) were used in the present work. The obtained responses were the quantification of ergosterol by HPLC-UV (Y1: mg of ergosterol per g of extract residue and Y2: mg of ergosterol per 100 g of dry weight mushroom).The authors are grateful to FCT, Portugal and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2019); European Regional Development Fund (ERDF) within the scope of project MicoBioExtract (POCI-01- 0247-FEDER- 033939); European Agricultural Fund for Rural Development (EAFRD), through the Rural Development Program (PDR2020), within the scope of Project MicoCoating (PDR2020-101-031472); European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project Mobilizador ValorNatural®; L. Barros. thanks the national funding by FCT, P.I., through the institutional scientific employment program-contract for her contract.