Ultrasound-assisted extraction of mycosterols from Agaricus bisporus L. vs conventional Soxhlet extraction

• Autor(a) principal: Diz, Patrícia do Carmo Claro
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/12426

Ergosterol is the most abundant mycosterol in Agaricus bisporus L. (cultivated mushroom most consumed worldwide) and has high commercial value since, among other applications; it is used by the pharmaceutical industry in the preparation of several drugs. To replace common conventional extraction techniques (e.g. Soxhlet), the present study reports the optimal ultrasound-assisted extraction conditions for ergosterol. After preliminary tests, the results showed that the type of solvent, extraction time and ultrasound power alter notably the extraction efficiency. Using response surface methodology, models were developed to investigate the favourable experimental conditions that maximize the extraction efficiency. All the statistical criteria demonstrated the validity of the proposed models. Overall, ultrasound-assisted extraction with ethanol at 375 W during 15 min proved to be as efficient as the Soxhlet extraction, yielding 671.5±0.5 mg ergosterol/100 g dw. However, n-hexane conducted to extracts with higher purity (mg ergosterol/g extract) due to the high affinity for lipophilic compounds. In this work it was also concluded that, to simplify the extraction process under industrial conditions, the saponification step often done in the purification of sterol extracts, can be eliminated, without significant differences in the ergosterol content.