The strawberry tree (Arbutus unedo) is an evergreen plant belonging to the Ericaceae family, an endemic specie of the Mediterranean. In Portugal it grows mostly wild and its fruits are mainly used to produce a distillated alcoholic beverage called “Aguardente de Medronho”. From the process, a residue is obtained which is normally discarded, despite it may figure as biomass for valorization.

This work intends to study different conditions of supercritical fluid extraction (SFE), using carbon dioxide as solvent and ethanol as co-solvent for the recovery of bioactive compounds from that residue. After a screening design of experiments varying pressure, temperature, co-solvent, flow rate and time of extraction, an optimization design of experiments (central composite design) was performed. Time (90 min) and flow rate (10 g/min) were established. Variables were pressure (100, 200 and 300 bar), temperature (35, 45 and 55 °C) and co-solvent concentration (0, 10 and 20 %). Extracts were analyzed by GC–MS and LC–MS/MS and cytotoxicity and antiproliferative effect of the extracts was evaluated in Caco2 and HT-29 cell models respectively. Chemical characterization showed an increase in phenolic compounds such as pyrogallol, gallic acid, catechol and protocatechuic acid amongst others, with the increase of the co-solvent. GC–MS analysis revealed a diversity of compounds from fatty acid esters, terpenes and small molecules with recognized bioactivity. The most promising extract was obtained using 300 bar and 55 °C and 20 % of co-solvent. Besides being the extract with the highest yield, it also presented the lowest EC50 (0.569 mg/mL) mainly due to the presence of phenolic compounds.

草莓树（Arbutus unedo）是属于Ericaceae属的常绿植物，属于地中海的特有物种。在葡萄牙，它主要是野生的，其果实主要用于生产称为“ Aguardente de Medronho”的蒸馏酒精饮料。从该方法中，获得残余物，该残余物通常被丢弃，尽管其可能被视为用于增值的生物质。

这项工作旨在研究超临界流体萃取（SFE）的不同条件，以二氧化碳为溶剂，乙醇为助溶剂，从残留物中回收生物活性化合物。在对压力，温度，助溶剂，流速和萃取时间进行变化的实验筛选设计之后，进行了实验的优化设计（中央复合设计）。确定时间（90分钟）和流速（10 g / min）。变量为压力（100、200和300 bar），温度（35、45和55°C）和助溶剂浓度（0％，10％和20％）。通过GC-MS和LC-MS / MS分析提取物，并分别在Caco2和HT-29细胞模型中评估提取物的细胞毒性和抗增殖作用。化学表征表明，诸如邻苯三酚，没食子酸，儿茶酚和原儿茶酸等，随着助溶剂的增加。GC-MS分析表明，脂肪酸酯，萜烯和小分子等多种化合物具有公认的生物活性。最有希望的提取物是在300 bar和55°C和20％的助溶剂下获得的。除了是最高产量的提取物外，它的EC50也最低（0.569 mg / mL），这主要是由于酚类化合物的存在。