The sequential extraction of spent coffee grounds (SCG) oil by compressed propane and butane (CPE and CBE) followed by the extraction of phenolic compounds by supercritical CO (scCO) plus solvent was studied. Extraction with CPE and CBE at different conditions of pressure (2 – 10 MPa), temperature (40 – 80 ˚C), particle size (0.356 and 0.867 mm), static extraction time (0, 10, 30 and 60 min), dynamic extraction time (25 and 60 min) and solvent flow rate (1, 2 and 3 g/min) reached the maximum extraction yield around 11.5 wt%, and with similar overall extraction curves. The second step of extraction with scCO+EtOH (2:1) increased the recovery of phenolics (expressed as GAE, gallic acid equivalent) from 0.9 mg GAE/g (single-step extraction scCO+EtOH (2:1) to 3.88 mg GAE/g (second step of sequential extraction). The results showed the technical feasibility of the extraction of oil and phenolic extracts by the studied approach.

中文翻译：

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使用压缩丙烷/丁烷从用过的咖啡渣中回收有价值的化合物，然后进行 SCCO2 加溶剂萃取


研究了用压缩丙烷和丁烷（CPE 和 CBE）顺序萃取废咖啡渣 (SCG) 油，然后用超临界 CO (scCO) 加溶剂萃取酚类化合物。在不同压力（2 – 10MPa）、温度（40 – 80 ℃）、粒径（0.356 和 0.867mm）、静态萃取时间（0、10、30 和 60 分钟）、动态条件下用 CPE 和 CBE 萃取萃取时间（25和60分钟）和溶剂流速（1、2和3g/min）达到最大萃取率约11.5wt%，且总体萃取曲线相似。第二步 scCO+EtOH (2:1) 萃取将酚类物质的回收率（以 GAE 表示，没食子酸当量）从 0.9mg GAE/g（单步萃取 scCO+EtOH (2:1)）提高到 3.88mg GAE/g（连续提取的第二步）结果表明通过所研究的方法提取油和酚提取物的技术可行性。