In this study, extraction yield of valuable compounds from brewer’s spent grain (BSG) using pressurized liquid extraction (PLE) was investigated varying temperature, solvent type, and flow rate at a constant pressure. The results were compared with Soxhlet extractions using the total phenolic compounds (TPC), total flavonoid compounds (TFC), antioxidant activity (AA), reducing sugars (RS), and total reducing sugars (TRS) as indices. The highest PLE extraction yield was 20.1 wt%, at 120 °C, 2 mL/min using ethanol to water volume ratio of 0.5, at 10 MPa. The TPC, TFC, and AA content were favored by water and water/ethanol extractions and temperature increase. The highest AA was obtained with water at 120 °C and 4 mL/min achieving 9944, 4769 and 4096 µmol TE/100 g of BSG extract, respectively. PLE was capable of present high extraction yields maintaining the RS and TRS in the BSG matrix. In addition, BSG was defatted with compressed propane before the extraction with PLE, showing that compressed propane is highly efficient in recovering the lipid fraction from BSG. The results demonstrated a great potential of water and different EtOH/Water solvent ratio at pressurized conditions for obtaining bio-compounds of BSG in a crude extract with expressive biological activity.

在这项研究中，研究了使用加压液体萃取 (PLE) 从啤酒糟 (BSG) 中提取有价值的化合物的产率，研究了在恒定压力下改变温度、溶剂类型和流速。使用总酚类化合物 (TPC)、总黄酮类化合物 (TFC)、抗氧化活性 (AA)、还原糖 (RS) 和总还原糖 (TRS) 作为指标，将结果与索氏提取物进行比较。最高的 PLE 提取率为 20.1 wt%，120 °C，2 mL/min，乙醇与水的体积比为 0.5，压力为 10 MPa。TPC、TFC 和 AA 含量受水和水/乙醇萃取以及温度升高的青睐。使用 120 °C 和 4 mL/min 的水获得最高 AA，分别达到 9944、4769 和 4096 µmol TE/100 g BSG 提取物。PLE 能够保持 BSG 矩阵中的 RS 和 TRS 的高提取率。此外，在用 PLE 提取之前，BSG 用压缩丙烷脱脂，表明压缩丙烷在从 BSG 中回收脂质部分方面非常有效。结果表明，在加压条件下，水和不同 EtOH/水溶剂比在获得具有表达生物活性的粗提取物中的 BSG 生物化合物方面具有巨大潜力。