Chemical Engineering Department, Escola d'Enginyeria de Barcelona Est (EEBE), Universitat Politècnica de Catalunya (UPC)-BarcelonaTECH, C/ Eduard Maristany 10-14, Campus Diagonal-Besòs, 08930 Barcelona, Spain; Barcelona Research Center for Multiscale Science and Engineering, Campus Diagonal-Besòs, 08930 Barcelona, Spain.
CINTECX, University of Vigo, Chemical Engineering Department, 36310 Vigo, Spain.
Sci Total Environ. 2022 Aug 20;835:155552. doi: 10.1016/j.scitotenv.2022.155552. Epub 2022 Apr 27.
The aim of this study was to evaluate the recovery of phenolic compounds from olive mill and winery wastes by conventional solid-liquid extraction (SLE) using water as the extraction solvent. The studied variables were extraction time (5-15 min), temperature (25-90 °C), solid-to-liquid ratio (1:10-1:100 (kg/L)), pH (3-10) and application of multiple extractions (1-3). The extraction efficiency was evaluated in terms of total phenolic content (TPC), determined by high performance liquid chromatography (HPLC-UV), but also from the recovery of some representative phenolic compounds. The optimized conditions were one extraction step, 10 min, 25 °C, 1:30 (kg/L), pH 5 for olive pomace, and one extraction step, 10 min, 70 °C, 1:100 (kg/L), pH 5 for winery residues. The extraction method is simple and suitable for scaling-up in industry, and the aqueous extracts are fully compatible with further purification schemes based on the use of membranes or resins. The optimized technique was applied to a set of different representative residues from olive mill and winery industries, to assess their suitability as sources for phenolic compounds recovery. The phenolic content in the extracts was evaluated by chromatographic analysis and by the Folin-Ciocalteu assay (FC). Furthermore, the antioxidant capacity was determined by 2,2-azinobis-3-etilbenzotiazolina-6-sulfonat (ABTS), 2,-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Because of their high contents in phenolic compounds and great antioxidant capacity, olive pomace and lees filters were identified as especially suited sources for phenolic compounds recovery.
本研究旨在评估采用水作为提取溶剂的常规固液萃取（SLE）从橄榄厂和酿酒厂废物中回收酚类化合物的情况。研究的变量包括提取时间（5-15 分钟）、温度（25-90°C）、固液比（1:10-1:100（kg/L））、pH 值（3-10）和多次提取的应用（1-3）。通过高效液相色谱（HPLC-UV）测定总酚含量（TPC）来评估提取效率，同时还评估了一些代表性酚类化合物的回收情况。优化条件为橄榄渣的一次提取步骤，10 分钟，25°C，固液比 1:30（kg/L），pH 值 5；酿酒厂残渣的一次提取步骤，10 分钟，70°C，固液比 1:100（kg/L），pH 值 5。该提取方法简单，适合工业放大，水提物完全可与基于膜或树脂使用的进一步纯化方案兼容。优化后的技术应用于一组来自橄榄厂和酿酒厂的不同代表性残渣，以评估它们作为酚类化合物回收来源的适用性。通过色谱分析和福林-肖卡尔特（Folin-Ciocalteu）测定法（FC）评估提取物中的酚含量。此外，通过 2,2-偶氮双-3-乙基苯并噻唑啉-6-磺酸（ABTS）、2,2-二苯基-1-苦基肼（DPPH）和铁还原抗氧化能力（FRAP）测定法测定抗氧化能力。由于橄榄渣和酒糟过滤器中酚类化合物含量高，抗氧化能力强，因此被确定为特别适合酚类化合物回收的来源。
