REQUIMTE/LAQV, Department of Chemical Sciences, Faculty of Pharmacy, University of Porto, R. J. Viterbo, 4050-313 Porto, Portugal.
Centre for Micro-Electro Mechanical Systems, University of Minho, 4800-058 Guimarães, Portugal.
Sci Total Environ. 2018 Dec 10;644:229-236. doi: 10.1016/j.scitotenv.2018.06.350. Epub 2018 Jul 5.
Olive pomace is a major output of olive oil processing. This by-product is a valuable source of bioactive compounds with well-recognized benefits for human health and well-being. In this work, the proximate composition and the profiles of vitamin E (HPLC-DAD-FLD), fatty acids (GC-FID) and phenolics (HPLC-DAD-FL/MS) were determined. Additionally, a sustainable process for antioxidants extraction - Multi-frequency Multimode Modulated (MMM) ultrasonic technique - was compared to a conventional solid-liquid extraction. The total phenolics content and antioxidant activity (ferric reducing antioxidant power and DPPH scavenging ability) of the extracts were analysed to assess the efficacy of both extraction methodologies. The vitamin E profile of the olive pomace comprised the vitamers α-tocopherol, β-tocopherol, α-tocotrienol and γ-tocopherol. α-Tocopherol was the major form (2.63 mg/100 g), while the other vitamers were present in amounts lower than 0.1 mg/100 g. The lipid fraction was especially rich in oleic acid (75%), followed by palmitic (10%), linoleic (9%), and stearic (3%) acids. Hydroxytyrosol and comsegoloside represented ≈79% of the total phenolics present in olive pomace. Hydroxytyrosol content was 83.6 mg/100 g, while tyrosol was present in lower amounts (3.4 mg/100 g). Concerning the antioxidants extraction, the MMM technique allowed a faster and higher recovery (p < 0.05) of the compounds, compared to the conventional solid-liquid extraction. By this way, it seems to be a very promising eco-friendly and effective methodology to extract antioxidants from this and other matrices.
橄榄渣是橄榄油加工的主要副产品。这种副产物是生物活性化合物的宝贵来源，对人类健康和福祉有公认的益处。在这项工作中，测定了其近似成分和维生素 E（HPLC-DAD-FLD）、脂肪酸（GC-FID）和酚类物质（HPLC-DAD-FL/MS）的含量。此外，还比较了一种可持续的抗氧化剂提取工艺——多频多模调制（MMM）超声技术与传统的固液提取。通过分析提取物的总酚含量和抗氧化活性（铁还原抗氧化能力和 DPPH 清除能力）来评估这两种提取方法的效果。橄榄渣的维生素 E 组成包括生育酚 α-、β-、α-三烯醇和 γ-生育酚。α-生育酚是主要形式（2.63mg/100g），而其他生育酚的含量低于 0.1mg/100g。脂质部分特别富含油酸（75%），其次是棕榈酸（10%）、亚油酸（9%）和硬脂酸（3%）。羟基酪醇和酪醇苷约占橄榄渣中总酚类物质的 79%。羟基酪醇含量为 83.6mg/100g，而酪醇的含量较低（3.4mg/100g）。关于抗氧化剂的提取，与传统的固液提取相比，MMM 技术能够更快、更高效地回收（p<0.05）化合物。通过这种方式，它似乎是一种非常有前途的环保和有效的方法，可以从这种和其他基质中提取抗氧化剂。
