Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, SI-6000 Koper, Slovenia.
The Biocomposites Centre, Bangor University, Bangor, Gwynedd LL57 2DG, UK.
Molecules. 2020 Dec 22;26(1):7. doi: 10.3390/molecules26010007.
The valorization of olive pomace through the extraction of phenolic compounds at an industrial scale is influenced by several factors that can have a significant impact on the feasibility of this approach. These include the types and levels of phenolic compounds that are present, the impact that seasonal variation and cultivar type have on the phenolic compound content in both olive pomace and mill effluents and the technological approach used to process the olive crop. Chemical analysis of phenolic compounds was performed using an HPLC-diode-array detector (DAD)-qTOF system, resulting in the identification of 45 compounds in olive mill wastewater and pomace, where secoiridoids comprised 50-60% of the total phenolic content. This study examined three different factors that could impact the phenolic compound content of these processing streams, including cultivar types typically grown on local farms in Slovenia, the type of downstream processing used and seasonality effects. Olive crop varieties sourced from local farms showed high variability, and the highest phenolic content was associated with the local variety "Istrska Belica". During processing, the phenolic content was on average approximately 50% higher during two-phase decanting compared to three-phase decanting and the type of compound present significantly different. An investigation into the seasonal effects revealed that the phenolic content was 20% higher during the 2019 growing season compared to 2018. A larger sample size over additional growing seasons is required to fully understand the annual variation in phenolic compound content. The methods and results used in this study provide a basis for further analysis of phenolic compounds present in the European Union's olive crop processing residues and will inform techno-economic modelling for the development of olive biorefineries in Slovenia.
橄榄废渣中酚类化合物的提取和工业化利用受到多种因素的影响，这些因素可能会显著影响该方法的可行性。这些因素包括酚类化合物的类型和水平、季节性变化和品种类型对橄榄废渣和轧出液中酚类化合物含量的影响，以及用于加工橄榄作物的技术方法。采用 HPLC-二极管阵列检测器（DAD）-qTOF 系统对酚类化合物进行化学分析，鉴定出橄榄油厂废水中有 45 种化合物，其中 50-60%为二萜类化合物。本研究考察了三种不同因素对这些加工流中酚类化合物含量的影响，包括在斯洛文尼亚当地农场种植的典型品种、下游加工类型和季节性效应。来自当地农场的橄榄作物品种表现出高度的可变性，最高的酚类含量与当地品种“伊斯特斯卡·贝尔卡”有关。在加工过程中，两相分相比三相分相的平均酚类含量高约 50%，且存在的化合物类型显著不同。对季节性影响的调查表明，2019 年生长季节的酚类含量比 2018 年高 20%。需要在更多的生长季节收集更大的样本量，以充分了解酚类化合物含量的年度变化。本研究中使用的方法和结果为进一步分析欧盟橄榄作物加工残渣中存在的酚类化合物提供了基础，并将为斯洛文尼亚橄榄生物精炼厂的开发提供技术经济建模依据。
