Chemistry Department, University of Rome La Sapienza, 00185 Rome, Italy.
CIABC, University of Rome La Sapienza, 00185 Rome, Italy.
Molecules. 2019 Jul 16;24(14):2581. doi: 10.3390/molecules24142581.
In recent years, great attention has been focused on rapid, selective, and environmentally friendly extraction methods to recover pigments and antioxidants from microalgae. Among these, supercritical fluid extraction (SFE) represents one of the most important alternatives to traditional extraction methods carried out with the use of organic solvents. In this study, the influence of parameters such as pressure, temperature, and the addition of a polar co-solvent in the SFE yields of carotenoids and fat-soluble vitamins from biomass were evaluated. The highest extraction of alpha-tocopherol, gamma-tocopherol, and retinol was achieved at a pressure of 30 MPa and a temperature of 40 °C. It was observed that overall, the extraction yield increased considerably when a preliminary step of sample pre-treatment, based on a matrix solid phase dispersion, was applied using diatomaceous earth as a dispersing agent. The use of ethanol as a co-solvent, under certain conditions of pressure and temperature, resulted in selectively increasing the yields of only some compounds. In particular, a remarkable selectivity was observed if the extraction was carried out in the presence of ethanol at 10 MPa and 40 °C: under these conditions, it was possible to isolate menaquinone-7, a homologous of vitamin K2, which, otherwise, cannot not recovered by using traditional extraction procedures.
近年来，人们高度关注快速、选择性强且环境友好的提取方法，以从微藻中回收色素和抗氧化剂。在这些方法中，超临界流体萃取（SFE）是替代传统有机溶剂提取方法的最重要方法之一。在这项研究中，评估了参数（如压力、温度和添加极性共溶剂）对从生物质中提取类胡萝卜素和脂溶性维生素的 SFE 产率的影响。在压力为 30 MPa 和温度为 40°C 的条件下，可实现 α-生育酚、γ-生育酚和视黄醇的最高提取率。观察到，总体而言，当应用基于基质固相分散的样品预处理初步步骤时，使用硅藻土作为分散剂，提取产率大大增加。在一定的压力和温度条件下，使用乙醇作为共溶剂导致仅选择性地增加了某些化合物的产率。特别是，如果在 10 MPa 和 40°C 的乙醇存在下进行提取，则可以观察到显著的选择性：在这些条件下，可以分离出维生素 K2 的同系物menaquinone-7，而使用传统提取程序则无法回收该物质。
