Mao Yujie, Lei Rui, Ryan John, Arrutia Rodriguez Fatima, Rastall Bob, Chatzifragkou Afroditi, Winkworth-Smith Charles, Harding Stephen E, Ibbett Roger, Binner Eleanor
Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, University Park, NG7 2RD, UK.
Department of Food and Nutritional Sciences, University of Reading, PO Box 226, 13 Whiteknights, Reading RG6 6AP, UK.
Food Chem X. 2019 Jun 30;2:100026. doi: 10.1016/j.fochx.2019.100026.
Sugar beet pectin is rich in rhamnogalacturonan-I (RG-I) region, which is a potential source of prebiotics. RG-I pectin cannot be extracted the same way as commercial homogalacturan-rich pectin using hot acid. Therefore, this study has explored several alternative methods, including microwave-assisted extraction (MAE) and conventional-solvent extraction (CSE) at atmospheric pressure using different solvents, and microwave-assisted hydrothermal extraction (MAHE) under pressure using water. No conclusive differences in microwave and conventional heating were found with heating rate controlled. The optimum treatment times of both MAE and CSE at 90 °C atmospheric pressure and regardless of the solvents used were 120 min; however, MAHE at 130 °C under pressure can dramatically reduce the time to 10 min. Alcohol-insoluble solids (AIS) extracted using pH13 solvent by MAE had both the highest RG-I yield at 25.3% and purity at 260.2 mg/g AIS, followed by AIS extracts using water by MAHE with 7.5% and 166.7 mg/g AIS respectively.
甜菜果胶富含鼠李半乳糖醛酸聚糖-I（RG-I）区域，该区域是益生元的潜在来源。RG-I果胶无法像使用热酸提取富含同型半乳糖醛酸聚糖的商业果胶那样的方式进行提取。因此，本研究探索了几种替代方法，包括微波辅助提取（MAE）和在常压下使用不同溶剂的常规溶剂提取（CSE），以及在压力下使用水的微波辅助水热提取（MAHE）。在控制加热速率的情况下，未发现微波加热和传统加热有决定性差异。在90°C常压下，无论使用何种溶剂，MAE和CSE的最佳处理时间均为120分钟；然而，在130°C压力下的MAHE可将时间大幅缩短至10分钟。通过MAE使用pH13溶剂提取的醇不溶性固体（AIS）的RG-I产量最高，为25.3%，纯度为260.2 mg/g AIS，其次是通过MAHE使用水提取的AIS提取物，分别为7.5%和166.7 mg/g AIS。
