Getachew Adane Tilahun, Chun Byung Soo
Department of Food Science and Technology, Pukyong National University, 45 Yongso-ro, Nam-Gu, Busan, 48513, Republic of Korea; School of Chemical and Bioengineering, Addis Ababa Institute of Technology, Addis Ababa University, P. O. Box 385, Addis Ababa, Ethiopia.
Department of Food Science and Technology, Pukyong National University, 45 Yongso-ro, Nam-Gu, Busan, 48513, Republic of Korea.
Int J Biol Macromol. 2017 Jun;99:555-562. doi: 10.1016/j.ijbiomac.2017.03.034. Epub 2017 Mar 7.
Polysaccharides are an abundant resource in coffee beans and have proved to show numerous bioactivities. Despite their abundance, their activities are not always satisfactory mostly due to their structure and large molecular size. Molecular modifications of native polysaccharides can overcome this problem. In this study, we used a novel and green method to modify native coffee polysaccharides using subcritical water (SCW) treatment. The SCW treatment was used at the temperature of 180°C-220°C and pressure of 30-60bar. The molecular and structural modification of the polysaccharides was confirmed using several techniques such as FT-IR, UV spectroscopy, XRD, and TGA. The antioxidant activity of the modified polysaccharides was evaluated using several chemical and Saccharomyces cerevisiae-based high throughput assays. The modified polysaccharides showed high antioxidant activities in all tested assays. Moreover, the polysaccharides showed high DNA protection activities. Therefore, SCW could be employed as a green solvent for molecular modification of polysaccharides.
多糖是咖啡豆中丰富的资源，已被证明具有多种生物活性。尽管它们含量丰富，但由于其结构和大分子尺寸，其活性并不总是令人满意。天然多糖的分子修饰可以克服这个问题。在本研究中，我们使用了一种新颖的绿色方法，通过亚临界水（SCW）处理来修饰天然咖啡多糖。SCW处理在180°C - 220°C的温度和30 - 60bar的压力下进行。使用傅里叶变换红外光谱（FT - IR）、紫外光谱、X射线衍射（XRD）和热重分析（TGA）等多种技术证实了多糖的分子和结构修饰。使用几种基于化学和酿酒酵母的高通量测定方法评估了修饰多糖的抗氧化活性。修饰后的多糖在所有测试测定中均表现出高抗氧化活性。此外，这些多糖还表现出高DNA保护活性。因此，SCW可作为多糖分子修饰的绿色溶剂。
