Quoc Le Pham Tan, Muoi Nguyen Van
Department of Food Technology, Can Tho University, Vietnam.
Institute of Biotechnology and Food Technology, Industrial University of Ho Chi Minh City, Vietnam.
Acta Sci Pol Technol Aliment. 2016 Apr-Jun;15(2):181-189. doi: 10.17306/J.AFS.2016.2.18.
The aim of this study was to determine the best extraction conditions for total phenolic content (TPC) and antioxidant capacity (AC) of Polygonum multiflorum Thunb. root using microwave-assisted extraction (MAE).
The raw material used was Polygonum multiflorum Thunb. root powder. Five factors such as solvent type, solvent concentrations, solvent/material ratio, extraction time and microwave power were studied; TPC and AC values were determined by the Folin-Ciocalteu method and DPPH free radical scavenging activity measurement, respectively. In addition, studies involved assaying the HPLC test of extracts and SEM of samples.
Optimal results pointed to acetone as the solvent, acetone concentration of 60%, solvent/material ratio of 40/1 (v/w), extraction time of 5 mins and microwave power of 127 W. TPC and AC obtained were approximates 44.3 ±0.13 mg GAE/g DW and 341.26 ±1.54 μmol TE/g DW, respectively. The effect of microwaving on the cell destruction of Polygonum multiflorum Thunb. root was observed by scanning electron microscopy (SEM). Some phenolic compounds were determined by the HPLC method, for instance, gallic acid, catechin and resveratrol.
These factors significantly affected TPC and AC. We can use acetone as a solvent with microwave-assisted extraction to achieve the best result.
本研究的目的是确定使用微波辅助萃取（MAE）法提取何首乌根中总酚含量（TPC）和抗氧化能力（AC）的最佳萃取条件。
所用原料为何首乌根粉。研究了溶剂类型、溶剂浓度、溶剂/物料比、萃取时间和微波功率这五个因素；分别采用福林-酚法和DPPH自由基清除活性测定法测定TPC和AC值。此外，研究还包括对提取物进行高效液相色谱（HPLC）检测以及对样品进行扫描电子显微镜（SEM）分析。
最佳结果表明，溶剂为丙酮，丙酮浓度为60%，溶剂/物料比为40/1（v/w），萃取时间为5分钟，微波功率为127瓦。所获得的TPC和AC分别约为44.3±0.13毫克没食子酸当量/克干重和341.26±1.54微摩尔 Trolox 当量/克干重。通过扫描电子显微镜（SEM）观察了微波对何首乌根细胞破坏的影响。采用HPLC法测定了一些酚类化合物，例如没食子酸、儿茶素和白藜芦醇。
这些因素对TPC和AC有显著影响。我们可以使用丙酮作为溶剂并结合微波辅助萃取以获得最佳效果。
