title: Optimization of subcritical water extraction of polysaccharides from Grifola frondosa using response surface methodology.
abstract: BACKGROUND
  This research is among the few that has been conducted on the feasibility of subcritical water extraction (SWE) as a rapid and efficient extraction tool for polysaccharides.
  
  
  OBJECTIVE
  The aim of the study was to extractand optimize the parameter conditions of SWE of polysaccharides from Grifola frondosa using response surface methodology.
  
  
  METHODS
  In the study, SWEwas applied to extractbioactive compounds from G. frondosa. A preliminary analysis was made on the physical properties and content determination of extracts using SWE and hot water extraction (HWE). Analysis of the sample residues and antioxidant activities of the polysaccharides extracted by SWE and HWE were then evaluated.
  
  
  RESULTS
  THE OPTIMAL EXTRACTION CONDITIONS INCLUDE: extraction temperature of 210°C, extraction time of 43.65 min and the ratio of water to raw material of 26.15:1. Under these optimal conditions, the experimental yield of the polysaccharides (25.1 ± 0.3%) corresponded with the mean value predicted by the model and two times more than the mean value obtained by the traditional HWE. The antioxidant activities of polysaccharides extracted by SWE were generally higher than those extracted by HWE. From the study, the SWE technology could be a time-saving, high yield, and bioactive technique for production of polysaccharides.
authors.affiliation: Department of Applied Chemistry, School of Chemistry and Chemical Engineering, Jiangsu University, 301 Xuefu Rd., Zhenjiang, Jiangsu, China.
authors.forename: Liuqing
authors.initials: L
authors.lastname: Yang
authors.forename: Hongyuan
authors.initials: H
authors.lastname: Qu
authors.forename: Guanghua
authors.initials: G
authors.lastname: Mao
authors.forename: Ting
authors.initials: T
authors.lastname: Zhao
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Bole
authors.initials: B
authors.lastname: Zhu
authors.forename: Bingtao
authors.initials: B
authors.lastname: Zhang
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Wu
keywords: Antioxidant activity; Grifola frondosa; polysaccharide; response surface methodology; subcritical water extraction