title: [Optimal extraction of polysaccharide from Dioscorea nipponica by central composite design and response surface methodology].
abstract: OBJECTIVE
  To optimize the extracting technology for polysaccharides from Dioscorea nipponica by response surface methodology.
  
  
  METHODS
  The independent variables were extraction temperature, reflux time and liquid-to-solid ratio, the dependent variable was extraction rate of polysaccharides in Dioscorea nipponica. Linear or nonlinear mathematic models were used to estimate the relationship between independent and dependent variables. Central composite design and response surface methodology were used to optimize the process of extraction. The prediction was carried out through comparing the observed and predicted values.
  
  
  RESULTS
  The optimum technological parameters were as follows: extraction temperature 91.5° C, reflux time 172.9 min, solid-to-liquid ratio 25.8:1 and 2 times for extraction. Bias between observed and predicted of rates was 1.3%.
  
  
  CONCLUSIONS
  The extraction technology is simple, reliable and highly predictive.
authors.affiliation: Liaoning University of Traditional Chinese Medicine, Dalian 116600, China. wstczxs@163.com
authors.forename: Nan
authors.initials: N
authors.lastname: Zhang
authors.forename: Ting-guo
authors.initials: TG
authors.lastname: Kang
authors.forename: Hai-bo
authors.initials: HB
authors.lastname: Yin
mesh_terms: D027742:Dioscorea / Q000737:chemistry*; D000431:Ethanol / Q000008:administration & dosage / Q000737:chemistry; D016014:Linear Models; D010946:Plants, Medicinal / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification*; D015203:Reproducibility of Results; D027343:Rhizome / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013678:Technology, Pharmaceutical / Q000379:methods*; D013696:Temperature; D013997:Time Factors
chemical_list: D011134:Polysaccharides; D012997:Solvents; D000431:Ethanol