title: Pectin from Abelmoschus esculentus: optimization of extraction and rheological properties.
abstract: Response surface methodology (RSM) was applied to optimize the parameters of pectin extraction from okra pods. The extracted okra pectin was then investigated by steady-shear and oscillatory rheological measurements. Statistical analysis showed that the linear term of the liquid-solid ratio, the quadratic term of the pH, and the linear term of the extraction time showed highly significant effects on pectin yield. The optimal extraction conditions that maximized the pectin yield within the experimental range of the variables researched were a pH of 3.9, an extraction time of 64 min, an extraction temperature of 60°C, and a liquid-solid ratio of 42:1. Under these conditions, the pectin yield was predicted to be 2.71%. At a liquid-solid ratio less than 2.5% w/w in aqueous solution, the pectin extracted from okra presented non-Newtonian shear-thinning behavior and could be well described by the Cross model. The okra pectin showed predominantly viscous responses (G'<G″) over a wide range of frequencies (10(-1)-10 Hz) at 20% strain.
authors: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China.
authors: Yi
authors: Y
authors: Chen
authors: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China.
authors: Jian-Guo
authors: JG
authors: Zhang
authors: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China.
authors: Han-Ju
authors: HJ
authors: Sun
authors: School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China. Electronic address: zjwei@hfut.edu.cn.
authors: Zhao-Jun
authors: ZJ
authors: Wei
mesh_terms: D028483:Abelmoschus / Q000737:chemistry*; D008970:Molecular Weight; D010368:Pectins / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D012212:Rheology; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014783:Viscosity
chemical_list: D010936:Plant Extracts; D010368:Pectins
keywords: Okra pectin; Optimal extraction; Response surface methodology; Rheological behavior