title: Optimization of ultrasonic-assisted extraction of antioxidant polysaccharides from the stem of Trapa quadrispinosa using response surface methodology.
abstract: Response surface methodology (RSM) was used to optimize experimental conditions for ultrasonic-assisted extraction (UAE) of antioxidant crude polysaccharides (CPS) from Trapa quadrispinosa stems. Antioxidant capacity of polysaccharides was determined by Ferric-Reducing Antioxidant Capacity (FRAC) assay with the method of 1, 10-phenanthroline. The maximum yield of polysaccharides (2.78±0.16%) was obtained under optimal extraction conditions of extraction time, 41min; ratio of water to material, 31.5mL/g; and extraction temperature, 58°C. The maximum antioxidant capacity (19.02±0.24μmol Fe2+/g) was obtained under the optimal extraction conditions of extraction time, 38min; ratio of water to material, 32mL/g; and extraction temperature, 56°C. These two values were agreed well with predicted yield (2.75%) and antioxidant capacity (18.77μmol Fe2+/g). Antioxidant activities of CPS were investigated by various assays. The results showed that CPSUAEobtained by UAE showed higher 1,1-Diphenyl-2-picrylhydrazxyl (DPPH), 2,2-azinobis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging activities and stronger reducing power, total antioxidant capacity compared with CPSHWEobtained by hot water extraction (HWE).The results indicated that UAE is an advisable method for extraction of antioxidant polysaccharides from the stem of T. quadrispinosa and polysaccharides could be explored as potential antioxidant to use in medicine or functional food.
authors.affiliation: School of Pharmacy, Jiangsu University, Zhenjiang, 212013, PR China.
authors.forename: Aun
authors.initials: A
authors.lastname: Raza
authors.affiliation: Affiliated Hospital of Jiangsu University, Zhenjiang, 212001, PR China; School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: School of Pharmacy, Jiangsu University, Zhenjiang, 212013, PR China. Electronic address: xxq781026@ujs.edu.cn.
authors.forename: Xiuquan
authors.initials: X
authors.lastname: Xu
authors.affiliation: School of Pharmacy, Jiangsu University, Zhenjiang, 212013, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Tang
mesh_terms: D001713:Biphenyl Compounds / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification*; D059625:Liquid-Liquid Extraction; D029561:Lythraceae / Q000737:chemistry*; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010851:Picrates / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification*; D013010:Sonication
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D011134:Polysaccharides; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Antioxidant polysaccharides; Response surface methodology; Trapa quadrispinosa Roxb.; Ultrasonic-assisted extraction