title: Preparation, composition analysis and antioxidant activities of konjac oligo-glucomannan.
abstract: Konjac oligo-glucomannan (KOG) was prepared by degradation of konjac glucomannan (KG) using β-mannanase. The hydrolysis process was monitored by the viscosity of the enzymatic hydrolysates. Factors affecting the enzymatic hydrolysis of KG were investigated, and the optimum hydrolysis conditions were as follows: time 2h; temperature 50°C; pH 6.0; and enzymatic concentration 150 U/g. Under these optimized conditions, minimum viscosity (31.9 mPa·s) of the hydrolasate was obtained. The average degree of polymerization (DP) of the resulting KOG was approximately equal to 5.2. The results of Fourier transform infrared (FTIR) spectra of KG and KOG indicated that KG was successfully degraded. In addition, their antioxidant activities were evaluated by determination of hydroxyl radical (•OH) and 1,1-diphenyl-2-picrylhrazyl radical (•DPPH) scavenging activity, and determination of reducing power. The results showed that KOG exhibited significant antioxidant activities. Taken together, this study suggested that KOG could potentially be used as a natural antioxidant.
authors.affiliation: Department of Food Science and Engineering, College of Ocean, Zhejiang University of Technology, Hangzhou 310014, PR China. Electronic address: jhliu@zjut.edu.cn.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Food Science and Engineering, College of Ocean, Zhejiang University of Technology, Hangzhou 310014, PR China.
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Department of Food Science and Engineering, College of Ocean, Zhejiang University of Technology, Hangzhou 310014, PR China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Food Science and Engineering, College of Ocean, Zhejiang University of Technology, Hangzhou 310014, PR China.
authors.forename: Xuxia
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Food Science and Engineering, College of Ocean, Zhejiang University of Technology, Hangzhou 310014, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Lyu
authors.affiliation: Department of Food Science and Engineering, College of Ocean, Zhejiang University of Technology, Hangzhou 310014, PR China. Electronic address: zhpch@zjut.edu.cn.
authors.forename: Peicheng
authors.initials: P
authors.lastname: Zhao
authors.affiliation: Department of Food Science and Engineering, College of Ocean, Zhejiang University of Technology, Hangzhou 310014, PR China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Ding
mesh_terms: D031056:Amorphophallus / Q000737:chemistry*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000737:chemistry; D006868:Hydrolysis; D017665:Hydroxyl Radical / Q000737:chemistry; D008351:Mannans / Q000737:chemistry* / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010851:Picrates / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D044902:beta-Mannosidase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D008351:Mannans; D010851:Picrates; D017665:Hydroxyl Radical; C022901:(1-6)-alpha-glucomannan; C004931:1,1-diphenyl-2-picrylhydrazyl; D044902:beta-Mannosidase
keywords: Antioxidant activity; Composition; Konjac glucomannan (KG); Konjac oligo-glucomannan (KOG); β-Mannanase