Nuclear chemistry

Hydroxyl radical

Polymerization

Engineering

Chromatography

Glucomannan

Hydrolysate

Chemical engineering

Food science

Polymer

Organic chemistry

Scavenging

Antioxidant

Hydrolysis

Chemistry

Enzymatic hydrolysis

Fourier transform infrared spectroscopy

Degree of polymerization

DPPH

Carbohydrate Polymers

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 2 h; 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.

Preparation, composition analysis and antioxidant activities of konjac oligo-glucomannan