Effect of Temperature, Solvent Concentration, and pH on the β-Glucan Extraction

Abstract This study investigated the effects of temperature, solvent concentration, and pH on the β-glucan extraction. Oat bran β-glucan was extracted with different extraction conditions, using various combinations of experiment factors, such as temperature (40, 45, 50, 55, and 60℃), ethanol concentration (0, 5, 10, 15, and 20%), and pH (5, 6, 7, 8, and 9). Under the various extraction conditions, β-glucan extraction rate and overall mass transfer coefficient of oat bran β-glucan, and viscosity of oat bran extracts were investigated. As increasing the extraction time, the extraction rate of β-glucan increased. The overall mass transfer coefficient of β-glucan ranged from 3.36×10 －6 to 8.55×10 －6 ㎝/min, indicating the lowest at the extraction condition of 45℃, 15% and pH 8, and the highest at 50℃, 0% and pH 7. It was significantly greater with increasing extraction temperature and decreasing ethanol concentrations of extraction solvent, except for solvent pH. There were positive correlations among the overall mass transfer coefficient, the extraction rate of β-glucan, and the viscosity of extract. Key words: oat bran β-glucan, extraction conditions, extraction rate, viscosity, overall mass transfer coefficient