Effect of Arabinoxylans, β-Glucans, and Dextrins on the Viscosity and Membrane Filterability of a Beer Model Solution

Abstract

High-molecular-weight substances in beer can cause filtration difficulties. The objectives of this research were to quantify the effects of arabinoxylan, β-glucan, and dextrin on the viscosity and membrane filterability of a beer model solution. Filterability was determined by using a modified Esser test, and viscosity was determined with a Brookfield rotational viscometer. It was found that addition of arabinoxylan, β-glucan, and dextrin increased viscosity of the model solution. Dextrin had the most pronounced effect on viscosity. The molecular weights of arabinoxylan and β-glucan were found to determine solution viscosity. Addition of arabinoxylan or β-glucan decreased filterability of the model solution, and arabinoxylan had the largest effect. Addition of dextrin did not decrease filterability. The molecular weights of arabinoxylan and β-glucan were found to be important to solution filterability but less important than was concentration. No significant interactions between the carbohydrates with respect to viscosity or filterability of the model solution were found. Viscosity was found to be a poor predictor of filterability across the range of carbohydrate concentrations evaluated in this study.