Barley β-glucans extraction and partial characterization

Abstract

Barley is rarely used in the food industry, even though it is a main source of β-glucans, which have important health benefits and a technological role in food. This work evaluated the humid extraction of barley β-glucans and partially characterized them. The extraction was studied using surface response methodology with both temperature and pH as variables. The extracted β-glucans were characterized by chemical and rheological analysis, infrared spectroscopy and scanning electron microscopy. The effect on extraction of linear and quadratic terms of pH and temperature corresponding to the regression model was significant, and we obtained a maximum concentration of 53.4% at pH 7.56 and temperature 45.5°C, with protein and mainly starch contamination. The extracted β-glucans presented a higher apparent viscosity than the commercial ones, the behavior of the commercial and extracted samples can be described as Newtonian and pseudoplastic, respectively. The results of infrared spectroscopy and scanning electron microscopy were characteristic of commercial β-glucans, indicating that this method is efficient for extracting β-glucans.

Keywords: Barley; Characterization; Extraction; Rheology; Viscosity; β-glucans.