Preparation of spent brewers yeast (beta)-glucans for potential applications in the food industry

A preparation of (beta)-glucan, obtained from spent brewerʹs yeast, was evaluated for potential food applications. This material was autolysed and the cell walls that were obtained were homogenized, extracted firstly with alkali, then with acid, and then spray dried. Effects of the homogenization on the chemical composition, rheological properties and functional properties of (beta)-glucan were investigated. Homogenized cell walls exhibited higher (beta)-glucan content and apparent viscosity than those which had not been homogenized because of fragmentation of the cell walls. When compared with commercial (beta)-glucan from bakerʹs yeast, it was found that the (beta) -glucan obtained from this study had higher apparent viscosity, water-holding capacity and emulsion stabilizing capacity, but very similar oil-binding capacity. These findings suggest that (beta)-glucan obtained from brewerʹs yeast can be used in food products as a thickening, water-holding, or oil-binding agent and emulsifying stabilizer.