The role of polysaccharides on the stability of colloidal particles of beer

Abstract

This study aimed at understanding the influence of beer colloidal composition and size on physical stability of the colloidal suspensions in beer before filtration. The percentages of retention during filtration indicate that colloidal particles consist principally of polysaccharides (97.04%) and smaller amounts of proteins (2.87%) and polyphenols (0.22). The viscosity of a colloidal dispersion can be modelled as the sum of a hard-sphere contribution and a colloidal force contribution. The colloidal force contribution is determined from the volume fraction of particles, the viscosity colloidal dispersion and the beer viscosity without particles. The volume fraction of particles could be estimated from the particle density and the total solid present in the beer. The fitting parameters of the correlation between the particles volume fraction and the colloidal force viscosity could explain the low stability of the colloidal particles of beer. This last determination is more specific than the simple viscosity of beer and could help to improve the prediction of the filtration flow.