Acid Beverage Floc from Sugar Beets

Abstract

Acid beverage floc (ABF), a flocculated turbid material that can form in sugar-sweetened, acidified, carbonated beverages after several days standing, is a customer problem to beverage bottlers and their suppliers of sugar. ABF from beet sugar has been reported to he caused by a saponin from the beet plant, and recent work has shown the presence of several saponins in sugarbeet. ABF from cane sugar is caused when a negatively charged cane polysaccharide forms a colloidal network with protein under acid conditions. Our investigations show that isolation and test procedures for saponins, as reported in the literature, are actually for oleanolic acid. ABF from beet sugar is proposed to have a two factor basis: a negatively charged component and a positively charged component interact at acid beverage pH, forming a coacervate and subsequently coagulating into a floc. The negatively charged factor can be oleanolic acid, any of the saponins that contain a glucuronic acid moiety, or beet cell wall polysaccharide containing uronic acids. The positively charged component can he protein or peptide, with isolectric point above the beverage pH of 2.5 to 3.0. ABF can he made by adding these components to non-floccing sugars.