Rheological properties, water-holding and oil-binding capacities of particulate β-glucans isolated from spent brewer's yeast by three different procedures

Particulate β-glucans were isolated from brewer's yeast using three different procedures--alkaline (A), alkaline-acidic (AA) and alkaline-acidic with mannoprotein removal (AAM) and dried using three different methods--air drying (AD), lyophilization (L) and spray drying (SD). In this work, the obtained β-glucan preparations were tested for their microstructure, rheological properties, swelling, water-holding and oil-binding capacities. According to their rheological properties, suspensions containing 1 and 2% (by mass) of spray-dried samples belong to the category of dilatant fluids. Among the spray-dried samples, rheological behaviour and water-holding capacity of the preparation AA-SD differed from those obtained by other two procedures (A-SD and AAM-SD). Concerning different drying methods applied, swelling was the lowest in the lyophilized samples and the most pronounced in the air-dried ones. Oil-binding capacity was the highest in the lyophilized preparations and increased proportionally to the number of processing steps applied in the isolation procedure. Key words: brewer's yeast, oil-binding capacity, particulate β-glucan, rheology, swelling, water-holding capacity