Optimising separation process of protein and polysaccharide from spent brewer's yeast by ultrafiltration

The aim of this study was to optimise the ultrafiltration process for the separation of polysaccharide and protein from spent brewers yeast. Influence of concentration (1.54.5%), pH (4.08.0) and operating pressure (1020 psi) on the yield of protein and polysaccharide was assessed using response surface methodology. The optimum separation conditions were found to be concentration 2.7%, pH 5.0 and operation pressure 14.0 psi. Under these conditions, the experimental yields of protein and polysaccharide were 95.03% and 94.65%, respectively, which were agreed closely to the predicted value. The polysaccharide was composed of glucose, sucrose and trehalose in a ratio of 1.12:0.83:2.36. The results indicated that ultrafiltration technology could be an effective and advisable technique for the separation of protein and polysaccharide.