The clarification of mechanically disrupted yeast suspensions by rotary vacuum precoat riltration

Abstract

AbstractRotary vacuum precoat filtration of bakers' yeast disrupted in a high‐pressure homogenizer is reported. Different precoat materials, knife cutting rates, and body feeds were tested on disrupted yeast suspensions ranging from 10 to 40% wt packed yeast/vol. The flow rates, solids contents, and protein and enzyme concentrations before and after filtration were determined. Filtration rates were found to be independent of precoat thickness during debris filtration. For 20% disrupted yeast, flow rates of up to 17 cm3/cm2/hr were attained at a precoat and body feed usage of 35 kg/1000 liters. By reducing the knife cutting speed to 0.025 mm/min and the body feed to 1% the filter aid usage could be reduced to 13.5 kg/1000 liters while maintaining a flow rate of 9.3 cm3/cm2/hr. In all experiments protein recoveries were in the range of 80−90% and with the four enzymes examined, recoveries ranged from 67−92%. With all the precoats tested, the product had a lower solids content than that obtained from centrifuges capable of processing similar quantities of cell debris.