RHEOLOGICAL PROPERTIES AND SPINNABILITY OF SINGLE‐CELL PROTEIN/ADDITIVE MIXTURES

Abstract

ABSTRACTThe rheological properties of single‐cell protein (SCP) extracted from Torula dried yeast, under a wide range of shear, and the potential for forming a continuous and uniform filament were studied. Additions of various reagents to the extracted SCP were made to investigate their effects on flow behavior and spinnability. A cone‐and‐plate viscometer was applied to obtain rheological measurements. At higher shear rates, a capillary rheometer was used and the spinnability of these SCP/additive mixtures was observed simultaneously. Among the alkali‐modified samples, pH 9 dope containing 20% SCP showed best spinnability with a moderately high apparent viscosity. When the reagents which induce intermolecular linkage were incorporated, the apparent viscosity of the alkali SCP dope changed and also the spinnability. Formaldehyde appeared to affect the dope's behavior most drastically. The formalde‐hyde/SCP dope formed a gel‐like structure at ambient temperature and rendered the highest apparent viscosity, but was poor in filament forming capability. With the addition of carboxymethyl cellulose or carrageenan, spinnability improved accompanied with a slight increase in the apparent viscosity of the SCP dope.