Spinnability and rheological properties of globular soy protein solution

Spinnability and rheological properties of soy protein are studied for potential application in food products. It has been considered impossible to spin globular proteins due to the difficulty in extending the molecules to achieve high degree of intermolecular entanglement. In order to improve the spinnability of globular proteins, other polymers were incorporated. This paper shows a good spinnability of 100% globular soy protein. In this work, aqueous urea/reductant system is selected for efficient stretch and entanglement globular soy proteins for fiber spinning. In this system, hydrogen bonds, hydrophobic and electrostatic interaction were disrupted by urea, while disulfide bonds were cleaved by reductants. Moreover, the backbones of globular soy proteins were not severely destroyed, rendering the stretched globular protein spinnable and the spun fibers mechanically robust. Relationship between rheological properties and spinnability of globular soy protein solutions is quantified. In order to be spinnable, globular soy proteins should be highly stretched, and thus entangled with preserved backbones.