Abstract

Abstract Highly concentrated biopolymers are used in food extrusion processing. It is well known that rheo-logical properties of biopolymers influence considerably both process conditions and product properties. Therefore, characterization of rheological properties under extrusion-relevant conditions is crucial to process and product design. Since conventional rheological methods are still lacking for this purpose, a novel approach is presented. A closed cavity rheometer known in the rubber industry was used to systematically characterize a highly concentrated soy protein, a very relevant protein in extruded meat analogues. Rheological properties were first determined and discussed in the linear viscoelastic range (SAOS). Rheo-logical analysis was then carried out in the non-linear viscoelastic range (LAOS), as high deformations in extrusion demand for measurements at process-relevant high strains. The protein showed gel behavior in the linear range, while liquid behavior was observed in the nonlinear range. An expected increase in elasticity through addition of methylcellulose was detected. The measurements in the non-linear range reveal significant changes of material behavior with increasing strain. As another tool for rheological characterization, a stress relaxation test was carried out which confirmed the increase of elastic behavior after methylcellulose addition.

Highlights

  • Highly concentrated biopolymers are used in food extrusion processing

  • Rheological properties play a crucial role in extrusion processing of highly concentrated biopolymers

  • Both viscous and elastic properties have an influence on the process conditions and product properties

Read more

Summary

Introduction

Abstract: Highly concentrated biopolymers are used in food extrusion processing. It is well known that rheological properties of biopolymers influence considerably both process conditions and product properties. Characterization of rheological properties under extrusionrelevant conditions is crucial to process and product design. Rheological properties were first determined and discussed in the linear viscoelastic range (SAOS). Rheological analysis was carried out in the non-linear viscoelastic range (LAOS), as high deformations in extrusion demand for measurements at process-relevant high strains. The measurements in the non-linear range reveal significant changes of material behavior with increasing strain. As another tool for rheological characterization, a stress relaxation test was carried out which confirmed the increase of elastic behavior after methylcellulose addition

Methods
Results
Conclusion

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.