Small and large oscillatory shear properties of concentrated proteins

Thermo-mechanical processing of plant proteins using shear cell and high-moisture extrusion cooking

“…Furthermore, preventing moisture losses is challenging when temperatures exceed 100 C. Several manufacturers of bench-top rheometers do offer pressure cells for use with existing bench-top rheometers. The ability to perform rotational experiments and the greater torque sensitivity could prove advantageous as the viscosity of the protein melt is rather low (Schreuders et al 2021).…”

“…The use of large amplitude oscillatory shear (LAOS) rheology as well as the energy dissipation ratio, which shows a simplified perspective to reveal the complex information in the Lissajous curve, have also been picked up as tools to study melt properties (Schreuders et al 2021). LAOS provides information on the rheological properties beyond the linear viscoelastic regime but is more difficult to interpret than conventional small amplitude oscillatory shear (SAOS) measurements (Hyun et al 2011).…”

“…LAOS provides information on the rheological properties beyond the linear viscoelastic regime but is more difficult to interpret than conventional small amplitude oscillatory shear (SAOS) measurements (Hyun et al 2011). Using LAOS methods it was found that a thermal treatment can increase the elasticity of protein networks (Schreuders et al 2021). The thermal treatment caused pea protein isolate to lose its elastic properties more quickly than soy protein isolate and gluten.…”

Methods for Testing the Quality Attributes of Plant-Based Foods: Meat- and Processed-Meat Analogs

“…To understand the behavior in the nonlinear region, large amplitude oscillatory shear (LAOS) experiments are used to ascertain the behavior of the material under high strains that mimic those real products may experience, e.g., shearing, extruding, cutting, or chewing [ 85 ]. The sample is sheared in oscillatory mode using a constant frequency (often 1 Hz) at increasing strain, commonly from 0.1 to 1000% [ 85 , 86 ]. The material response in LAOS experiments is not analyzed by evaluating the behavior of stress and strain over time (as in SAOS experiments), but the stress is plotted against the strain or strain rate, which yields so-called Lissajous plots.…”

“…The material response in LAOS experiments is not analyzed by evaluating the behavior of stress and strain over time (as in SAOS experiments), but the stress is plotted against the strain or strain rate, which yields so-called Lissajous plots. Detailed examples and interpretations of such plots can be found in Schreuders [ 86 ]. In general, the plots give insights into the viscous and elastic behavior of the material at different strains, which is helpful to understand the material characteristics for extrusion and shearing processes.…”