Study on Configuration Design and Numerical Simulation of Twin-Screw Extruder Cooling Die Based on Pea Protein...

Area of Science:

• Food Science and Technology
• Materials Science
• Chemical Engineering

Background:

• Plant-based meat alternatives require improved texture and fibrous structure for consumer acceptance.
• Protein extrusion is a key process for creating meat-like textures, but controlling structure remains challenging.

Purpose of the Study:

• To develop and evaluate optimized cooling die configurations for improved fibrous structure in protein extrudates.
• To investigate the impact of die geometry and cooling channel design on pea protein isolate (PPI) extrusion.

Main Methods:

• Numerical simulations were employed to analyze six cooling die designs with varying cross-sectional shapes and flow channel layouts.
• The physical properties of pea protein isolate (PPI), including its shear-thinning behavior and viscosity changes with temperature, were characterized.
• Key performance indicators such as temperature difference, heat transfer coefficient, viscosity ratio, and shear rate were evaluated.

Main Results:

• Pea protein isolate (PPI) demonstrated significant shear-thinning behavior, with viscosity dropping over 85% as temperature increased from 35°C to 135°C.
• The rectangular outlet combined with a serpentine cooling channel yielded the best performance, achieving a 12.4°C center-to-wall temperature difference and a 35% higher heat transfer coefficient.
• This optimal design resulted in a higher wall-to-center viscosity ratio (7.4) and maximum wall shear rate (3.42 s⁻¹), promoting better fiber alignment.

Conclusions:

• The optimized rectangular die with a serpentine channel effectively enhances the center-to-wall temperature and shear gradients, crucial for improved fiber formation.
• This configuration offers a practical and theoretically grounded method for controlling fiber alignment and texture in plant-based meat production.
• The findings provide valuable insights for designing advanced extrusion dies to meet the growing demand for high-quality plant-based meat alternatives.