XRT for visualizing microstructure of extruded meat replacers

Area of Science:

• Food Science and Technology
• Materials Science
• Biophysics

Background:

• Extruded meat replacers often exhibit complex microstructures.
• Visualizing internal structures like lamella is crucial for understanding texture and properties.
• Traditional methods may lack the resolution or contrast for certain microstructural features.

Purpose of the Study:

• To evaluate X-Ray Tomography (XRT) as a method for visualizing the microstructure of high-moisture extruded meat replacers.
• To determine the effect of sample state (frozen vs. non-frozen) on XRT contrast and visualization of lamella.
• To compare lamella thickness in meat replacers with varying protein and fiber content.

Main Methods:

• High-moisture meat replacers were produced via extrusion.
• X-Ray Tomography (XRT) was employed to image the microstructure of both frozen and non-frozen samples.
• Image analysis was used to measure structural features, specifically lamella thickness.

Main Results:

• Lamella structures within the extrudates were visualized using XRT, particularly in frozen samples.
• Freezing significantly enhanced contrast in XRT by increasing density differences between water-rich and protein-rich layers.
• Non-frozen samples showed insufficient contrast for lamella visualization.
• Soy protein isolate (SPI) extrudates exhibited greater lamella thickness compared to more fiber-rich soy protein samples.

Conclusions:

• X-Ray Tomography (XRT) is a valuable technique for investigating the microstructure of extruded meat replacers.
• The freezing of samples is essential for achieving adequate contrast for XRT visualization of lamella.
• XRT can effectively quantify structural differences in extrudates resulting from compositional variations.