X-Ray microtomography imaging of red lentil puffed snacks: Processing conditions, microstructure and texture

Area of Science:

• Food Science and Technology
• Materials Science
• Biotechnology

Background:

• Red lentils offer superior nutritional value for puffed snacks but present textural challenges due to higher protein and fiber content compared to traditional ingredients.
• Optimizing the microstructure of red lentil extrudates is key to overcoming textural limitations and enhancing the quality of puffed snacks.
• Extrusion processing parameters offer a means to control the cellular structure and, consequently, the texture of puffed food products.

Purpose of the Study:

• To quantitatively characterize the microstructure of red lentil extrudates using X-ray microtomography.
• To investigate the relationship between extrusion processing parameters and the resulting extrudate microstructure and texture.
• To establish a foundation for optimizing extrusion parameters to achieve desirable textural qualities in red lentil puffed snacks.

Main Methods:

• Utilized X-ray microtomography to perform detailed microstructural characterization of red lentil extrudates.
• Analyzed the impact of extrusion parameters, including screw speed, moisture content, and blowing agent injection pressure, on microstructure.
• Quantified microstructural features such as cell size, cell wall thickness, and cell wall rupture.

Main Results:

• Increased blowing agent injection pressure correlated with smaller mean cell size, reduced wall thickness, and a higher cell count.
• Higher screw speeds induced visible cell wall rupture, an effect mitigated by increased moisture content.
• Significant reductions in extrudate hardness were associated with greater cell wall thickness variation, larger cell size, and increased wall rupture.

Conclusions:

• Extrusion processing parameters can be manipulated to control the microstructure of red lentil extrudates.
• X-ray microtomography provides valuable quantitative insights into the relationship between microstructure and texture.
• Achieving optimal texture in red lentil puffed snacks is feasible through precise control of extrusion parameters.