Milling and differential sieving to diversify flour functionality: A comparison between pulses and cereals.

Area of Science:

• Food Science and Technology
• Agricultural Science
• Material Science

Background:

• Seed processing techniques like milling and sieving create distinct flour streams (coarse, whole, fine).
• Understanding the techno-functional properties of these flour streams is crucial for optimizing food product development and ingredient functionality.

Purpose of the Study:

• To investigate the impact of particle size on the chemical composition and techno-functional properties of pulse (pea, lentil) and cereal (barley, oats) flours.
• To correlate particle size, chemical composition, and microscopic structure with specific functional attributes like viscosity, gel properties, and emulsification.

Main Methods:

• Milling of pulse and cereal seeds into whole flours, followed by sieving into coarse and fine fractions.
• Characterization of particle size distribution, starch content, damaged starch, ash, total dietary fiber, and protein content.
• Assessment of techno-functional properties including L* (brightness), gelatinization enthalpy (ΔH), gel hardness, foaming, emulsifying capacity, oil-binding capacity (OBC), and pasting viscosity.

Main Results:

• Particle size order was consistently coarse > whole > fine. Starch and damaged starch content increased from coarse to fine flours, while ash and total dietary fiber content showed the opposite trend.
• Functional properties related to starch (brightness, gelatinization enthalpy, gel hardness) followed the fine > whole > coarse order. Protein content varied by crop type, influencing foaming, emulsifying, and oil-binding properties.
• Pasting viscosity showed a clear fine > whole > coarse trend in pulse flours but not in cereal flours, attributed to differences in seed microstructure.

Conclusions:

• Particle size, chemical composition, and microscopic structure are key determinants of techno-functional properties in pulse and cereal flours.
• Tailoring flour particle size through milling and sieving allows for modulation of ingredient functionality for specific food applications.
• This research provides valuable insights for the food industry in selecting and processing pulse and cereal flours to achieve desired product characteristics.