Physicochemical and Rheological Properties of Floury Rice Powder with Different Particle Sizes: Effects on...

Area of Science:

• Food Science
• Materials Science
• Rheology

Background:

• Gluten-free baking presents challenges in achieving desirable texture and structure.
• Floury rice powder (FRP) is a potential gluten-free flour, but its properties require optimization.
• Particle size is a critical factor influencing the physicochemical and rheological behavior of powders.

Purpose of the Study:

• To investigate the impact of different floury rice powder (FRP) particle sizes on its physicochemical and rheological properties.
• To evaluate how these properties influence the quality characteristics of gluten-free butter sponge cakes.
• To determine the optimal FRP particle size for gluten-free sponge cake production.

Main Methods:

• Soft rice grain was dry-milled and sieved into four particle size fractions (FR1-FR4).
• Physicochemical analyses included swelling power, solubility, gelatinization, and pasting viscosity.
• Rheological properties (viscoelasticity) and cake quality (morphology, volume, firmness) were assessed.
• Gluten-free cakes were prepared using a whole-egg foam method.

Main Results:

• Decreasing FRP particle size increased solubility, pasting viscosity, and viscoelastic properties (G', G″).
• Finer FRP (FR3, FR4) improved cake morphological balance, resulting in flatter, puffier loaves compared to coarser fractions (FR1, FR2) which caused loaf collapse.
• Increased specific volume and firmness were observed with smaller FRP particle sizes, correlating with improved solubility, pasting, and rheological properties.

Conclusions:

• The rheological and gelling properties of FRP are crucial for gluten-free sponge cake quality.
• FRP with a particle size range of 80-100 mesh is optimal for producing high-quality gluten-free sponge cakes.
• Particle size engineering of FRP offers a viable strategy to enhance gluten-free baked goods.