# Physicochemical and Rheological Properties of Floury Rice Powder with Different Particle Sizes: Effects on Gluten-Free Sponge Cake Qualities

## TL;DR

This study examines how different particle sizes of rice powder affect the quality of gluten-free sponge cakes.

## Contribution

The study identifies optimal rice powder particle size for gluten-free cake quality based on physicochemical and rheological properties.

## Key findings

- Finer rice powder (80–100 mesh) improved cake specific volume and firmness.
- Smaller particle sizes increased solubility, pasting viscosity, and gel rigidity.
- FR3 and FR4 cakes showed better morphological structure compared to coarser fractions.

## Abstract

This study investigated the physicochemical and rheological properties of floury rice powder (FRP) with different particle sizes and their effects on the quality characteristics of gluten-free butter sponge cake. Soft rice grain (Baromi2 variety) was dry-milled and sieved into four fractions: FR1 (60 mesh overs), FR2 (60–80 mesh), FR3 (80–100 mesh), and FR4 (100 mesh throughs). FRP fractions were analyzed for chemical composition, swelling power, solubility, gelatinization, pasting viscosity, and viscoelastic property. Gluten-free cakes made using a whole-egg foam method were evaluated for morphological structure, baking loss, moisture, specific volume and firmness. With decreasing FRP particle size, there were increasing trends in solubility, pasting viscosity, resistance to deformation, viscoelastic attributes (G′ and G″), and gel rigidity. FR3 and FR4 cakes exhibited flat and puffy loaves compared to FR1 and FR2 cakes with loaf collapses. The finer FRP enhanced the morphological balances of the cakes. Increasing trends in specific volume and firmness were observed as FRP particle size decreased. These results paralleled the solubility, pasting, rheological, and gelling properties of FRP itself. Overall, the results suggest that the rheological and gelling properties of FRP may play a role in determining the quality of gluten-free sponge cakes. In addition, FRP with a particle size of 80–100 mesh appears most appropriate for gluten-free sponge cake.