Effects of separation method of rice starch granules on their properties and structure

Rice starch granules were separated through three methods to investigate the effects of separation method on their properties and structure. The particle size distribution, microscopic morphology, hydration and pasting properties, gel texture, long-range and short-range ordering and thermal properties were compared.

The particle size of the separated starch granules by the three methods all fell within the typical range of rice starch granule size, which is between 1 and 20 μm. And the starch granules from colloid mill method (SG-CM) appeared smoother and more intact with a D₉₀ at 10.06 μm and D[4,3] at 6.01 μm. Furthermore, the gumminess of SG-CM gel was much higher than that of the other two gels, and remained unchanged compared with the rice flour gel before the separation of starch granules. The pasting properties of SG-CM were also closer to those of rice flour, accompanied by minimal deviation in relative crystallinity and hydration properties from rice flour.

Therefore, the colloid mill method has the least damage on the functional properties and structure of the separated starch granules, coupled with its green, safe and environmental friendly merits for the operational process and product. © 2026 Society of Chemical Industry.