Dynamic rheological properties of rice flour-starch blends

The dynamic rheological properties of blends of rice flour (RF) with six different commercial starches (sweet potato starch, potato starch, tapioca starch, waxy corn starch, hydroxypropylated potato starch, and hydroxypropylated tapioca starch) were evaluated. The magnitudes of storage modulus (G′) of all blend samples were higher than those of loss modulus (G′) over most of the frequency range (0.63-62.8 rad · s^-1). In general, the dynamic moduli results of all blend samples showed that changes in G′ values were relatively greater than changes in G′ values after adding the starches when compared to RF. tan δ (ratio of G′/G′) values (0.21-0.22) of the RF-potato starch and RF-hydroxypropylated potato starch blends were much lower than those (0.25-0.33) of other blends and RF, indicating that there is a more pronounced synergistic effect on the elastic properties of RF-starch blend systems in the presence of potato starches.