Rheological Properties
Rheological properties of samples were investigated according to a
previous study [20]. Samples were prepared in 10 mg
mL-1 deionized water at 95 ºC for 20 min, and kept
mixing for 60 min to ensure complete solubilization, then equilibrated
30 min at ambient temperature. After processing, the sample was laid in
an aluminum parallel plate and analyzed by a Discovery HR-2 rheometer
(TA Instruments Ltd., New Castle, DE). The experimental conditions were
as following: 40 mm diameter, 1 mm gap and 25 ºC temperature. The strain
sweeping from 0.1 to 10% was performed at 1 Hz frequency. The frequency
sweeps with a fixed strain of 1% were measured by the range from 100 to
0.01 rad s-1 at room temperature within the linear
viscoelastic range. The storage modulus (G′) and loss modulus (G′′) were
automatically recorded. Data were collected according to the logarithmic
mode and performed in triplicate.