Turmeric Powder and Starch: Selected Physical, Physicochemical, and Microstructural Properties.

Turmeric powder and its starch were characterized for physical, physicochemical, and microstructural characteristics.
X-ray diffractogram indicated that turmeric starch to be of B type. Dried and cured-dried turmeric powder
samples showed higher water-holding capacity (3.62 and 4.78 g/g, respectively) compared to isolated starch (1.07 g/g)
at 30 ◦C. Non-Newtonian shear-thinning characteristics were observed with turmeric powder dispersion containing
10% (w/w) solids. A power law model fitted well to correlate the shear-rate and shear-stress data (r = 0.993 to 0.999,
P ≤ 0.01) for both samples. Apparent viscosities of isolated turmeric starch and cured-dried turmeric powder dispersion
containing 10% (w/w) solids were 1.29 ± 0.03 and 7.57 ± 0.39 mPa s, respectively. Microstructure of starch particles
showed a smooth flat outer surface. The approximate length and breadth of isolated elliptical starches were 25 and 10 μm
while the thickness was about 5 μm.