Turmeric powder and starch: selected physical, physicochemical, and microstructural properties

Area of Science:

• Food Science
• Materials Science
• Biochemistry

Background:

• Turmeric (Curcuma longa) is a widely used spice with potential for novel ingredient development.
• Starch characterization is crucial for understanding its functional properties and applications.
• Exploring unconventional sources for starch isolation can lead to new functional ingredients.

Purpose of the Study:

• To characterize the physical, physicochemical, and microstructural properties of turmeric starch.
• To evaluate the potential of turmeric starch as a functional ingredient.

Main Methods:

• X-ray diffractogram for crystalline structure analysis.
• Water-holding capacity measurements at 30 °C.
• Rheological measurements (shear rate vs. shear stress) using a power law model.
• Microstructural analysis of starch particles.

Main Results:

• Turmeric starch is of B-type crystalline structure.
• Dried and cured-dried turmeric powder showed higher water-holding capacity than isolated starch.
• Turmeric powder dispersion exhibited non-Newtonian shear-thinning behavior, well-fitted by a power law model.
• Apparent viscosity of isolated starch and cured-dried turmeric powder dispersion were determined.
• Starch particles were elliptical with smooth, flat outer surfaces (approx. 25x10x5 μm).

Conclusions:

• Isolation and characterization of turmeric starch reveal its potential as a functional ingredient.
• Turmeric starch can be utilized in the food and pharmaceutical industries, particularly for agglomerated products.