Physico-chemical characterization of lesser known Palo (Curcuma leucorrhiza) starch

Palo (Curcuma leucorrhiza) starch is isolated from palo tuber, which is better known as hidden lilly and distributed in the hilly areas of Orissa, West Bengal, Jharkhand and Chhatishgarh. Its rhizomes are good source of starch. The starch extracted from the rhizomes has good application as herbal medicines, different foods and food ingredients such as palo laddu which is used specially during fasting as a part of ritual. It is believed that the consumption of palo starch powder removes the extra heat from the body and develops a resistance against the diseases. The proximate studies showed that the palo contains moisture 15.45% (db), ash 1.10%, fibre 1.23%, starch 81.33% and negligible fat. The scanning electron microscopy showed that curcuma starch consist of large oval to small spherical granules with a diameter ranged between 3050 μm. The surface of the granules appeared with evidence of certain fissure which might be due to rubbing action of occurred during starch isolation. X-ray diffraction studies of curcuma starch exhibited a B-type of crystal like other tuber starches and relative crystallinity was found to be 24.66%. Differential scanning calorimetric study showed that the curcuma starch had the gelatinization temperature of 59.5°C and enthalpy of gelatinization 5.565 J/g which might be due to the highest degree of crystallinity of its granules. The final viscosity of extracted starch observed higher than trough viscosity but lower than the peak viscosity which signifying the highest amylose retrogradation.