Physico-chemical and functional properties of starch from stored potato: effect of anti-sprouting treatments

The freshly harvested potato tubers (Solanum tuberosum L.) of variety ‘Kufri Chipsona-4’ were cured for 18 days at 22 °C and 90% relative humidity. The cured potatoes were subjected to anti-sprouting treatments viz., hot water treatment [HWT] and Isopropyl N-(3-chlorophenyl) carbamate [CIPC] spray treatment. The treated potatoes were packed in nylon mesh bags and stored at 12 ± 1 °C temperature for a period of 120 days. The tuber samples were taken at a regular interval of 15 days for starch extraction and extracted starch was analyzed for physico-chemical and functional properties. It was observed that with the increase in storage period of potato tubers, there was a progressive decrease in the starch yield, purity, whiteness, amylose, syneresis, swelling power and solubility; while an increase was observed in the amylopectin, phosphorus content, water absorption capacity, light transmittance and peak viscosity of the extracted starch. On the 120th day of storage, the HWT (33.03%) and CIPC (28.09%) treatments had the lowest decrease in starch yield when compared to the control (44.23%). Throughout the storage period, the anti-sprouting treatments resulted in higher starch yield, phosphorus content, swelling power, solubility, water absorption capacity, light transmittance and peak viscosity of the extracted starch. The CIPC treatment was shown to be more effective than HWT and control at the end of the experiment due to higher starch yield (10.78%), swelling power (31.88%), solubility (27.23%), water absorption capacity (301.56%), light transmittance (39.33%), and low syneresis (27.40%).