Siddiqui, SaleemNeeraj2017-09-292017-09-292017http://krishikosh.egranth.ac.in/handle/1/5810031951The present study was carried to find out the physiochemical and functional properties of starch isolated from potatoes by various extraction methods, from different varieties and after subjecting the tubers to various postharvest and storage conditions. The fresh potato tubers of variety Kufri Bahar were used for extraction of starch by various extraction methods viz., T1= Control (Ambient Water-30°C), T2 = Cold Water-10°C, T3 = Hot Water- 60°C, T4 = NaOH-0.1%, T5 = NaOH-0.25%, T6 = SDS-ME-1%, T7 = SDS-ME-2%, T8 = Propanol-water (3:1 w/v), T9 = Na-bisulphite-0.1%, T10 = Na-bisulphite-1.7%, T11 = Na-hypochlorite (5.25%), T12 = Protease (0.01%), T13 = Cellulase (0.15%) and T14 = Combined treatment (T5 + T7 + T11 + T13). The starch extracted by various methods was analysed for different physiochemical and functional characteristics and T14 (Combined treatment) was found to be the best method, showing significantly higher starch yield, WAC, starch purity, swelling power, solubility, light transmittance, whiteness, trough viscosity and final viscosity; and lower amylose, phosphorus, moisture, protein, fat, ash, crude fiber, syneresis, peak viscosity, breakdown viscosity and setback viscosity than control. The combined method was used for extraction of starch from the fresh as well as cured potatoes of white flesh varieties (Kufri Chipsona-4, Kufri Badshah, Kufri Pushkar, Kufri Bahar) and pink flesh variety (Kufri Sindhuri). The starch extracted from these varieties was also analysed for starch yield, various physiochemical and functional characteristics. Among the various varieties of potato, Kufri Chipsona-4 showed higher starch yield, water absorption capacity, swelling power, solubility, light transmittance and peak viscosity. For all the varieties, curing resulted in lower starch yield, amylose content, swelling power, solubility and starch whiteness value; higher amylopectin, phosphorus content, WAC, light transmittance and peak viscosity; and non-significant changes in starch moisture, protein, fat, crude fiber, ash content and purity. The cured tubers of variety Kufri Chipsona-4 were subjected to sprout inhibiting treatments viz., hot water dip treatment (57.5±0.1oC for 20 min) and isopropyl N-(3 chlorophenyl) carbamate (CIPC) treatment. The treated potato tubers were packed either in nylon mesh bags or MAP or vacuum packaging and stored either at room temperature (RT) (32±2oC; RH ~90%) or low temperature (LT) (12±1oC) conditions. It was observed that there was a progressive increase in sprouting, PLW, decay loss and shriveling of potato tubers during storage, magnitude being higher at room temperature (RT) than low temperature (LT) conditions. With increasing storage period of tubers, both at RT and LT conditions, the extracted starch’s moisture content, fat, ash, crude fiber, amylopectin, phosphorus content, water absorption capacity, light transmittance and peak viscosity of stored potatoes increased; while yield, purity, amylose, swelling power, solubility, syneresis and colour whiteness value decreased. At LT storage conditions, CIPC was more effective sprout inhibiting treatment than HWT. The effect of various sprout inhibiting treatments was found to be nonsignificant on starch’s moisture content, protein content, fat content, crude fiber, ash content, purity, WAC and colour whiteness values; while higher yield, amylopectin, phosphorus content, swelling power, solubility, light transmittance and peak viscosity were observed in starch extracted from CIPC than hot water treated tubers stored at LT. The various packaging methods did not significantly affect the moisture, fat, protein, ash, crude fiber, purity, amylose, amylopectin, WAC, swelling power and starch whiteness values of the starch extracted from tubers stored at LT.ennullThesis