Physicochemical, thermal and pasting properties of starches separated from different potato cultivars grown at different locations

Abstract

The starch separated from 21 different Indian potato cultivars from four locations was evaluated for physicochemical, thermal and pasting properties. The relationships between the different properties of starches were determined using Pearson’s correlation analysis. Amylose content was positively correlated to hot paste viscosity ( r = 0.460, P ⩽ 0.05) and negatively correlated to transmittance measured after storage of 0, 24 and 72 h ( r = −0.509, −0.480, −0.453, P ⩽ 0.05). Hot paste viscosity showed significant positive correlation with cold paste viscosity, pasting temperature, T p and T c ( r = 0.985, 0.607, 0.654, 0.628, P ⩽ 0.005) and negative correlation with transmittance measured after 0, 24 and 72 h ( r = −0.539, −0.570, −0.451, P ⩽ 0.05). Breakdown viscosity showed highly negative correlation with pasting time ( r = −0.766, P ⩽ 0.005) and positive correlation with transmittance measured after 0, 24 and 72 h ( r = 0.533, 0.558, 0.570, P ⩽ 0.05). Pasting temperature showed highly positive correlation with transition temperatures T o, T p, T c ( r = 0.740, 0.846, 0.734, P ⩽ 0.005) and negative correlation with transmittance measured after 0, 24 and 72 h ( r = −0.418, −0.468, −0.476, P ⩽ 0.05). T o showed the highest positive correlation with T p and T c ( r = 0.924, 0.755, P ⩽ 0.005). The results revealed that temperature during tuber growth affects granule size, pasting temperature and transition temperature. Lower temperature prevailed during tubers growth resulted into starch with higher granule size and lower pasting and transition temperatures.