In this paper, influence of temperature (25, 35, 45 and 55 °C) and sugars (sucrose and lactose) at different concentrations (0, 5, 10 and 15%) on some molecular parameters of starches from two canary seed varieties (C05041 and CDC Maria) in the dilute regime were investigated in comparison to wheat starch (WS). The results indicated that the intrinsic viscosity ([η]) values of C05041, CDC Maria and WS samples were 1.42, 1.46 and 1.70 dl/g at 25 °C, respectively. Intrinsic viscosity of selected starches decreased with an increase in temperature, but the effect of high temperatures were somewhat unnoticeable. By increasing the sugar concentration, intrinsic viscosity of each starch solution significantly decreased in comparison with the value determined for sugar free solution. Lactose had more pronounced effect on the intrinsic viscosity reduction of CDC Maria starch and WS at 25 °C and 35 °C compared with sucrose (P < 0.05). But at 55 °C, the effect of increasing sucrose on decreasing of [η] of CDC Maria and WS samples were more considerable. The shape factor of starch samples at 25 °C were spherical, but increasing temperature from 25 °C to 55 °C, CSSs and WS samples took an ellipsoidal shape.

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