Rheological, functional and thermal properties of the blend system of canary seed starch-wheat starch gels

摘要

In this paper, some functional, thermal, textural, and rheological properties of the blends of two canary seed starches (CDC Maria and C05041 varieties) and wheat starch (WS) were studied to assess their suitability as an alternative for chemically modified starches. The blends of CDC Maria starch (CSS1-WS) and C05041 starch (CSS2-WS) were prepared in the ratio of 25:75, 50:50, and 75:25. The blend with the highest proportion of CSS2 (CSS2-75) represented the highest water and oil absorption capacity, more temperature dependency, lesser syneresis, and thus the highest freeze-thaw stability. The results of rheological properties revealed that the Power-law, Casson, and first-order stress decay models were the best ones for describing the time-independent and time-dependent behaviors of the selected starches, and their blends, respectively. The gained output from the Power-law model displayed that the pseudoplasticity of all starch gels reduced by increasing the CSS portions into the mixture. Increasing the ratio of CSSs in the mixture from 25 to 75% caused an appreciable increase in both yield stress (12.52-20.13%) and plastic viscosity (16.47-33.73%) values. The extent of thixotropy for the CSS1-WS blend decreased by increasing the portion of CSS1 in the mixture, opposite of the effect of raising the portion of CSS2 in the mixture.