Rheological study of starch extracted from germinated and non-germinated maize vis-a-vis printing

Due to the untimely rains and inadequate storage facility, a lot of wheat, maize, jowar, rice, etc. often get dampened and start germinating becoming unacceptable for edible consumption. In the current study the starches are extracted from germinated as well as non-germinated maize grains by alkali steeping method and their employability as printing thickener is studied. The study of rheology of these starches and their blends is also carried out. The effect of solid content and the shearing time on the viscosity of the paste has been studied and the shear thinning index (STI) and the values of viscosity at 1 rpm shear rate (i.e. K value) are used to compare the behaviour of both the starches. The effect of rheological behaviour of starch paste on the printing properties is confirmed in printing of vat dyes on cotton, using these starches as thickener paste.