Dynamic rheological and morphological properties of Phosphorylated, hydropropylated and dual modificated wheat starch

In this study, dynamic rheological properties of wheat starch gels as a function of starch chemical modification (Phosphorylation, hydroxypropylation and dual modification) were studied. The hydroxypropyl- phosphorylated and hydroxypropylated wheat starch gels had higher dynamic modulus (storage modulus (G ) and loss modulus (G )) compared to the native and Phosphorylatedwheat starches. All of treatments showed higher elastic modulus than those for control that led to lower tangent values than 1. Unlike the native and phosphorylated wheat starches samples which exhibited an intermediate behavior between a weak and an elastic gel, the hydroxypropylated and hydroxypropyl- phosphorylated samples relatively showed an elastic gel behavior. The results of creep-recovery test illustrated that the stronger starch gel samples, which had greater resistance to deformation had smaller, creep compliance values. The results explained that the hydroxypropylated and hydroxypropyl- phosphorylated wheat starches had specific dynamic rheological properties which make it different for applied in different gel-like foods.

کلیدواژه ها:

Wheat starch ، hydroxypropylation ، phosphorylation ، dynamic rheological properties ، Creep- recovery test