Physicochemical properties of pre-gelatinized wheat starch produced by a twin drum drier.

Wheat starch is the most common type of starch in Iran as well as many other parts of the world with enormous applications in food and non-food products. To improve its physicochemical properties or create new functionalities, starch can be modified by changing its molecular structure. Amongst different methods for starch modification, physical methods have received more attention recently. Pre-gelatinization of starch is a physical method to modify the properties of native starch. The main aim of this research was to study the physicochemical properties of pre-gelatinized wheat starch produced using a small scale industrial twin drum drier. The results indicated that drum drying destroyed native starch granules, degraded molecular structure and reduced the degree of crystallinity of starch. Pre-gelatinized starch (PGS) showed cold water viscosity at 25 oC, while native wheat starch was not able to increase the viscosity under this condition. It also increased water absorption and swelling of the starch compared to its native counterpart. Pre-gelatinized wheat starch can be used as a thickening agent in instant food products to eliminate heating stage in their production or in manufacturing of the products sensitive to high temperature.