Pre-gelatinisation of native potato starch by thermal treatment in a pilot-scale superheated steam spray drying system

Abstract

Superheated steam spray drying has the potential to significantly reduce the net energy consumption of drying processes. Food products have been successfully dried in laboratory scale systems with unique characteristics.

Thermal modification of starch for food applications by superheated steam spray drying is therefore an energy efficient alternative to existing processes. A native potato starch was used to demonstrate the applicability and evaluate the properties of the resulting cold swelling and cold dissolving pregelatinised potato starch. The thermal effects of atomisation and drying under superheated steam atmosphere were evaluated using a closed-loop superheated steam spray drier at pilot plant scale with inlet temperatures between 170 °C and 230 °C. The resulting cold-swelling potato starch granules are intact and the gel has an initial viscosity that is twice that of the drum-dried reference material at the same concentration. The viscosity of the resulting gel is boiling-stable offering opportunities for instant products that can be served at elevated temperatures for consumption.