Evaluating the sterilization effect of wheat flour treated with continuous high-speed-stirring superheated steam

Abstract

In this study, the response surface methodology (RSM) was used to optimize the superheated steam sterilization conditions of wheat flour. Moreover; the impact of different treatment conditions on the physicochemical and structure of starch and protein in wheat flour was investigated. The three response variables (the total plate count, peak viscosity, and SDS sedimentation value) were determined to be most dependent on treatment time levels followed by moisture content and treatment temperature. Multiple-response optimization results showed that the treatment temperature 150 °C for 6 s at 13.5% moisture content was an optimal condition. In this case, the peak viscosity of wheat flour increased to 2560 cP, and enthalpy of gelatinization (ΔH) decreased to 5.67 J/g, while the crystalline structure and granular microstructure of starch were well maintained, and the ordering of protein was improved. Based on the optimized conditions, further increasing the treatment temperature, time, and moisture content, respectively, would destroy the physicochemical properties, among which the treatment time had the greatest effect.