Turbo-Treatment of Rice Flour to Improve Technological Functionality

Turbo-technology (i.e., a heat/shear treatment) potential in modifying rice flour technological properties (i.e., damaged starch, pasting properties, apparent cold viscosities, and color) depending on cooking temperature (120-200 degrees C), added water (30-40%), and drying temperature (160-200 degrees C) was evaluated. Applying a Box-Behnken design, highly significant (p < 0.001) models were found for moisture, damaged starch, pasting properties, and cold viscosities. The most important factor was the added water, significantly (p < 0.001) affecting all treated flour characteristics. The optimization resulted in 200 degrees C as cooking and drying temperature and 40% added water, but values of damaged starch and cold viscosities in the treated flour were still low. Thus, flour was overnight wetted (40% water) before cooking and drying at 200 degrees C, obtaining high values of damaged starch (49.5 +/- 1.5 g/100 g db) and cold viscosities (from 6213 to 21,436 cP). The study represents a guide for the application of turbo-technology to design flour with tailored technological properties.