Starch radicals. Part II: Cereals - native starch complexes

Several varieties of flours were subjected to thermolysis up to 400 degrees C. The thermal characteristics of 13 flours were similar for ali flours except soy. The weight loss of these flours up to 400 degrees C ranged from 65 to 97%. Although flours began to decompose at lower temperatures than did corresponding starches, there was less radical decomposition in flours than in starches as proved by Electron Paramagnetic Resonance absorption (EPR) spectra. The order of heat resistance to the radical decomposition for starches and flours paralleled one another, however, flours generated radicals at temperatures approximately 20 degrees C higher than in corresponding starches. The data showed that cereals did not form free radicals before carbonization and thus they could be safely processed in the temperature intervals generally used in baking, roasting, and frying. (C) 1998 Elsevier Science Ltd. All rights reserved.