The investigation of heat-induced paramagnetic centers on rice pudding surface by electron spin resonance (ESR) technique

In this work thermally generated free radicals on rice pudding widely consumed in Turkey were investigated by ESR technique. The thermal behavior of the rice puding were invastigated by using Thermal Gravimetric Analysis (TGA) technique. The rice puding is widely consumed in Turkey. The rice pudding are used in this study were obtained from a local bakery in Izmir. The top portion of pudding material was used in the study. No signal was observed in unheated surface puding. However, a single-line ESR signal and spectroscopic splitting factor of the heated pudding surface was observed. ESR signals of free radicals generated by heating, changes depending on the heating temperature and heating time were examined. The relative number of paramagnetic species depends on the temprature and heating time. This increase indicates an increase in the density of the free radicals formed. We obtained that ESR signals curve depends on heating time. Based on this curve, we were examined that sold burning puding include how many free radicals and we examined density of free radicals from the changes depending on the heating temperature and heating time. According to TGA analysis, we obtain that weight loss at two different temperatures. The first of weight loss results from removal of water present in the rice pudding sample composition.The latter can be said be originated from plucked atom, molecules or molecular fragments from organic structure of rice pudding example.Taking the first derivative of the TGA curves, we was drawn of the Differential Thermal Gravimetric (DTG) curve.The temperature value which the weight loss occurred in the structure of rice pudding example at the TGA analysis is obtained approximately with the temperature value of thermally free radicals formed in ESR study.Namely, the TGA analysis for the rice pudding sample support the obtained results with the ESR method. The free radicals that is considered harmful to health depending on the heating temperature in the fried, roasted, burned or baked organic origin foodstuffs may occur, and ESR spectra can be observed.