Quality Evaluation and Physical Identification of Irradiated Dried Fruits

Abstract

Raisins (Thailand), dried mangos (Philippines), and dried figs (Iran) were gamma-irradiated (0～5 kGy), and their quality and detection characteristics were investigated. Microbiological characteristics were at safe levels when samples were irradiated at higher than 3 kGy. In color change after irradiation, dried mangoes were the most sensitive. Photostimulated luminescence (PSL) measurement was not applicable to dried fruits, showing negative or intermediate values for the irradiated samples. Thermoluminescence (TL) measurement was good for dried figs, exhibiting a glow curve in range of 150～200 o C, where the signal intensity was dependent on the irradiation dose. Electron spin resonance (ESR) measurement was suitable for raisins and dried mangos, resulting in dose-dependent radiation-induced sugar radical signals.