Study of photostimulated- and thermo-luminescence characteristics for detecting irradiated kiwifruit.
Photostimulated luminescence (PSL) and thermo-luminescence (TL) analyses were conducted to detect irradiated kiwifruits. Samples were irradiated with Co-60 gamma-rays at 0-2 kGy. The freeze-dried kiwifruit peel showed 309 photon counts (PCs) for nonirradiated samples that accounted for less than the lower threshold value (700 counts/60 s, negative) and above 9306 PCs for 1 and 2 kGy-irradiated samples, which was higher than the upper threshold value (5000 counts/60 s, positive). However, PSL signals of irradiated samples remarkably decreased after 6 weeks of storage. The TL measurement using minerals isolated from the whole kiwifruit surface revealed a glow curve (TL 1) with a low intensity at 200-300 degrees C in nonirradiated samples but with a higher intensity at around 180 degrees C in irradiated samples at 1 kGy or more. The TL ratios, integrated areas of TL 1/TL 2 that was measured after 1 kGy re-irradiation for the TL 1-tested minerals, were less than 0.1 in nonirradiated samples and higher than 0.1 in irradiated ones and could verify TL 1 results. The inorganic dust minerals used were mainly composed of feldspar and quartz.
Jo
Deokjo
D
Department of Food Science and Technology, Kyungpook National University, Daegu, Korea.
Kim
Byeong-Keun
BK
Kausar
Tusneem
T
Kwon
Joong-Ho
JH
D029042:Actinidia; D005504:Food Analysis; D005514:Food Irradiation; D005638:Fruit / Q000737:chemistry*; D005720:Gamma Rays; D006358:Hot Temperature; D008027:Light; D008163:Luminescent Measurements / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors