Thermoluminescence characterization of isolated minerals to identify oranges exposed to c-ray, e-beam, and X-ray for quarantine applications Deokjo Jo • Bhaskar Sanyal • Ju-Woon Lee • Joong-Ho Kwon Received: 15 April 2014 Ó Akade ´miai Kiado ´, Budapest, Hungary 2014 Abstract Identification of irradiated fruits is of paramount importance to address the limitation of irradiation technology because of varying national and international regulations. Thermoluminescence (TL) analysis was carried out to identify oranges irradiated with c-ray, electron beam and X-ray. Non- irradiated samples exhibited background TL signals, but all the irradiated samples showed defined TL glow curves char- acterized by a prominent peak at 158–163 °C. Characteriza- tions of the irradiated standard minerals showed that feldspars were the major contributors to the TL emission and stable TL signals revealed a successful detection of irradiated oranges even after a prolonged storage. Keywords Food irradiation detection Á Thermoluminescence Á Feldspars Á Quartz Introduction Large quantities of fruits, vegetables, and nuts are pro- duced in South Korea. However, fruits and nuts imported from the United States are finding increasing markets in South Korea because of their quality, relatively low cost, and variety. In 2010, South Korea’s fresh fruit and vege- table imports rose significantly because of some recovery from the economic downturn of the previous year. Fresh fruit imports from the United States were worth $205 million, up by 56 % from that of the previous year, and oranges were the major item in this trade [1]. Growth is likely to continue over the next decade. However, the import of oranges from other countries is associated with the risk of migration of potentially damaging organisms such as insect pests to new areas. To overcome this barrier to international trade known as quarantine barrier, tech- nological solutions are being developed worldwide. Food irradiation technology could be one of the potential solu- tions to this problem. The safety, wholesomeness, and nutritional adequacy of irradiated foods are now well documented and accepted by all major health and food authorities [2]. Food irradiation technology is being used commercially in more than 55 countries around the world to improve hygiene quality [3]. Further developments in the design and adaptation of uses of machine radiation sources (e-beam facilities and X-ray machines) [4–6] are also being investigated in quarantine treatments of various food commodities, including citrus fruits such as oranges. However, various national and international regulations with mandatory labeling requirements restrict the general use of this technology. The acceptability of irradiated food commodities, especially in the commercial domain of international trade, needs reliable identification methods to enforce regulations and traceability [7]. The development of reliable methods to distinguish irradiated foods from non-irradiated foods is therefore essential in view of the growing interest by the food industry in irradiation technology. Bhaskar Sanyal—On leave from Food Technology Division, Bhabha Atomic Research Centre, Mumbai, India. D. Jo Á B. Sanyal Á J.-H. Kwon (&) School of Food Science and Biotechnology, Kyungpook National University, Daegu 702-701, Korea e-mail: jhkwon@knu.ac.kr B. Sanyal Food Technology Division, Bhabha Atomic Research Centre, Mumbai, India J.-W. Lee Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeonbuk 580-185, Korea 123 J Radioanal Nucl Chem DOI 10.1007/s10967-014-3421-6