【目的】检测孜然是否经过辐照处理并估算孜然原初吸收剂量。【方法】以孜然为对象,采用电子自旋共振波谱(ESR)技术研究孜然在0—15.0 kGy内ESR波谱特征变化,分析辐照剂量与信号强度的关系以及贮藏时间对自由基浓度的影响,并采用附加剂量法估测孜然样品的原初吸收剂量。【结果】辐照后孜然的ESR波谱信号强度随辐照剂量增加而增大,经过220 d贮藏期后仍能应用ESR波谱法检测孜然是否经过辐照处理。附加剂量法能够用于辐照孜然的剂量估算,其中利用3次多项式在不同贮藏时间里(10 d、20 d和30 d)拟合估算出的每个样品的剂量值与原初剂量的偏差均在1 kGy内,比用对数方程拟合估算出的剂量值更准确。【结论】ESR波谱技术能够定性和定量鉴定辐照孜然。
【Objective】The objective of this study is to detect whether or not the cumin has been irradiated and estimate the initial absorbed dose of cumin.【Method】The cumin was used as an experimental material to investigate the feature changes of ESR spectrum and the relationship between ESR intensity and irradiation dose in the range of 0 to 15.0 kGy and the initial absorbed dose of cumin was assessed by using the dose-additive method.【Result】The ESR signal intensity of irradiated cumin increased with the increasing of the absorbed dose,and even after 220 days ESR method could also be used to identify whether or not the cumin has been irradiated.The dose additive method could be used for a reliable evaluation of the absorbed dose in cumin and the deviation between the initial dose and the dose estimated by using 3rd degree polynomial function at different storage times(10,20 and 30 days) after initial irradiation was all less than 1 kGy,the estimated doses of samples using the 3rd polynomial function were more close to the actual doses than using the exponential function.【Conclusion】The ESR technique could be used as a qualitative and quantitative method to identify irradiated cumin.