Abstract The objective of our work was to investigate the specificity of the European standard method of analysis EN 1787:2000 “Detection of irradiated food-containing cellulose by Electron Spin Resonance (ESR) spectroscopy”. Butz and Hildebrand (2006) have expressed doubts about the specifity of the methods when applied to walnuts and hazelnuts in shells. To this end, walnuts and hazelnuts in shell were bleached with hydrogen peroxide at 20% and irradiated by electron beam (2.2 MeV). The samples were then analysed, using the EN 1787 method, by Aerial (Strasbourg) and Chemical and Veterinary Office Karlsruhe (CVUA Karlsruhe). Electron Spin Resonance (ESR) measurements were performed from the first week up to 12 months after treatment. The results obtained showed that the spectra of bleached walnuts and hazelnuts could be mixed up with the irradiated ones, as a pair of satellite signals with a distance of about 6 mT appears. However, the intensity ratio of these two satellite signals is equal to one for irradiated samples but significantly greater than one for bleached samples regardless of the irradiation dose or storage duration tested. This ratio could thus be used to distinguish bleached from irradiated hazelnuts and walnuts when EN 1787 is used as detection method.

中文翻译：

---

ESR光谱法鉴别漂白和辐照核桃和榛子

摘要 我们工作的目的是研究欧洲标准分析方法 EN 1787:2000“通过电子自旋共振 (ESR) 光谱检测辐照食品中的纤维素”的特异性。Butz 和 Hildebrand (2006) 对应用于带壳核桃和榛子的方法的特异性表示怀疑。为此，将带壳的核桃和榛子用 20% 的过氧化氢漂白，并用电子束 (2.2 MeV) 照射。随后，Aerial（斯特拉斯堡）和卡尔斯鲁厄化学与兽医办公室（CVUA Karlsruhe）使用 EN 1787 方法对样品进行了分析。电子自旋共振 (ESR) 测量在治疗后的第一周至 12 个月内进行。结果表明，漂白核桃和榛子的光谱可能与辐照的光谱混淆，出现一对距离约6 mT的卫星信号。然而，这两个卫星信号的强度比对于辐照样品等于 1，但对于漂白样品显着大于 1，无论测试的辐照剂量或储存持续时间如何。因此，当使用 EN 1787 作为检测方法时，该比率可用于区分漂白榛子和辐照榛子和核桃。