The generation, accumulation and decay of free radicals in six varieties of cheese, irradiated (0–4 kGy) in an electron accelerator, have been studied by electron spin resonance (ESR) spectroscopy. Remarkably, the ESR spectra of all untreated cheeses showed only one singlet signal with a g-factor of 2.0064 ± 0.0005. Surprisingly, the ESR spectra of irradiated samples presented a new signal with g-factor of 2.0037 ± 0.0003 which was independent of the type of cheese, and which might be due to free radicals from the radiolysis of proteins. Surface regression models (P < 0.0001) established the relationship among signal intensity, absorbed dose (0, 1, 2 and 4 kGy) and storage time (0–180 days) for the different types of cheese. Results suggested that the analysis by ESR (or electron paramagnetic resonance, EPR) is suitable to evaluate, either qualitatively or quantitatively, the irradiation treatment of different types of cheese.

通过电子自旋共振（ESR）光谱研究了六种奶酪中自由基的产生，积累和衰减，这些奶酪在电子促进剂中被辐照（0–4 kGy）。值得注意的是，所有未经处理的奶酪的ESR谱图仅显示出一个单线态信号，其g因子为2.0064±0.0005。令人惊讶地，照射的样品的ESR谱带有新的信号克-因子的2.0037±0.0003这是独立的干酪的类型，并且这可能是由于来自蛋白质的放射分解自由基。曲面回归模型（P <0.0001）建立了不同类型奶酪的信号强度，吸收剂量（0、1、2和4 kGy）与存储时间（0-180天）之间的关系。结果表明，通过ESR（或电子顺磁共振，EPR）进行的分析适合于定性或定量评估不同类型奶酪的辐照处理。