Lee E J, Volkov V I, Lee C H
Graduate School of Biotechnology, Korea University, 1, 5-ka, Anam-dong, Sungbuk-ku, Seoul 136-701, Korea.
J Agric Food Chem. 2001 Jul;49(7):3457-62. doi: 10.1021/jf010227t.
Free radicals in gamma-irradiated soybean paste were investigated by electron spin resonance (ESR) spectroscopy to determine the effect of temperature (77-296 K) and moisture content (1-54%) of samples irradiated at high dose (1-40 kGy). The samples were kept in liquid nitrogen (77 K) during irradiation and subsequent ESR measurements. The spectra shown at 77 K consisted of the hydrogen atom lines at low and high field and complicated symmetric spectrum. By increasing the microwave power, the line shape of ESR spectra altered, which indicated the detection of different paramagnetic centers at different microwave powers. In saturation curves, it was possible to select four types of spectra components which were different in their relaxation times. By the different irradiation doses, the change in free radical concentration showed a curvilinearly increasing relationship with irradiation dose in wet samples, whereas a proportional relationship was observed with dried samples. This might indicate that the indirect process of free radical formation was involved with the existence of free water radicals in the wet samples.
利用电子自旋共振（ESR）光谱研究了γ辐照大豆酱中的自由基，以确定高剂量（1-40 kGy）辐照样品的温度（77-296 K）和水分含量（1-54%）的影响。在辐照及随后的ESR测量过程中，将样品保存在液氮（77 K）中。77 K时显示的光谱由低场和高场的氢原子线以及复杂的对称光谱组成。通过增加微波功率，ESR光谱的线形发生变化，这表明在不同微波功率下检测到了不同的顺磁中心。在饱和曲线中，可以选择四种弛豫时间不同的光谱成分。通过不同的辐照剂量，湿样品中自由基浓度的变化与辐照剂量呈曲线增加关系，而干样品中则观察到比例关系。这可能表明自由基形成的间接过程与湿样品中自由水自由基的存在有关。
