鲜花生的低场核磁共振横向弛豫分析

Low Field NMR Transverse Relaxation Spectrum of Peanut

尽管低场1H-核磁共振(NMR)弛豫谱技术可以有效地获取油料作物种子中水和油脂等组分含量信息,但实现准确分析的关键前提是解决弛豫谱的标识问题。首先,通过记录鲜花生脱水过程质量随时间变化确定核磁共振测量步骤;随之,采用CPMG(Carr-Purcell-Meiboom-Gill)方法获得花生核磁共振横向弛豫数据;最后,使用连续谱迭代方法得到花生核磁共振弛豫谱。由弛豫谱峰面积与花生质量变化关系,并借助纯花生油实验结果确认了样品脂肪的核磁共振横向弛豫谱。基于单位质量干燥花生和纯花生油两者的脂肪弛豫谱峰面积之比获得与索氏抽提法相吻合的含油率。

As low field 1 H NMR relaxation can effectively measure moisture and fat in oil seed,the key problem is technology for identification of the contribution from these components respectively.The pea-nut mass change with hydrogenation is recorded for optimizing NMR measurement process.The CPMG （Carr-Purcell-Meiboom-Gill） technique was applied to obtain the NMR transverse relaxation of peanut and peanut oil samples,and the resonance relaxation spectrum was analyzed with the method of continu-ous spectrum iteration.According to the variation of relaxation spectrum peak area with peanut mass,the assignments of the relaxation peaks were determined with the results from peanut oil.The study found that the transverse relaxation spectrum peaks reflected the fat content in dry peanut.Compared with fat con-tent measured with traditional technology,the peak areas for dry fresh peanut had a positive linear corre-lation with its fat concentration.The results demonstrate that the NMR transverse relaxation spectrum can be used for determination of fat content in fresh peanut.