基于低场二维核磁共振的油茶籽油鉴别与掺兑检测

低场二维核磁共振(LF-2D-NMR)图谱可以提供丰富的弛豫信息。在研究8种食用油处于新鲜及氧化状态下的低场T_1-T_2二维核磁图谱信息的基础上,结合化学计量学方法建立了鉴别油茶籽油与其他食用油、氧化食用油的定性模型及油茶籽油掺兑玉米油、大豆油、葵花籽油的定量模型。结果表明,不同种类食用油的LF-2D-NMR信息存在明显差异,氧化食用油与正常食用油的LF-2D-NMR信息有显著区别,LF-2D-NMR可提供更为丰富的特征信息。基于样品的低场T_1-T_2二维核磁图谱信息建立的油茶籽油与其他7种食用油或8种氧化食用油的偏最小二乘判别模型的分类效果优秀,模型判别正确率均为100%。此外,还建立了油茶籽油掺兑玉米油、大豆油、葵花籽油的定量预测模型,R~2分别为0.988、0.962、0.941。研究表明,低场T_1-T_2二维核磁共振技术可用于食用油种类判别及油茶籽油掺兑分析。

Authenticity and Adulteration Detection of Camellia Oil Based on LF-2D-NMR

Camellia oil,as a healthy and high-quality vegetable oil,has great economic value while being popular in the market.Low-field nuclear magnetic resonance(LF NMR)technology is widely used in the field of food detection due to its rapid and non-destructive characteristics,but the current application of LF NMR technology in the detection of counterfeit and adulteration of camellia oil remains to be studied.Low-field two-dimensional nuclear magnetic resonance(LF 2D NMR)can provide abundant relaxation information.Based on the study of the T 1 T 2 LF 2D NMR spectrum information of eight edible oils in the fresh and oxidized state,the identification models of camellia oil with other edible oils,oxidized edible oils and the quantitative models of camellia oil blended with corn oil,soybean oil and sunflower oil was established combined with chemometric methods.The results showed that the LF 2D NMR information of different kinds of edible oils was obviously different;the LF 2D NMR information between oxidized edible oil and normal edible oil was significantly different;LF 2D NMR can provide richer characteristic information.The PLS DA model of camellia oil with other seven kinds of edible oils or eight kinds of oxidized edible oils had excellent classification effect,the accuracy of discrimination both were 100%.In addition,PLS model of camellia oil blended with corn oil,soybean oil,and linseed oil were also established.Studies showed that low-field T 1-T 2 two-dimensional nuclear magnetic resonance technology can play an important role in the identification of edible oil types and camellia oil adulteration.