核磁共振氢谱法分析食用油氧化产物

Analysis of oxidation product in edible oil by ~1H nuclear magnetic resonance spectroscopy

高场核磁共振近年来已应用到油脂品质检测领域。通过高温加热实验加速油脂劣变,制备不同氧化程度大豆油样品,利用高场核磁共振仪采集样品的氢谱数据,积分氢谱各指纹峰,计算各时间点油脂氧化产物的相对含量。结果表明:所有氧化产物与自由基链式反应机理的引发和传递阶段相符合;氧化全程顺式环氧化物含量高于反式,仲醇含量于伯醇,醛类物质中反-2-烯醛含量最高,加热6 h后其含量高达17. 94 mmol/mol。高场核磁共振氢谱技术在食用油品质快速检测领域具备潜在应用价值。

High field nuclear magnetic resonance( NMR) has been applied to the field of oil quality detection in recent years. The oil degradation was accelerated by the high temperature heating experiment and soybean oil samples with different oxidation degrees were prepared. The hydrogen spectrum datas of oils were collected by NMR and their fingerprint peaks were integrated. The relative contents of the oxidation products in oil were calculated at each time point. The results showed that the change of oxidation products was consistent with the trend of initiation and delivery stages according to the radical chain reaction mechanism. The content of cis-epoxide was higher than that of trans-epoxide in the whole process and the content of secondary alcohol was higher than that of primary alcohol. The content of trans-2-aldehyde in aldehydes was the highest,reaching 17. 94 mmol/mol after heating for 6 h. High field NMR spectroscopy showed potential application value in the rapid detection of edible oil quality.