论文应用1H-NMR研究了葵花籽油65 ℃贮藏过程中氧化产物（共轭烯、醛类、氧化物、芳香烃、游离酸相对含量）的变化规律，并与低场核磁共振（LF-NMR）弛豫特性中的S21的变化进行了相关性分析。1H-NMR结果表明，在65 ℃贮藏过程中，油样的初级氧化产物随贮藏时间的延长呈先增加后减小的趋势，与氢过氧化物相比，氢过氧化物-共轭二烯优先降解；次级氧化产物及水解产物如醛、环氧化物、游离脂肪酸等随贮藏时间呈良好指数关系（R2>0.96），芳香烃则随贮藏时间呈先增加后减小的趋势。而LF-NMR检测所得到的油样的S21随贮藏时间延长呈良好的指数增加趋势（R2=0.99）。相关性分析表明，氧化物、游离脂肪酸与S21的相关性最高，模型验证合理可靠。该结果可为研究S21特征峰的表征物质、提高LF-NMR油脂品质判别率提供研究参考及有益思路。

1H nuclear magnetic resonance (1H-NMR) was used to study change patterns associated with relative content of oxidation products (conjugated olefins, aldehydes, oxides, aromatic hydrocarbons, and free fatty acids) produced by the process of thermal oxidation during storage of sunflower oil at 65 ℃. Correlation analysis with S21 changes in low-field (LF)-NMR relaxation was conducted. The 1H-NMR results indicated that the amount of primary oxidation products increased initially and then decreased with time, where hydroperoxide- conjugated dienes were preferentially degraded as compared to hydrogen peroxides. The amount of secondary oxidation products and hydrolysates such as aldehydes, epoxides, and free fatty acids increased exponentially with time (R2 > 0.96), whereas the amount of aromatic hydrocarbons also increased and then decreased with time. The LF-NMR peak area S21 for the oil sample increased exponentially (R2 = 0.99) with time. Correlation analysis showed that oxides and free fatty acids had the highest correlation with S21, which was proved reasonable and reliable by model validation. The results could provide a foundation to further explore the characteristic peak S21 such that the quality of edible oil could be improved using the LF-NMR results as reference.

国家自然科学基金（NSFC31201365）；上海市科委重点攻关项目（11142200403）；上海市教委科研创新项目（11YZ109）