1H nuclear magnetic resonance (NMR) fingerprints and low-field- nmr relaxation properties of sunflower oil during thermal oxidation

作者：Lu Hai Yan; Wang Xin^*; Zhao Ting Ting; Liu Bao Lin

来源：Modern Food Science and Technology, 2014, 30(8): 43-50.

• Characteristic peaks
• Conjugated dienes
• Correlation analysis
• Nuclear magnetic resonance(NMR)
• Oxidation products
• Peak area
• Secondary oxidation products
• Thermal oxidation

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 S21changes 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 S21for 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 S21such that the quality of edible oil could be improved using the LF-NMR results as reference.

• 出版日期2014