Xiao Lin, Wang Shang, Wang Yi, Wang Binchen, Ji Chaofan, Lin Xinping, Liang Huipeng, Zhang Sufang, Xu Xianbing, Dong Liang
School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, Liaoning, China.
China Resources Snow Beer, Beijing 100000, Beijing, China.
Food Chem X. 2023 Jun 7;19:100737. doi: 10.1016/j.fochx.2023.100737. eCollection 2023 Oct 30.
Oleic acid oxidation is one of the main sources of food flavor compounds. Volatile profiling was investigated using thermal desorption cryo-trapping combined with gas chromatography-mass spectrometry to analyze the volatile composition of oleic acid oxidation. A total of 43 volatile compounds, including aldehydes (11), ketones (2), alcohols (5), furans (2), acids (8), ester (12) and alkane (3) were identified from oleic acid during heating. Then, density functional theory (DFT) was applied to analyze the oxidative mechanism of oleic acid during heating. A total of 30 reactions were obtained and grouped into the peroxide (ROOH), alkoxy radical (RO•), and peroxide radical (ROO•) pathways. The structures of intermediates, transition states (TS), and products in each reaction were also determined. Results show that the branch chemical reactions were the key reactions in different reaction pathway. Moreover, the reaction priority of the thermal oxidation reaction of oleic acid was the peroxide radical mechanism > the peroxide mechanism > the alkoxy radical mechanism.
油酸氧化是食品风味化合物的主要来源之一。采用热脱附低温捕集结合气相色谱 - 质谱联用技术对挥发性成分进行分析，以研究油酸氧化的挥发性组成。在加热过程中，从油酸中鉴定出总共43种挥发性化合物，包括醛类（11种）、酮类（2种）、醇类（5种）、呋喃类（2种）、酸类（8种）、酯类（12种）和烷烃类（3种）。然后应用密度泛函理论（DFT）分析油酸在加热过程中的氧化机理。共获得30个反应，并分为过氧化物（ROOH）、烷氧基自由基（RO•）和过氧自由基（ROO•）途径。还确定了每个反应中的中间体、过渡态（TS）和产物的结构。结果表明，支链化学反应是不同反应途径中的关键反应。此外，油酸热氧化反应的反应优先级为过氧自由基机理＞过氧化物机理＞烷氧基自由基机理。
