Huang Xiaoli, Zhao Yuehan, Hou Zhaohua
College of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), No. 3501 Daxue Road, Changqing District, Jinan 250353, China.
Foods. 2021 Aug 19;10(8):1925. doi: 10.3390/foods10081925.
Foxtail millet () bran oil is rich in linoleic acid, which accounts for more than 60% of its lipids. Ethyl linoleate (ELA) is a commercially valuable compound with many positive health effects. Here, we optimized two ELA processing steps, urea complexation (UC) and molecular distillation (MD), using single-factor and response surface analyses. We aimed to obtain a highly concentrated ELA at levels that are permitted by current regulations. We identified the optimal conditions as follows: 95% ethanol-to-urea ratio = 15:1 (/), urea-to-fatty acid ratio = 2.5:1 (/), crystallization time = 15 h, and crystallization temperature = -6 °C. Under these optimal UC conditions, ELA concentration reached 45.06%. The optimal MD purification conditions were established as follows: distillation temperature = 145 °C and vacuum pressure = 1.0-5.0 × 10 mbar. Under these conditions, ELA purity increased to 60.45%. Together, UC and MD were effective in improving the total concentration of ELA in the final product. This work shows the best conditions for separating and purifying ELA from foxtail millet bran oil by UC and MD.
谷子（）麸皮油富含亚油酸，其在脂质中所占比例超过60%。亚油酸乙酯（ELA）是一种具有许多积极健康影响的商业上有价值的化合物。在此，我们通过单因素和响应面分析优化了两个ELA加工步骤，即尿素络合（UC）和分子蒸馏（MD）。我们旨在获得当前法规允许水平的高浓度ELA。我们确定的最佳条件如下：乙醇与尿素的比例为95% = 15:1（/），尿素与脂肪酸的比例为2.5:1（/），结晶时间为15小时，结晶温度为-6°C。在这些最佳UC条件下，ELA浓度达到45.06%。确定的最佳MD纯化条件如下：蒸馏温度为145°C，真空压力为1.0 - 5.0×10毫巴。在这些条件下，ELA纯度提高到60.45%。UC和MD共同有效地提高了最终产品中ELA的总浓度。这项工作展示了通过UC和MD从谷子麸皮油中分离和纯化ELA的最佳条件。
