Chen Jiazi, Lee Wan Jun, Qiu Chaoying, Wang Shaolin, Li Guanghui, Wang Yong
JNU-UPM International Joint Laboratory on Plant Oil Processing and Safety, Department of Food Science and Engineering, Jinan University, Guangzhou, China.
Front Bioeng Biotechnol. 2020 May 19;8:466. doi: 10.3389/fbioe.2020.00466. eCollection 2020.
Novozym 435, an immobilized lipase from B. (CALB), was used as a biocatalyst for the synthesis of high purity medium chain diacylglycerol (MCD) in a bubble column reactor. In this work, the properties of the MCD produced were characterized followed by determining its practical application as an emulsifier in water-in-oil (W/O) emulsion. Two types of MCDs, namely, dicaprylin (C-DAG) and dicaprin (C-DAG), were prepared through enzymatic esterification using the following conditions: 5% Novozym 435, 2.5% deionized water, 60°C for 30 min followed by purification. A single-step molecular distillation (MD) (100-140°C, 0.1 Pa, 300 rpm) was performed and comparison was made to that of a double-step purification with MD followed by silica gel column chromatography technique (MD + SGCC). Crude C-DAG and C-DAG with DAG concentration of 41 and 44%, respectively, were obtained via the immobilized enzyme catalyzing reaction. Post-purification via MD, the concentrations of C-DAG and C-DAG were increased to 80 and 83%, respectively. Both MCDs had purity of 99% after the MD + SGCC purification step. Although Novozym 435 is a non-specific lipase, higher ratios of 1,3-DAG to 1,2-DAG were acquired. Via MD, the ratios of 1,3-DAG to 1,2-DAG in C-DAG and C-DAG were 5.8:1 and 7.3:1, respectively. MCDs that were purified using MD + SGCC were found to contain 1,3-DAG to 1,2-DAG ratios of 8.8:1 and 9.8:1 in C-DAG and C-DAG, respectively. The crystallization and melting peaks were shifted to higher temperature regions as the purity of the MCD was increased. Dense needle-like crystals were observed in MCDs with high purities. Addition of 5% C-DAG and C-DAG as emulsifier together in the presence of 9% of hydrogenated soybean oil produced stable W/O emulsion with particle size of 18 and 10 μm, respectively.
诺维信435（一种来自柱状假丝酵母的固定化脂肪酶，CALB）被用作生物催化剂，在鼓泡塔反应器中合成高纯度中链甘油二酯（MCD）。在这项工作中，对所生产的MCD的性质进行了表征，随后测定了其作为油包水（W/O）乳液乳化剂的实际应用。通过酶促酯化反应，在以下条件下制备了两种类型的MCD，即二辛酸甘油酯（C-DAG）和二癸酸甘油酯（C-DAG）：5%诺维信435、2.5%去离子水、60°C反应30分钟，然后进行纯化。进行了单步分子蒸馏（MD）（100 - 140°C、0.1 Pa、300 rpm），并与先进行分子蒸馏然后采用硅胶柱色谱技术的两步纯化法（MD + SGCC）进行了比较。通过固定化酶催化反应分别获得了DAG浓度为41%和44%的粗C-DAG和C-DAG。经MD纯化后，C-DAG和C-DAG的浓度分别提高到了80%和83%。在MD + SGCC纯化步骤之后，两种MCD的纯度均达到99%。尽管诺维信435是一种非特异性脂肪酶，但获得了更高比例的1,3 - DAG与1,2 - DAG。通过MD，C-DAG和C-DAG中1,3 - DAG与1,2 - DAG的比例分别为5.8:1和7.3:1。发现使用MD + SGCC纯化的MCD在C-DAG和C-DAG中1,3 - DAG与1,2 - DAG的比例分别为8.8:1和9.8:1。随着MCD纯度的提高，结晶峰和熔融峰向更高温度区域移动。在高纯度的MCD中观察到密集的针状晶体。在9%氢化大豆油存在下，分别添加5%的C-DAG和C-DAG作为乳化剂，可产生粒径分别为18和10μm的稳定W/O乳液。
