短碳链结构磷脂在Zn-Fe3O4@SiO2催化作用下的制备及其性能

Catalytic production of short-chain structured phospholipids via Zn-Fe3O4@SiO2 and their physicochemical properties

摘要:

通过溶胶-凝胶法和浸渍法制备了负载Zn的二氧化硅包覆四氧化三铁（Zn-Fe3O4@SiO2），采用SEM、TEM、XPS、Py-FTIR、VSM、EDS等对其进行表征。将Zn-Fe3O4@SiO2用于催化大豆卵磷脂（SLs）与短碳链脂肪酸（丙酸和丁酸）间的酸解反应来制备新型短碳链结构磷脂（SCSPLs）乳化剂，并对SCSPLs进行性能测定。结果表明，核壳结构Zn-Fe3O4@SiO2磁性微球负载了大量的活性Zn组分，因而可高效催化制备SCSPLs；在m(SLs)∶m(C3:0)∶m(C4:0)=1∶4∶4、催化剂用量为原料总质量的5%、反应温度为50 ℃、反应时间为5 h的条件下，SCSPLs的短碳链脂肪酸接入率可高达78.15%±1.08%（丙酸和丁酸的接入率分别为35.43%±0.62%和42.72%±0.55%），且Zn-Fe3O4@SiO2可通过外加磁场进行简单分离及循环5次而无明显失活；与SLs原料相比，SCSPLs的乳化性、分散性和氧化稳定性等均得到极大提高。

Abstract:

A kind of zinc-loaded silica-coated iron oxide (Zn-Fe3O4@SiO2) material was prepared by sol-gel and impregnation methods, and their textural and magnetic properties were characterized by SEM, TEM, XPS, Py-FTIR, VSM and EDS techniques. The as-prepared Zn-Fe3O4@SiO2 was used to catalyze the acidolysis of soybean lecithins (SLs) with short-chain fatty acids (propionic acid and butyric acid) to synthesize novel emulsifiers of short-chain structured phospholipids (SCSPLs). Otherwise, the main physicochemical properties of the targeted SCSPLs were studied as well. Resultingly, it was identified that the thus-synthesized core-shell Zn-Fe3O4@SiO2 magnetic microspheres contained amounts of active zinc moieties, which effectively facilitated the synthesis of SCSPLs. When the m(SLs)∶m(C3:0)∶m(C4:0)=1∶4∶4, the catalyst dosage was 5% of total mass of raw materials, the reaction temperature was 50 ℃, and the reaction time was 5 h, the maximum short-chain fatty acid incorporation of SCSPLs reached 78.15%±1.08% with 35.43%±0.62% of propionic acid and 42.72%±0.55% of butyric acid. Meanwhile, Zn-Fe3O4@SiO2 could be easily separated with an external magnetic field and be recycled for 5 times without obvious deactivation. Moreover, the targeted SCSPLs showed greatly enhanced emulsifying and dispersing properties, and oxidative stability in comparison with raw SLs.