Xie Wenlei, Zang Xuezhen
School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001, PR China.
School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001, PR China.
Food Chem. 2017 Jul 15;227:397-403. doi: 10.1016/j.foodchem.2017.01.082. Epub 2017 Jan 18.
Hydroxyapatite-encapsulated γ-FeO nanoparticles were prepared, and lipase from Candida rugosa was then covalently bound onto the magnetic materials via covalent linkages. The magnetic carrier and immobilized lipase were characterized by enzyme activity assays, XRD, FT-IR, TEM, VSM and N adsorption-desorption techniques. Results demonstrated that γ-FeO nanoparticles were coated with the hydroxyapatite, and the lipase was indeed tethered to the magnetic carriers without damage to their structure. The immobilized lipase showed a strong magnetic responsiveness and displayed high catalytic activities towards the interesterification of soybean oil. The interesterified products were evaluated for their total fatty acid (FA) composition, slip melting point (SMP), iodine value, triacylglycerols (TAGs) profile and FA composition at sn-2 position in TAGs. The FA positional distributions and TAG species significantly changed after the enzymatic interesterification. Besides this, the interesterified products showed an obvious reduction in their SMP in comparison with the physical blends.
制备了羟基磷灰石包裹的γ-FeO纳米颗粒,然后通过共价键将皱褶假丝酵母脂肪酶共价结合到磁性材料上。通过酶活性测定、XRD、FT-IR、TEM、VSM和N吸附-脱附技术对磁性载体和固定化脂肪酶进行了表征。结果表明,γ-FeO纳米颗粒被羟基磷灰石包覆,脂肪酶确实被 tethered 到磁性载体上,且其结构未受损。固定化脂肪酶表现出很强的磁响应性,并对大豆油的酯交换反应显示出高催化活性。对酯交换产物的总脂肪酸(FA)组成、滑熔点(SMP)、碘值、三酰甘油(TAGs)谱以及TAGs中sn-2位的FA组成进行了评估。酶促酯交换后,FA的位置分布和TAG种类发生了显著变化。除此之外,与物理共混物相比,酯交换产物的SMP明显降低。