硅藻土负载石榴皮提取物抗菌复合材料的制备与研究

Preparation and Research on Diatomite-Ingredient of Pomegranate Peel Antibacterial Composite Material

为促进石榴皮资源广泛应用,本实验采用超声波提取法对石榴皮进行提取,以硅藻土作为载体负载石榴皮提取物。通过单因素实验得最佳提取条件:乙醇浓度70%,料液比1∶15,石榴皮粉过200目筛,超声提取时间30 min,活性成分得率为8.34%。对硅藻土原土和Al(NO3)3改性硅藻土负载石榴皮提取物进行研究,实验得改性硅藻土对石榴皮提取物负载量高于原土,磁力搅拌8 h改性硅藻土负载量为170 mg/g而硅藻原土仅为45 mg/g。利用振荡法进行抗菌检测,发现石榴皮提取物(浓度为0.1 mL石榴皮浸膏/1 mL去离子水)对大肠杆菌和金黄色葡萄球菌具有很好的抑菌效果,37℃恒温振荡10 h抑菌率达100%;改性硅藻土负载石榴皮提取物(浓度为0.1 g/mL)对两种菌种有一定程度的抑制效果,对金黄色葡萄球菌作用较强,37℃恒温振荡10 h抑菌率达100%。对样品进行分析表征:由SEM、BET测试结果可知改性硅藻土表面及内部明显附着物质;由FT-IR分析及实验现象可知改性硅藻土表面及内部物质为石榴皮成分,石榴皮提取物与硅藻土表面Al3+发生络合反应取代硝酸根;由Zeta电位分析可知改性硅藻土与石榴皮提取物之间的静电作用也促进了负载过程,因此改性硅藻土对石榴皮提取物的负载是物理吸附与化学吸附共同作用的结果。

In order to extensively utilize pomegranate peel resources,diatomite was used as carrier to immobilize antibacterial ingredient what extracted from pomegranate peel by ultrasonic method.The optimal extract conditions were obtained by single factor experiment:the concentration of ethanol solvent was 70%,solid-liquid ratio(g-mL)was 1-15,the particle size of pomegranate peel was 200 mesh sieve and the processing time was 30 min.The extraction efficiency of active ingredient from pomegranate peel was 8.34%under these conditions.And the properties of raw and modified diatomite adsorbed the extracts were researched respectively.The adsorbent loading of modified diatomite(170 mg/g)was higher than the raw diatomite(45 mg/g)after magnetic stirred for 8 h.Then the antimicrobial properties against E.coli and S.aureus of the extracts and the composite materials were tested respectively.The experimental results showed that the inhibition rate of extracts against E.coli and S.aureus also reached 100%at 37℃for 10 h in a shaking incubator and the concentration of extracts was 0.1 mL/mL(extracts-deionized water).Meanwhile,the modified diatomite composite material exhibited a stronger inhibiting effect against S.aureus than E.coli,and the inhibition rate against S.aureus reached 100%at a concentration of 0.1 g/mL.After that these samples were characterized by scanning electron microscopy(SEM),FTIR spectrum,Zeta potential and Brunauer-Emmett-Teller(BET).The surface properties of specimens indicated that something adhering onto the surface and interior of modified diatomite obviously.The results of FTIR analysis and experimental phenomenon showed the substance adhered on diatomites were ingredients of pomegranate peel,and N0 3_was replaced by the ingredients of pomegranate peel through complex reaction between extracts and Al3+on modified diatomite.The Zeta potential analysis showed the electrostatic interaction of extracts with modified diatomite promoted the adsorption of extracts onto modified diatomite.Therefore,the loading of extracts by modified diatomite was a combination of physical and chemical adsorption.