紫苏精油微囊粉的生物活性及结构表征

以紫苏精油为原料，研究对比阿拉伯胶、辛烯基琥珀酸淀粉酯两种壁材不同处理制备紫苏精油微囊粉的抗氧化性和抑菌活性，并通过扫描电镜（SEM）、傅里叶变换红外光谱（FT-IR）、热重分析（TGA）等对其结构进行表征。结果表明：随紫苏精油微囊粉用量增加，抗氧化能力逐步增强，在微囊粉用量同为7 mg时，辛烯基琥珀酸淀粉酯制备微囊粉对DPPH自由基、羟基自由基和ABTS自由基均的清除能力分别达到89.19%，84.58%和97.93%。最佳用量为5 mg下，辛烯基琥珀酸淀粉酯壁材紫苏精油微囊粉对枯草芽孢杆菌、大肠杆菌两种细菌的抑菌效果最好，用量为4 mg下，对金黄色葡萄球菌的抑菌效果最好，对番茄早疫菌和西瓜枯萎菌两种真菌的抑菌率分别达到31.58%和90.48%。扫描电镜观察及红外光谱、热重分析表明，辛烯基琥珀酸淀粉酯紫苏精油微囊粉颗粒呈圆球形，表面完整且有较浅凹陷，包埋过程仅为物理包被。研究结果表明，辛烯基琥珀酸淀粉酯制备紫苏精油微囊粉抗氧化性强，抑菌效果好，具有广阔的应用前景。

Biological Activities and Structure Characterization of Perilla Essential Oil Microcapsule Powder

Using Perilla essential oil as raw material, the antioxidant and antibacterial activities of Perilla essential oil microcapsule powder prepared by different treatment of two wall materials, gum Arabic and octenyl starch ester, were studied and compared. The structure of the microcapsule powder was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The results showed that with the increase of the amount of microcapsule powder, the antioxidant capacity was gradually enhanced. When the amount of microcapsule powder was 7 mg, the scavenging ability of DPPH radical, hydroxyl radical and ABTS radical prepared by octenyl succinate starch ester reached 89.19%, 84.58% and 97.93%, respectively. When the optimum dosage was 5 mg, the antibacterial effect of the octenyl succinate starch ester wall material Perilla essential oil microcapsule powder on B. subtilis and E. coli was the best; when the dosage was 4 mg, the bacteriostatic effect on S. aureus was the best; the antibacterial rates of tomato early disease bacteria and watermelon wilt bacteria reached 31.58% and 90.48% respectively. Scanning electron microscopy (SEM), infrared spectroscopy (IR) and thermogravimetric analysis (TG) showed that the octenyl succinate starch ester perilla essential oil microcapsules were spherical, with a complete surface and shallow depression, and the embedding process was only physical encapsulation. The results showed that the microcapsule powder of Perilla essential oil prepared by octenyl succinic acid starch ester had strong oxidation resistance and good antibacterial effect, and had broad application prospect.