壁材对方竹叶黄酮微胶囊结构及抗氧化性能的影响

本文以麦芽糊精、阿拉伯胶、明胶、大豆分离蛋白、月桂酸单甘酯为壁材，通过喷雾干燥制备方竹叶黄酮微胶囊，利用扫描电镜、激光粒度仪对其结构进行表征，并以理化性质及抗氧化活性为指标，对比5种壁材的包埋效果及微胶囊性能。结果表明:阿拉伯胶制备微胶囊的包埋率最高（91.23%±1.00%），堆积密度最高（0.53±0.01 g/cm3），休止角最小（33.27°±1.20°），含水量最低（5.33%±0.28%），并具有良好的流动性及储存性能；微胶囊粒径分布从大到小依次为:月桂酸单甘酯（22.87 μm）>大豆分离蛋白（15.65 μm）>麦芽糊精（14.26 μm）>明胶（8.95 μm）>阿拉伯胶（6.96 μm）；扫描电镜结果显示，阿拉伯胶制备的微胶囊呈球形且表面较为完整光滑；在体外抗氧化活性及还原性实验中，阿拉伯胶制备的微胶囊抗氧化活性及还原性较高，其清除DPPH自由基的IC₅₀为364.30 μg/mL。综上，阿拉伯胶制备的方竹叶黄酮微胶囊性质明显优于其他4种壁材微胶囊产品，为开发功能更加稳定的方竹叶黄酮产品提供技术支撑。

Effects of Wall Materials on the Structure and Antioxidant Activities of the Bamboo Leaves Flavonoids Microcapsules

In this experiment, the bamboo leaves flavonoids microcapsules were prepared by spray-drying using maltodextrin, arabic gum, gelatin, soy protein isolate and monosaccharide laurate as wall materials. The properties and encapsulation effect of microcapsules prepared by five wall materials were investigated by scanning electron microscope(SEM), laser particle size distribution, physicochemical properties and antioxidant activity. The results showed that microcapsules prepared with arabic gum had the highest encapsulation rate(91.23%±1.00%), the highest stacking density(0.53±0.01 g·cm?3), the lowest resting angle(33.27°±1.20°), and the lowest moisture content(5.33%±0.28%). These microcapsules had good fluidity and storage performance. The particle size distribution resulted in descending order as the following monosaccharide laurate(22.87 μm), soybean protein isolate(15.65 μm), maltodextrin(14.26 μm), gelatin(8.95 μm), and arabic gum(6.96 μm). The results of SEM showed that the microcapsule prepared by arabic gum was spherical and the surface was relatively smooth. The microcapsules prepared by arabic gum had higher antioxidant activity and reducibility in vitro antioxidant activity and reducibility experiments, and its IC₅₀ of DPPH radical scavenging was 364.30 μg/mL. In conclusion, the properties of bamboo leaves flavonoids microcapsules prepared with arabic gum were obviously better than those of other four wall materials microcapsules. The results could provide technical support for the development of more stable functions of the flavonoids of fang bamboo leaves.