芦笋老茎中黄酮类物质的提取工艺优化及其微胶囊的性质研究

目的 优化芦笋老茎中黄酮类物质的提取工艺条件,提高芦笋副产物的高值化利用率。方法 采用超声波协同酶法提取芦笋老茎中的黄酮类活性物质,以总黄酮提取率为评价指标,通过单因素试验确定芦笋老茎中的黄酮类物质的最优提取工艺,对其黄酮类物质的抗氧化活性进行评价。以海藻酸钠为壁材制备芦笋黄酮微胶囊,对其理化性质、体外模拟胃肠消化进行分析。结果 超声波协同酶法提取芦笋老茎中的黄酮类活性物质的最优提取工艺为料液比1:20(g:mL)、乙醇体积分数60%、纤维素酶添加量2%、超声功率80 W和超声时间1.5 h,此时的总黄酮提取率为0.263%,其ABTS阳离子自由基、DPPH自由基清除率IC50值分别为43.57和34.83 μg/mL,具有一定的抗氧化活性；微胶囊的粒径为(0.8±0.1)mm、含水量为3.10%、密度为0.562 g/cm³、平均包埋率为73.62%、其超微结构显示微胶囊完整、结构致密。体外模拟胃肠消化分析表明,微胶囊在肠道中的释放率为40.55%,具有定点缓慢释放有效成分的作用。结论 采用超声波辅助酶法提取芦笋老茎中的黄酮类物质具有良好效果,微胶囊品质良好,可为芦笋副产物的精深加工提供理论数据和技术支撑。

Study on the optimization of extraction technology of flavonoids from the old stem of Asparagus officinalis L. and the properties of its microcapsules

Objective To optimize the extraction technology of flavonoids from the old stem of Asparagus officinalis L., prepare the microcapsules and reveal their physical and digestive characteristics, and explore a new way of high-value utilization of Asparagus officinalis L. by-products. Methods The flavonoids from the old stem of Asparagus officinalis L. were extracted by ultrasonic-assisted enzymatic method, taking the extraction rate of total flavonoids as the evaluation index, the optimum extraction conditions of flavonoids from the old stem of Asparagus officinalis L. was determined by single factor and optimization experiment. Asparagus officinalis L. flavonoids microcapsules were prepared with sodium alginate as wall material, and their physicochemical properties and simulated gastrointestinal digestion in vitro were analyzed. Results The optimum extraction conditions of flavonoids from the old stem of Asparagus officinalis L. by ultrasonic-assisted enzymatic method were as follows: Material-liquid ratio 1:30 (g:mL), ethanol volume fraction 60%, cellulase addition 2%, ultrasonic power 80 W and ultrasonic time 1.5 h. Under these conditions, the extraction rate of total flavonoids was 0.268%. The particle size of the microcapsule was 0.8 mm, the moisture content was 3.10%, the density was 0.562 g/cm3, and the average embedding rate was 73.62%. The microcapsule was complete shape and compact structure according to the ultra structures of the electron microscope. The analysis of simulated gastrointestinal digestion in vitro showed that the release rate of microcapsules in the intestine was 40.55%, which could slowly release the active components at the fixed point. Conclusion Ultrasonic-assisted enzymatic extraction of flavonoids from the old stem of Asparagus officinalis L. has a good effect, the prepared flavonoid microcapsules have good physical and digestible properties, the related studies can provide theoretical supports for the intensive processing of Asparagus officinalis L. by-products.