从桑枝皮提取血管紧张素转换酶活性抑制物质的工艺条件优化

Process Optimization for Extraction of Inhibitory Substance Against Angiotensin Converting Enzyme Activity from Mulberry Branch Bark

采用超声波协同酶解法,以桑枝皮为原料提取血管紧张素转换酶(ACE)活性抑制物质,为桑枝皮资源的高附加值开发利用寻求新的技术途径。以桑枝皮提取物对ACE活性的抑制率为考核指标,利用Plackett-Burman试验设计、最陡爬坡试验、Box-Behnken试验设计和响应面法对提取工艺条件进行优化。结果表明,提取工艺各因素对桑枝皮提取物的ACE活性抑制率影响程度依次为料液质量浓度、纤维素酶用量、超声波功率和提取时间。优化的提取工艺条件为:料液质量浓度64.6g/L,纤维素酶用量3 454.3 U/g,超声波功率87 W,提取时间68 min。在此工艺条件下获得的桑枝皮提取物对ACE活性的抑制率可达到86%,其半数抑制浓度(IC50)为2.19 g/L。优化的提取工艺具有对设备的性能要求不高,操作简便等特点。

To seek new ways for development and utilization of high value-added products from mulberry branch bark, the inhibitory substance against angiotensin converting enzyme （ACE） was extracted from mulberry branch bark by ultra- sound assisted enzyme hydrolysis. The extraction conditions were optimized with Plackett-Burman experimental design, steepest ascent experiment, Box-Behnken experimental design and response surface methodology using inhibition rate of mulberry bark extract against ACE as the evaluation indicator. The results indicated that various factors of the extraction process had the following order in affecting the inhibition rate of mulberry bark extract against ACE.- mass concentration of mulberry branch bark, cellulase dosage,＇ ultrasonic power and extraction time. The optimized process condition is as follows= mulberry branch bark mass concentration 64.6 g/L, cellulase dosage 3 454.3 U/g, ultrasonic power 87 W, and extraction time 68 min. Under this optimized condition, the inhibition rate of mulberry branch bark extract to ACE reached 86% with the half inhibitory concentration （IC50） of 2.19 g/L. The optimized process does not require use of costly instru- ment and is easy to operate.