菠萝蜜果皮多酚超声微波协同提取工艺优化及抗氧化活性研究

Optimization of ultrasonic-microwave assisted extraction of polyphenols from jackfruit peel and evaluation of its antioxidant activities

采用超声-微波协同提取技术(UMAE)对菠萝蜜果皮中多酚的提取工艺进行优化,并对抗氧化活性进行了评价。以单因素实验为基础,根据Box-Behnken中心组合设计原理,选取乙醇体积分数、料液比、微波功率和微波时间4因素3水平进行响应曲面分析,建立多酚得率的二次多项数学模型,分析各因素的显著性和交互作用,得到多酚提取工艺的最佳条件为:乙醇体积分数70%、料液比1∶40、微波功率75 W、微波时间12 min,多酚得率为7.19 mg/g。在该条件下,超声-微波协同提取方法提取效率优于传统水浴回流法(1.04 mg/g)、微波辅助法(5.23 mg/g)和超声辅助法(5.89 mg/g)。抗氧化活性研究表明,菠萝蜜果皮多酚提取物对DPPH自由基和ABTS自由基均有较强的清除能力,呈量效关系,其EC50值分别为101.39μg/m L和106.60μg/m L,表明多酚是菠萝蜜果皮抗氧化活性的物质基础。

In order to maximize the yield of polyphenols from jackfruit peel,response surface methodology（RSM）was employed to optimize the ultrasonic-microwave assisted extraction（UMAE） conditions,and the antioxidant activities of the polyphenol extracts were evaluated in vitro. On the basis of single-factor experiments,the Box-Behnken center-composite experimental design principle was used to design the experiments and the response surface analysis with 4 factors and 3 levels was adopted. A second order quadratic equation for extraction of polyphenols was created. After analyzed the significance of various factors and their interactions,the optimal extraction conditions for polyphenols from jackfruit peel were determined as follows：70% aqueous ethanol as the extraction solvent,1∶40 as solid-liquid ratio,extraction time 12 min and microwave power 75 W.The extraction yield of polyphenols was determined to be 7.19 mg/g under the optimized extraction conditions,which were above that of traditional hot water extraction,microwave assisted extraction and ultrasonic assisted extraction（1.04 mg/g,5.23mg/g and 5.89 mg/g,respectively）. These results confirmed that UMAE of polyphenols had great potential and efficiency compared with traditonal extraction technologies. Furthermore,the experiments of antioxidant activity showed that polyphenol extracts of jackfruit peel exhibited strong antioxidant activities by the DPPH and ABTS radical scavenging assays,and the EC50 were 101.39 μg/m L and 106.60 μg/m L,respectively.The present study showed that the jackfruit peel were strong radical scavengers and could be considered as a good source of natural antioxidants for medicinal and commercial uses.