本文以莲子加工副产物-莲子皮渣为实验材料，在单因素实验的基础上，以总酚、总原花色素、DPPH·+清除能力为响应值，通过响应面设计优化莲子皮渣活性成分超声辅助提取条件，建立二次响应面回归模型，模型均显著且拟合性好。最优提取工艺为：丙酮浓度70%，料液比1:25.5 g /mL，提取时间1.6 h，提取温度50 ℃。该提取条件下，里叶白莲莲子皮渣提取物总酚、总原花色素、DPPH·+清除能力分别为194.54±3.63 mg GAE/g DW，243.15±2.88 mg CE/g DW，238.53 ± 3.07 mg AAE/g DW，与预测值相符，证明实验建立的响应面模型可用于莲子皮渣中总酚、总原花色素、DPPH·+清除能力实验结果预测。对不同品种莲子皮渣植物化学素含量及体外抗氧化活性进行测定，发现莲子皮渣均富含多酚、类黄酮、原花色素、三萜等生物活性物质，且具有较高体外抗氧化活性。研究表明莲子皮渣富含生物活性成分，具有开发利用的巨大潜在价值。

Lotus seed processing by-product-lotus seed epicarp residue was collected as experimental materials. Based on the results of single factor experiment, response surface methodology (RSM) was used to optimize the ultrasonic-assisted extraction of bioactive compounds from lotus seed epicarp residue, and total phenolic content (TPC), total proanthocyanidin content and DPPH·+ scavenging capacity were set as response values. Experimental data were fitted to three quadratic polynomial models and the regression equations were significant with good fitting degree. The optimal extraction conditions were as follows: Acetone concentration of 70%, liquid to solid ratio of 1:25.5 g/ mL, extraction temperature as 50 ℃ and sonication time as1.6 hour. Under these conditions, the practical values of responses were 194.54±3.63 mg GAE/g DW, 243.15±2.88 mg CE/g DW, 238.53±3.07 mg AAE/g DW, respectively, which were consistent with the predicted values. So the established models could accurately predict the results of total phenolic content, total proanthocyanidin content and DPPH·+ scavenging capacity in lotus seed epicarp residue. We determined the phytochemical content and in vitro antioxidant activities of diverse lotus seed epicarp residue and found that they are rich in bioactive compounds including polyphenols, flavonoids, proanthocyanidins, triterpenes, and with high antioxidant activity. The study suggested that lotus seed epicarp residue contains high amount of bioactive chemicals and is of great potential for research and development.

浙江省重点研发项目（2018C02049）；杭州市农业科研攻关专项（20191203B31）