紫苏叶花青素提取工艺及其活性研究

Study on Extraction Process and Activity of Anthocyanin from Perilla frutescens Leaves

为提高紫苏的综合利用率,探究紫苏叶中花青素的最佳提取工艺条件并对其抗氧化和抑菌活性进行研究。结果发现,乙醇提取法的最佳条件为2.5%HCl-60%乙醇60℃提取2.5 h,花青素得率为4.003 mg/100 g;超声波辅助提取法的最佳提取工艺为超声功率450 W,超声时间20 min,料液比1∶40(g/m L),超声温度为40℃,花青素得率为5.489 mg/100 g。超声波辅助提取法较乙醇提取法,花青素得率提高0.37倍,提取时间缩短了86.67%,提取温度降低,降低成本。通过总抗氧化能力(ferric reducing antioxidant potential,FRAP)测定发现紫苏叶花青素具有较强的铁离子还原氧化能力,此外紫苏叶花青素对DPPH·、·OH、O2-·有特定的清除能力,因此花青素具有一定的抗氧化能力。不同浓度紫苏叶花青素对不同的菌株均有一定的抑制性能,对大肠杆菌有较好的抑制作用,其最小抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimum bactericidal concentration,MBC)分别为1.25 mg/m L和2.5 mg/m L,对腐败希瓦氏菌抑制作用不明显。

To improve the comprehensive utilization of Perilla frutescens,this paper had explored the best extraction process of anthocyanin from leaves of Perilla frutescens,at the same time,this paper also studied on the antioxidant and antibacterial activities of anthocyanin from leaves of Perilla frutescens. The results showed that the optimized extraction conditions by the method of ethanol extraction were as follows：extraction with 2.5 %HCl-60 % aqucous ethanol solution at 60 ℃ for 2.5 h,the yield of anthocyanin was 4.003 mg/100 g under these conditions. In addition,the optimum extraction conditions by the method of ultrasound-assisted extraction were obtained as follows：ultrasonic power 450 W,ultrasonic time 20 min,ratio of liquid to solid 1 ∶ 40（g/m L）and ultrasonic temperature 40 ℃,the yield of anthocyanin was 5.489 mg/100 g under these conditions. Compared with the ethanol extraction method,the extraction yield of anthocyanins by the method of ultrasound-assisted extraction increased by 0.37 times and the extraction time shortened by 86.67 %,the extraction temperature decreased and the cost reduced. Through the ferric reducing antioxidant potential（FPAR）,it was found that anthocyanins from leaves of Perilla frutescens had a strong ability of reduction and oxidation of iron ions,specific scavenging ability on DPPH·,·OH and O2-·,so anthocyanin from leaves of Perilla frutescens had a certain antioxidant capacity. Different concentration of anthocyanin from leaves of Perilla frutescens on different strains had a certain inhibitory effect,which could restrain in Escherichia coli＇s growth avalibily,the minimum inhibitory concentration（MIC）and minimum bactericidal concentration（MBC）were 1.25 mg/m L and 2.5 mg/m L,and had little influence on the antimicrobial effect on Shewanella putrefaciens.