超声波辅助提取石榴根皮总黄酮及其抑制亚硝化反应活性

探讨了超声波辅助提取石榴根皮总黄酮的工艺条件,以乙醇体积分数、料液比、超声功率和超声时间为影响因素,总黄酮得率为考察指标,在单因素实验基础上,采用Box-Behnken Design(BBD)实验设计优化最佳提取工艺条件,并测定石榴根皮总黄酮对亚硝酸盐的清除能力和对亚硝胺合成的抑制能力。结果表明:当乙醇体积分数63%,料液比1:22 g/mL,超声功率270 W和超声时间34 min时,石榴根皮总黄酮得率为2.81%,与模型预测值接近。石榴根皮总黄酮具有较强的清除亚硝酸盐能力和抑制亚硝胺合成能力,质量浓度为3.6 μg/mL时,对亚硝酸盐的最大清除率为64.5%,清除作用的IC₅₀=2.408 μg/mL,对亚硝胺合成的最大阻断率为71.9%,阻断作用的IC₅₀=2.345 μg/mL。在质量浓度0.12~3.6 μg/mL范围内,石榴根皮总黄酮与对亚硝酸盐清除作用和抑制亚硝酸胺合成作用之间均呈一定的正相关关系。该方法可为石榴根皮总黄酮的提取及应用提供一定的科学依据。

Optimization of ultrasonic-assisted extraction of total flavonoids from pomegranate root bark and thear nitrosation inhibition activity

The ultrasonic-assisted extraction conditions of total flavonoids from pomegranate root bark were studied. Single factor test and Box-Behnken experimental design were used to optimize the extraction process employing total flavonoids yield as the response,and ethanol concentration,solid/liquid ratio,ultrasonic power and ultrasonic time were used as independent variables,and the nitrite scavenging activity and nitrosamine synthesis inhibiting activity were tested. Results showed that under the following conditions:Ethanol concentration of 63%,solid/liquid ratio of 1∶22 g/mL,ultrasonic power of 270 W and ultrasonic time of 34 min,the yield of total flavonoids was 2.81%,close to predicted value. The total flavonoids from pomegranate root bark had a strong nitrite scavenging activity and nitrosamine synthesis inhibiting activity. At the concentration of 3.6 μg/mL,the total flavonoids exhibited a maximum sodium nitrite scavenging rate of 64.5% and the effect of IC₅₀=2.408 μg/mL.At the same time,the total flavonoids exhibited a maximum nitrosamine synthesis inhibiting rate of 71.9% at the effect of IC₅₀=2.345 μg/mL. There was a dose-response relationship between the total flavonoids from pomegranate root bark and the nitrite scavenging activity and nitrosamine synthesis inhibiting activity in the range of 0.12~3.6 μg/mL of concentration. This method could provide a scientific basis for the extraction and application of total flavonoids from pomegranate root bark.