基于循环超声提取枇杷三萜酸工艺优化及其抗氧化性分析

采用响应面法优化循环超声提取枇杷果肉中的三萜酸的工艺条件，在单因素基础上，选择液料比、乙醇浓度、循环转速、超声时间为影响因素，以三萜酸提取量为指标进行响应面分析，并研究三萜酸提取物的抗氧化活性。结果表明，最佳提取工艺参数为液料比15.5∶1(mL/g)、乙醇浓度70.0%、循环转速811 r/min、超声时间43.5 min，在该条件下三萜酸提取量为(1.789±0.080)mg/g；在三萜酸提取物浓度为0.48 mg/mL时，对ABTS⁺自由基、DPPH自由基、·OH、·O₂^-的清除率分别达到60.11%、77.86%、52.76%、45.34%。对4种自由基的半抑制浓度(IC₅₀)分别为0.148、0.102、0.382、0.510 mg/mL。

Optimization of Extraction of Triterpenic Acids from Loquat by Circulating Ultrasound and Its Antioxidant Activities

Response surface method was employed to optimize the process conditions for extracting triterpenic acids from loquat by circulating ultrasound. Based on the results of single-factor tests，four factors including liquid-solid ratio，ethanol concentration，circulation speed and extraction time were identified as main variables that affected extraction yield，and the amount of extracted triterpenic acids was used as the index for the response surface analysis. Besides，the antioxidant activities of the extracted triterpenic acids were studied. The results showed that the optimal extraction parameters were as follows：liquid-solid ratio of 15.5∶1（mL/g），ethanol concentration of 70.0%，circulation speed of 811 r/min and ultrasonic time of 43.5 min. Under these conditions，the extraction yield of triterpenic acids was（1.789±0.080）mg/g. When the triterpenic acid extract concentration was 0.48 mg/mL，the scavenging rates for ABTS+·，DPPH·，·OH and ·O2- were 60.11%，77.86%，52.76% and 45.34%，respectively. The half maximal inhibitory concentration（IC50）of the four free radicals were 0.148，0.102，0.382 mg/mL and 0.510 mg/mL，respectively.