日本落叶松凋落针叶总黄酮的提取工艺及抗氧化活性研究

Study on extraction technology and antioxidant activity of total flavonoids from Larix kaempferi litter needles

摘要:

为促进日本落叶松废弃物的再利用，本研究以日本落叶松凋落针叶为原料，利用超声辅助浸提法对总黄酮提取工艺进行优化，并对其抗氧化活性进行初步研究.通过三因素三水平响应面分析，得到日本落叶松凋落针叶总黄酮提取的最佳工艺为：乙醇浓度60%、液料比33∶1 mL/g、提取温度80 ℃、超声功率270 W、超声频率40 kHz、提取时间58 min.总黄酮不同萃取相表现出不同程度的体外抗氧化活性，从大到小依次为正丁醇相>水余相>乙酸乙酯相>石油醚相，其中正丁醇对DPPH自由基的半抑制率IC50值为7.438 μg/mL，略弱于维生素C（7.259 μg/mL）；清除ABTS自由基的IC50值为6.425 μg/mL，表现出了比维生素C更高的清除能力.该提取工艺稳定可行，总黄酮得率高，抗氧化活性较好.研究结果表明日本落叶松废弃物有开发成植物源的天然抗氧化剂的潜力.

Abstract:

In order to promote the reuse of Larix kaempferi waste resources， this study used the litter needles of Larix kaempferi as raw materials to optimize the extraction process of total flavonoids by ultrasonic-assisted extraction method, and studied the antioxidant activity of flavonoids. By three-factor three-level response surface analysis, the best extraction process for total flavonoids from Larix kaempferi litter needles was: the ethanol concentration is 60%, the liquid-to-material ratio is 33:1 mL/g, the extraction temperature is 80 ℃, the ultrasonic power is 270 W, the ultrasonic frequency is 40 kHz, and the extraction time is 58 min. Studies on the antioxidant activity of different extraction phases in vitro showed that the antioxidant activity was n-butanol phase>water residue phase>ethyl acetate phase>petroleum ether phase from large to small. The semi-inhibitory rate of n-butanol on DPPH free radical was 7.438 μg/mL, which is slightly weaker than that of vitamin C (7.259 μg/mL); the IC50 value of ABTS radical scavenging was 6.425 μg/mL, showing a higher scavenging capacity than vitamin C. These results showed that the extraction process was stable and feasible, with a high yield of total flavonoids and good antioxidant activity. The research results show that Larix kaempferi waste has the potential to develop into plant-derived natural antioxidants.