油莎草总黄酮的动态高压微射流辅助提取及其在曲奇饼干中的应用

Dynamic High-pressure Microfluidization-assisted Method for Extraction of Total Flavonoids from Cyperus esculentus L. Leaves and Application in Cookies

以总黄酮得率及DPPH·清除率为考察指标,通过单因素及正交试验得到动态高压微射流辅助提取油莎草总黄酮的最优提取工艺,采用紫外与红外光谱和高效液相色谱-质谱联用法(LC-MS)分析了动态高压微射流辅助提取对油莎草总黄酮结构和组成的影响,同时以过氧化值、酸价为指标,考察了油莎草总黄酮对曲奇饼干贮藏性的影响。结果表明,最优提取工艺为:微射流处理压力120 MPa,提取温度80℃,乙醇浓度80%,提取时间90 min,总黄酮提取得率为1.46%,对DPPH·自由基的清除能力IC50值为0.17±0.02mg/mL,动态高压微射流辅助提取提高了总黄酮的得率和抗氧化性,LC-MS分析表明动态高压微射流技术未改变总黄酮的组成,但使有些组分的比例发生了变化。通过测定曲奇饼干的过氧化值和酸价值得出油莎草总黄酮可以作为天然抗氧化剂用于制作曲奇饼干。

The optimum conditions for extraction of flavonoids from Cyperus esculentus L.（CE L.） leaves by dynamic high-pressure microfluidization-assisted method（DHPM） was determined through single factor and orthogonal experiments. The yield of flavonoids and the 2,2-diphenyl-1-picrylhydrazyl（DPPH） radical scavenging rate were used as indices. The effect of DHPM on the structure and composition of total flavonoids from CE L. leaves was preliminarily analyzed by ultraviolet-visible and infrared spectral analyses and liquid chromatography–mass spectrometry（LC-MS）. At the same time, peroxide value（POV） and acid value（AV） were used as indicators to investigate the effect of total flavonoids from CE L. leaves on the storability of cookies. The results showed the following conditions of DHPM as optimum： microfluidization pressure=120 MPa; extraction temperature=80 ℃; ethanol concentration=80%; extraction time=90 min. Under these optimal extraction conditions, the yield of flavonoids was 1.46% and the half-maximal inhibitory concentration（IC50） value for DPPH scavenging activity was 0.17±0.02 mg/mL. The DHPM-assisted extraction enhanced the yield and antioxidant activities of total flavonoids from CE L. leaves. The results of LC-MS analysis indicated that the treatment of DHPM did not change the composition of total flavonoids from CE L. leaves; however, the ratio of some constituents were altered. The results of POV and AV showed that total flavonoids from CE L. leaves could serve as natural antioxidants for cookie production.