化橘红黄酮的高压脉冲电场提取及抗氧化活性检测

Pulsed electric field extraction of flavonoids from Exocarpium Citri grandis and its antioxidant activity detection

采用单因素试验考察脉冲次数、料液比、电场强度对高压脉冲电场(PEF)辅助处理提取水性介质中化橘红黄酮得率的影响,通过响应面分析法优化化橘红黄酮的PEF提取工艺;利用乙酸乙酯萃取和AB-8大孔树脂吸附方法纯化提取的化橘红黄酮;采用1,1-二苯基-2-三硝基苯肼(DPPH)法、2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸(ABTS)法和铁离子还原测定(FRAP)法对化橘红黄酮进行体外抗氧化活性研究。结果表明:高压脉冲电场提取化橘红黄酮的最优工艺为脉冲次数250、电场强度7.8 kV/cm和料(W,g)液(V,mL)比1∶70,此时黄酮得率为30.34 mg/g;大孔树脂吸附、乙酸乙酯萃取的黄酮质量分数分别为51.20%、20.90%,大孔树脂吸附的纯化效果更好;粗提取物、大孔树脂吸附、乙酸乙酯萃取的化橘红黄酮的IC50在DPPH法中分别为428.16、112.43、256.64μg/m L,ABTS法中分别为50.57、24.99、23.59μg/m L;粗提取物、大孔树脂吸附、乙酸乙酯萃取的化橘红黄酮的抗坏血酸效价在DPPH法中分别为1268.22、4829.67、2115.80 mg/(100 g),ABTS法中分别为31797.51、64345.74、68164.48 mg/(100 g);大孔树脂吸附、乙酸乙酯萃取、粗提取物的化橘红黄酮的FRAP值依次降低,其结果与DPPH法测定的抗氧化能力一致。

In this study,single-factor experiments were used to explore the effects of pulse number,material-to-liquid ratio,and field strength on the yield of flavonoids extracted from Exocarpium Citri grandis in aqueous medium with high-voltage pulsed electric field auxiliary extraction technology and the optimum extraction conditions were sorted out by a response surface methodology.The flavonoids were purified by ethyl acetate extraction and AB-8 macroporous resin adsorption method.Meanwhile,the anti-oxidant activity in vitro was studied through 1,1-diphenyl-2-trinitrophenylhydrazine(DPPH)method,2,2’-diazo-bis-3-ethylbenzothiazoline-6-sulfonic acid(ABTS)method and iron ion reduction assay(FRAP)method.The result showed that the optimal extraction process were the number of pulses 250 times,electric field intensity 7.8 kV/cm,and the material-liquid ratio 1∶70.With this optimal condition,the yield reached up to 30.34 mg/g.The mass fractions of flavonoids purified by macroporous resin adsorption and ethyl acetate extraction were 51.20%and 20.90%respectively showing that the macroporous resin adsorption was superior.Their IC50 in DPPH method were 428.16,112.43,256.64μg/mL,and that in ABTS method were severally 31797.51,64345.74,68164.48 mg/(100 g).The FRAP value of macroporous resin adsorption,ethyl acetate extraction,and crude extract of flavonoids decreased sequentially which were consistent with the antioxidant capacity determined by the DPPH method.