摘要
研究辣木叶多酚的超声辅助双水相提取工艺和抗氧化活性,以多酚提取率为评价指标,以硫酸铵用量、正丙醇体积分数、液料比、超声时间和超声温度为自变量,在单因素试验的基础上采用Box-Behnken设计-响应面法(RSM)优化辣木叶多酚的超声波辅助正丙醇-硫酸铵双水相提取工艺;通过抗氧化能力指数(ORAC)和对羟基自由基(OH·)、1,1-二苯基-2-三硝基苯肼自由基(DPPH·)和2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(ABTS·^+)的清除能力评价其抗氧化活性.结果表明,辣木叶多酚超声波辅助双水相提取的最佳工艺参数为:硫酸铵用量0.3 g·mL^-1,正丙醇体积分数78%,液料比52.5∶1(V·m^-1,mL·g^-1),超声时间50 min和超声温度51℃.在此工艺下,辣木叶多酚提取率的预测值和验证试验的值分别为3.17%和3.20%±0.02%,所得回归模型拟合良好.辣木叶多酚提取物的ORAC值为8296±76μmol TE·g^-1,其清除OH·、DPPH·和ABTS·^+的半数清除浓度(IC50)值分别为317.72±12.41μg·mL^-1、6.13±0.24μg·mL^-1和27.63±5.61μg·mL^-1,且清除OH·、DPPH·的效果分别优于或接近维生素C(VC).本研究结果表明,辣木叶多酚是一个具开发潜力的天然抗氧化剂.
Ultrasonic assisted aqueous two-phase extraction was used to obtain polyphenols from Moringa oleif⁃era Lam.leaves and their antioxidant activities were determined.The ultrasonic-assisted propanol-ammonium sulfate aqueous two-phase extraction process was optimized by Box-Behnken design-response surface method(RSM),based on single factor experiment results.Ammonium sulfate dosage,propanol volume fraction,liquidsolid ratio,ultrasonic time and ultrasonic temperature were taken as independent variables.The extraction rate of polyphenols from M.oleifera leaves was taken as the index and its antioxidant activity was evaluated by antiox⁃idant activity index(ORAC)and scavenging capacity of hydroxyl radical(OH·),1,1-diphenyl-2-trinitro⁃phenylhydrazine radical(DPPH·)and 2,2-diazo-bis(3-ethylbenzothiazol-6-sulfonic acid)diammonium radi⁃cal(ABTS·^+).The optimal process parameters were as follows:ammonium sulfate dosage of 0.3 g·mL^-1,propa⁃nol volume fraction of 78%,liquid-solid ratio of 52.5∶1(V·m^-1,mL·g^-1),ultrasonic time of 50 min,ultrason⁃ic temperature of 51℃.Under this process,the predicted value of polyphenol extraction rate from M.oleifera leaves was 3.17%,and the verified value 3.20%±0.02%.The obtained regression model fits well.The ORAC value was 8296±76μmol TE·g^-1.The half scavenging concentration(IC50)values on OH·,DPPH·and ABTS·^+scavenging were 317.72±12.41μg·mL^-1,6.13±0.24μg·mL^-1 and 27.63±5.61μg·mL^-1,respectively.The scav⁃enging effects on OH·and DPPH·were superior to or close to those of vitamin C(VC).The results suggest that polyphenols from M.oleifera leaves are potential natural antioxidants waiting to be developed.
作者
董乐
王芳
李小琴
梁文文
DONG Le;WANG Fang;LI Xiao-qin;LIANG Wen-wen(College of Ocean and Food,Quanzhou Normal University,Quanzhou 362000,China)
出处
《内蒙古民族大学学报（自然科学版）》
2020年第5期387-395,407,共10页
Journal of Inner Mongolia Minzu University：Natural Sciences
基金
福建省引导性项目(2016N0028)
泉州师范学院开放实验项目(20170125)。
