title: Optimization of microwave-assisted extraction (MAE) of coriander phenolic antioxidants - response surface methodology approach.
abstract: BACKGROUND
  Microwave-assisted extraction (MAE) of polyphenols from coriander seeds was optimized by simultaneous maximization of total phenolic (TP) and total flavonoid (TF) yields, as well as maximized antioxidant activity determined by 1,1-diphenyl-2-picrylhydrazyl and reducing power assays. Box-Behnken experimental design with response surface methodology (RSM) was used for optimization of MAE. Extraction time (X1 , 15-35 min), ethanol concentration (X2 , 50-90% w/w) and irradiation power (X3 , 400-800 W) were investigated as independent variables. Experimentally obtained values of investigated responses were fitted to a second-order polynomial model, and multiple regression analysis and analysis of variance were used to determine fitness of the model and optimal conditions.
  
  
  RESULTS
  The optimal MAE conditions for simultaneous maximization of polyphenol yield and increased antioxidant activity were an extraction time of 19 min, an ethanol concentration of 63% and an irradiation power of 570 W, while predicted values of TP, TF, IC50 and EC50 at optimal MAE conditions were 311.23 mg gallic acid equivalent per 100 g dry weight (DW), 213.66 mg catechin equivalent per 100 g DW, 0.0315 mg mL(-1) and 0.1311 mg mL(-1) respectively.
  
  
  CONCLUSIONS
  RSM was successfully used for multi-response optimization of coriander seed polyphenols. Comparison of optimized MAE with conventional extraction techniques confirmed that MAE provides significantly higher polyphenol yields and extracts with increased antioxidant activity. © 2016 Society of Chemical Industry.
authors.affiliation: Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000, Novi Sad, Serbia.
authors.forename: Zoran
authors.initials: Z
authors.lastname: Zeković
authors.affiliation: Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000, Novi Sad, Serbia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Vladić
authors.affiliation: Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000, Novi Sad, Serbia.
authors.forename: Senka
authors.initials: S
authors.lastname: Vidović
authors.affiliation: Institute of Field and Vegetable Crops, Maksima Gorkog 30, 21000, Novi Sad, Serbia.
authors.forename: Dušan
authors.initials: D
authors.lastname: Adamović
authors.affiliation: Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000, Novi Sad, Serbia.
authors.forename: Branimir
authors.initials: B
authors.lastname: Pavlić
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D028526:Coriandrum / Q000737:chemistry* / Q000528:radiation effects; D019587:Dietary Supplements / Q000032:analysis; D000431:Ethanol / Q000737:chemistry; D005419:Flavonoids / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D005514:Food Irradiation; D007700:Kinetics; D008872:Microwaves; D008956:Models, Chemical; D010636:Phenols / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification*; D012639:Seeds / Q000737:chemistry* / Q000528:radiation effects; D055771:Serbia; D012997:Solvents / Q000737:chemistry; D013223:Statistics as Topic
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D012997:Solvents; D000431:Ethanol
keywords: antioxidant activity; coriander seeds; microwave-assisted extraction (MAE); polyphenols; response surface methodology (RSM)