title: Antioxidant and enzyme inhibitory activities of blueberry anthocyanins prepared using different solvents.
abstract: We compared the biological activities of anthocyanins prepared from whole blueberries or pomace and extracted with acetone, ethanol, and methanol. Crude Amberlite extracts (CAE) and rehydrated powders of freeze-dried anthocyanins were used. Ethanolic CAE yielded the highest total monomeric anthocyanin content [TMAC] (160 ppm), ferric reducing antioxidant power [FRAP] (3.4 mM Fe(2+)), total phenolics content [TPC] (382 ppm gallic acid equivalents [GAE]), and α-amylase inhibitory activity (36.8%). The rehydrated powder from acetonic extract gave the greatest FRAP (5.19) and TPC (422.7). α-Amylase (26.1%) and α-glucosidase (91.5%) inhibitory activities were also sustained. Methanolic CAE yielded values intermediate between ethanolic and acetonic extracts. Comparison of mass spectra between Amberlite extracts and rehydrated preparations revealed putative degradation and dimerization products in the rehydrated powders, which could account for loss in biological activities for rehydrated methanolic and ethanolic powders. Results of this study provide useful information in optimizing anthocyanin preparation methods for improved biological activity.
authors.affiliation: Department of Food Science and Technology, College of Agricultural and Environmental Sciences, The University of Georgia, Athens, Georgia 30602-2610, United States.
authors.forename: Floirendo P
authors.initials: FP
authors.lastname: Flores
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Singh
authors.forename: William L
authors.initials: WL
authors.lastname: Kerr
authors.forename: Ronald B
authors.initials: RB
authors.lastname: Pegg
authors.forename: Fanbin
authors.initials: F
authors.lastname: Kong
mesh_terms: D000096:Acetone / Q000737:chemistry; D000872:Anthocyanins / Q000737:chemistry*; D000975:Antioxidants / Q000737:chemistry*; D029798:Blueberry Plants / Q000737:chemistry*; D003124:Colorimetry; D000431:Ethanol / Q000737:chemistry; D005511:Food Handling / Q000379:methods*; D005612:Freeze Drying; D065089:Glycoside Hydrolase Inhibitors; D000432:Methanol / Q000737:chemistry; D010636:Phenols / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D000516:alpha-Amylases / Q000037:antagonists & inhibitors / Q000737:chemistry; D000520:alpha-Glucosidases / Q000737:chemistry
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D065089:Glycoside Hydrolase Inhibitors; D010636:Phenols; D010936:Plant Extracts; D012997:Solvents; D000096:Acetone; D000431:Ethanol; D000516:alpha-Amylases; D000520:alpha-Glucosidases; D000432:Methanol