title: Characteristics of compounds in hops using cyclic voltammetry, UV-VIS, FTIR and GC-MS analysis.
abstract: The article presents the antioxidant properties of the extracts of hop EI and EII, by the electrochemical methods on a platinum electrode and comparative analysis of the composition of the extracts of hops using UV-VIS, FTIR and GC-MS methods. The hops extract EI, was obtained from the waste of the hops cone. The hops extract EII, was obtained from the hops cone itself. Hops contain a wide range of polyphenolic compounds with antioxidant properties divided in various chemical classes. Flavonoids and other polyphenolic compounds contained in hops show antioxidant capacity because of the presence of hydroxyl groups in various configurations and numbers within their molecules. The electrochemical properties and antioxidant capacity of hop samples were determined to select the most effective antioxidant. Based on the cyclic and pulse voltammograms, it was observed that hop extract EI contains polyphenols that are oxidised at a less positive potential than extract EII, i.e., it shows better antioxidant capacity. From the analysis of the UV-VIS and FTIR spectra and the GC-MS analysis, it was observed that extract EI contains less phenyl compounds than EII. In addition to flavonoids, EII contains hop acids and chlorophyll. The solutions of hop extracts show very good antioxidant capacities; therefore, they can effectively inhibit or slow negative oxidation reactions and scavenge free radicals and reactive oxygen species (ROS).
authors.affiliation: Technical University of Lodz, Institute of Polymer and Dye Technology, Faculty of Chemistry, ul Stefanowskiego 12/16, 90-924 Lodz, Poland. Electronic address: anna.masek@p.lodz.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Masek
authors.affiliation: Technical University of Lodz, Institute of General and Ecological Chemistry, Faculty of Chemistry, ul Zeromskiego 116, 90-924 Lodz, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Chrzescijanska
authors.affiliation: Technical University of Lodz, Institute of Polymer and Dye Technology, Faculty of Chemistry, ul Stefanowskiego 12/16, 90-924 Lodz, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Kosmalska
authors.affiliation: Technical University of Lodz, Institute of Polymer and Dye Technology, Faculty of Chemistry, ul Stefanowskiego 12/16, 90-924 Lodz, Poland.
authors.forename: Marian
authors.initials: M
authors.lastname: Zaborski
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D004563:Electrochemistry; D005419:Flavonoids / Q000737:chemistry; D005504:Food Analysis / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D027582:Humulus / Q000737:chemistry*; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000737:chemistry; D059808:Polyphenols / Q000737:chemistry; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D010936:Plant Extracts; D059808:Polyphenols
keywords: Antioxidant activity; Electrochemical oxidation; GC–MS method; Hop; UV–VIS and FTIR spectroscopy