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Ieritano C, Haack A, Hopkins WS. Chemical Transformations Can Occur during DMS Separations: Lessons Learned from Beer's Bittering Compounds. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023. [PMID: 37310853 DOI: 10.1021/jasms.3c00040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
While developing a DMS-based separation method for beer's bittering compounds, we observed that the argentinated forms of humulone tautomers (i.e., [Hum + Ag]+) were partially resolvable in a N2 environment seeded with 1.5 mol % of isopropyl alcohol (IPA). Attempting to improve the separation by introducing resolving gas unexpectedly caused the peaks for the cis-keto and trans-keto tautomers of [Hum + Ag]+ to coalesce. To understand why resolution loss occurred, we first confirmed that each of the tautomeric forms (i.e., dienol, cis-keto, and trans-keto) responsible for the three peaks in the [Hum + Ag]+ ionogram were assigned to the correct species by employing collision-induced dissociation, UV photodissociation spectroscopy, and hydrogen-deuterium exchange (HDX). The observation of HDX indicated that proton transfer was stimulated by dynamic clustering processes between IPA and [Hum + Ag]+ during DMS transit. Because IPA accretion preferentially occurs at Ag+, which can form pseudocovalent bonds with a suitable electron donor, solvent clustering also facilitated the formation of exceptionally stable microsolvated ions. The exceptional stability of these microsolvated configurations disproportionately impacted the compensation voltage (CV) required to elute each tautomer when the temperature within the DMS cell was varied. The disparity in CV response caused the peaks for the cis- and trans-keto species to merge when a temperature gradient was induced by the resolving gas. Moreover, simulations showed that microsolvation with IPA mediates dienol to trans-keto tautomerization during DMS transit, which, to the best of our knowledge, is the first observation of keto/enol tautomerization occurring within an ion-mobility device.
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Affiliation(s)
- Christian Ieritano
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
- Watermine Innovation, Waterloo, Ontario N0B 2T0, Canada
| | - Alexander Haack
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - W Scott Hopkins
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
- Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
- Watermine Innovation, Waterloo, Ontario N0B 2T0, Canada
- Centre for Eye and Vision Research, 17 W Hong Kong Science Park, Shatin, New Territories 999077, Hong Kong
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2
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Tutun E, Tekin V, Yasakcı V, Aras Ö, Ünak P. Synthesis and morphological studies of Tc-99m-labeled lupulone-conjugated Fe 3O 4@TiO 2 nanocomposite, and in vitro cytotoxicity activity on prostate cancer cell lines. Appl Organomet Chem 2021; 35:e6435. [PMID: 36582207 PMCID: PMC9797211 DOI: 10.1002/aoc.6435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The purpose of this study was to develop a multifunctional theranostic probe for imaging (magnetic resonance imaging [MRI] and single-photon emission computed tomography [SPECT]) and therapy (photodynamic therapy). For this purpose, Tc-99m-labeled lupulone-conjugated Fe3O4@TiO2 nanocomposites (99mTc-DTPA-Fe3O4@TiO2-HLP and 99mTc-DTPA-Fe3O4@TiO2-ALP nanocomposites) were synthesized. The average diameter of the nanocomposites was 171 ± 20 nm as seen on transmission electron microscopy images. Fe3O4@TiO2 nanocomposites exhibited fluorescence spectra at an emission wavelength of 314 nm. Lupulone-conjugated Fe3O4@TiO2 nanocomposites were spherical-shaped with a suitable dispersion and without visible aggregation, and their radiolabeling yields were over 85%. Healthy (RWPE-1 normal human prostate epithelial cell line) and cancer prostate cell lines (PC-3 human prostate cancer cell line) were used to determine the in vitro biological behavior of the nanocomposites. The PC-3 cells treated with lupulone-conjugated Fe3O4@TiO2 nanocomposites showed a lower cell viability compared with RWPE-1 cells treated with lupulone-conjugated Fe3O4@TiO2 nanocomposites. Lupulone-modified Fe3O4@TiO2 nanocomposites may serve in the future as a multifunctional probe for positron emission tomography (PET)/MRI, photodynamic therapy, and hyperthermia therapy of cancer.
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Affiliation(s)
- Elif Tutun
- Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Izmir, Turkey
| | - Volkan Tekin
- Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Izmir, Turkey
| | - Volkan Yasakcı
- Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Izmir, Turkey
| | - Ömer Aras
- Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Perihan Ünak
- Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Izmir, Turkey
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Yang G, Nie C, Zhang H, Sun S, Wang X, Zhang J, Xu H, Liu J. The tolerance of brewing-related microorganisms to isomerized hop products and the effect on beer stability and quality. Eur Food Res Technol 2020. [DOI: 10.1007/s00217-020-03644-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Duarte LM, Amorim TL, Adriano LHC, Oliveira MAL. Baseline separation of α and β‐acids homologues and isomers in hop (
Humulus lupulus L
.) by CD‐MEKC‐UV. Electrophoresis 2019; 40:1779-1786. [DOI: 10.1002/elps.201900101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/06/2019] [Accepted: 05/11/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Lucas M. Duarte
- GQAQ: Grupo de Química Analítica e Quimiometria, Departament of ChemistryUniversidade Federal de Juiz de Fora Juiz de Fora Brazil
| | - Tatiane L. Amorim
- GQAQ: Grupo de Química Analítica e Quimiometria, Departament of ChemistryUniversidade Federal de Juiz de Fora Juiz de Fora Brazil
| | - Luiz H. C. Adriano
- GQAQ: Grupo de Química Analítica e Quimiometria, Departament of ChemistryUniversidade Federal de Juiz de Fora Juiz de Fora Brazil
| | - Marcone A. L. Oliveira
- GQAQ: Grupo de Química Analítica e Quimiometria, Departament of ChemistryUniversidade Federal de Juiz de Fora Juiz de Fora Brazil
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5
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Liu Y, Lu N, Tang J. Synthesis, characterization, crystal structure, and antioxidant activity of hexahydro-β-acids. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2018.08.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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6
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Chai K, Xu Z, Zheng L, Zhou L, Tong Z, Ji H. Facile separation of cinnamyl acetate and cinnamaldehyde based on host-guest complexation with β-cyclodextrin. FLAVOUR FRAG J 2018. [DOI: 10.1002/ffj.3443] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Kungang Chai
- School of Light Industry and Food Engineering; Guangxi University; Nanning China
- School of Chemistry and Chemical Engineering, Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology; Guangxi University; Nanning China
| | - Zhijun Xu
- School of Light Industry and Food Engineering; Guangxi University; Nanning China
| | - Lu Zheng
- School of Light Industry and Food Engineering; Guangxi University; Nanning China
| | - Liqin Zhou
- School of Chemistry and Chemical Engineering, Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology; Guangxi University; Nanning China
| | - Zhangfa Tong
- School of Chemistry and Chemical Engineering, Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology; Guangxi University; Nanning China
| | - Hongbing Ji
- School of Chemistry and Chemical Engineering, Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology; Guangxi University; Nanning China
- Fine Chemical Industry Research Institute; School of Chemistry; Sun Yat-sen University; Guangzhou China
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Schurr BC, Hahne H, Kuster B, Behr J, Vogel RF. Molecular mechanisms behind the antimicrobial activity of hop iso-α-acids in Lactobacillus brevis. Food Microbiol 2014; 46:553-563. [PMID: 25475328 DOI: 10.1016/j.fm.2014.09.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 09/24/2014] [Accepted: 09/28/2014] [Indexed: 11/30/2022]
Abstract
The main bittering component in beer, hop iso-α-acids, have been characterised as weak acids, which act as ionophores impairing microbial cells' function under acidic conditions as present in beer. Besides medium pH, divalent cations play a central role regarding the efficacy of the antimicrobial effect. The iso-α-acids' non-bitter derivatives humulinic acids can be found in isomerised hop extracts and can be generated during hop storage. Therefore, they have been under investigation concerning their influence on beer sensory properties. This study sketches the molecular mechanism behind iso-α-acids' antimicrobial activity in Lactobacillus (L.) brevis regarding their ionophore activity versus the dependence of the inhibitory potential on manganese binding, and suggests humulinic acids as novel tasteless food preservatives. We designed and synthesised chemically modified iso-α-acids to enhance the basic understanding of the molecular mechanism of antimicrobial iso-α-acids. It could be observed that a manganese-binding dependent transmembrane redox reaction (oxidative stress) plays a crucial role in inhibition. Privation of an acidic hydroxyl group neither erased ionophore activity, nor did it entirely abolish antimicrobial activity. Humulinic acids proved to be highly inhibitory, even outperforming iso-α-acids.
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Affiliation(s)
- Benjamin C Schurr
- Technische Universität München, Lehrstuhl für Technische Mikrobiologie, 85354 Freising, Germany
| | - Hannes Hahne
- Chair for Proteomics and Bioanalytics, Technische Universität München, Freising, Germany
| | - Bernhard Kuster
- Chair for Proteomics and Bioanalytics, Technische Universität München, Freising, Germany; Center for Integrated Protein Science Munich, Germany
| | - Jürgen Behr
- Technische Universität München, Lehrstuhl für Technische Mikrobiologie, 85354 Freising, Germany.
| | - Rudi F Vogel
- Technische Universität München, Lehrstuhl für Technische Mikrobiologie, 85354 Freising, Germany
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Steenackers B, De Cooman L, De Vos D. Chemical transformations of characteristic hop secondary metabolites in relation to beer properties and the brewing process: a review. Food Chem 2014; 172:742-56. [PMID: 25442616 DOI: 10.1016/j.foodchem.2014.09.139] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 08/20/2014] [Accepted: 09/24/2014] [Indexed: 10/24/2022]
Abstract
The annual production of hops (Humulus lupulus L.) exceeds 100,000 mt and is almost exclusively consumed by the brewing industry. The value of hops is attributed to their characteristic secondary metabolites; these metabolites are precursors which are transformed during the brewing process into important bittering, aromatising and preservative components with rather low efficiency. By selectively transforming these components off-line, both their utilisation efficiency and functionality can be significantly improved. Therefore, the chemical transformations of these secondary metabolites will be considered with special attention to recent advances in the field. The considered components are the hop alpha-acids, hop beta-acids and xanthohumol, which are components unique to hops, and alpha-humulene and beta-caryophyllene, sesquiterpenes which are highly characteristic of hops.
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Affiliation(s)
- Bart Steenackers
- Centre for Surface Science and Catalysis, KU Leuven, Kasteelpark Arenberg 23, 3001 Leuven, Belgium
| | - Luc De Cooman
- Laboratory for Enzyme and Brewing Technology, KaHo St.-Lieven, Gebroeders Desmetstraat 1, 9000 Gent, Belgium
| | - Dirk De Vos
- Centre for Surface Science and Catalysis, KU Leuven, Kasteelpark Arenberg 23, 3001 Leuven, Belgium.
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Chai K, Ji H. Inclusive separation of acetophenone from petrochemical by-product with 1-phenylethanol via noncovalent interactions. AIChE J 2014. [DOI: 10.1002/aic.14474] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Kungang Chai
- School of Chemistry and Chemical Engineering, The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province; Sun Yat-sen University; Guangzhou 510275 P.R. China
| | - Hongbing Ji
- School of Chemistry and Chemical Engineering, The Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province; Sun Yat-sen University; Guangzhou 510275 P.R. China
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Masek A, Chrzescijanska E, Kosmalska A, Zaborski M. Characteristics of compounds in hops using cyclic voltammetry, UV-VIS, FTIR and GC-MS analysis. Food Chem 2014; 156:353-61. [PMID: 24629980 DOI: 10.1016/j.foodchem.2014.02.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 12/18/2013] [Accepted: 02/03/2014] [Indexed: 02/03/2023]
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).
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Affiliation(s)
- Anna Masek
- Technical University of Lodz, Institute of Polymer and Dye Technology, Faculty of Chemistry, ul Stefanowskiego 12/16, 90-924 Lodz, Poland.
| | - Ewa Chrzescijanska
- Technical University of Lodz, Institute of General and Ecological Chemistry, Faculty of Chemistry, ul Zeromskiego 116, 90-924 Lodz, Poland
| | - Anna Kosmalska
- Technical University of Lodz, Institute of Polymer and Dye Technology, Faculty of Chemistry, ul Stefanowskiego 12/16, 90-924 Lodz, Poland
| | - Marian Zaborski
- Technical University of Lodz, Institute of Polymer and Dye Technology, Faculty of Chemistry, ul Stefanowskiego 12/16, 90-924 Lodz, Poland
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Kappler S, Krahl M, Geissinger C, Becker T, Krottenthaler M. Degradation of Iso-α-Acids During Wort Boiling. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.2010.tb00783.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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12
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De Clippeleer J, De Rouck G, De Cooman L, Aerts G. Influence of the Hopping Technology on the Storage-induced Appearance of Staling Aldehydes in Beer. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.2010.tb00789.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Dahlberg CJ, Harris G, Urban J, Tripp ML, Bland JS, Carroll BJ. Isolation of bitter acids from hops (Humulus lupulus L.) using countercurrent chromatography. J Sep Sci 2012; 35:1183-9. [PMID: 22689494 DOI: 10.1002/jssc.201101109] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Commercially available hops (Humulus lupulus L.) bitter acid extracts contain a mixture of three major congeners (co-, n-, and ad-) in addition to cis/trans diastereomers for each congener. Individual isomerized α-acids were obtained by the consecutive application of two separate countercurrent chromatography methods. First, individual isomerized α-acid congeners as a mixture of cis/trans diastereomers were obtained using a solvent system consisting of hexane and aqueous buffer. The second purification, capable of separating cis/trans diastereomers, was accomplished using a quaternary solvent system; an alternative procedure using β-cyclodextrin followed by countercurrent chromatography was also investigated. The NaBH(4) reduction of the purified isomerized α-acid compounds followed by countercurrent chromatography purification resulted in individual ρ iso α-acids (>95%). Similarly, catalytic hydrogenation of the purified isomerized α-acid compounds followed by countercurrent chromatography purification produced individual tetrahydro isomerized α-acids (>95%). Reported herein is a widely applicable approach that focuses on three critical variables--solvent system composition, pH, and buffer-to-sample ratio--that enable the efficient purification of individual bitter acids (≥95%) from commercially available hops extracts.
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Caballero I, Blanco CA, Porras M. Iso-α-acids, bitterness and loss of beer quality during storage. Trends Food Sci Technol 2012. [DOI: 10.1016/j.tifs.2012.01.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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15
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de Almeida NEC, Homem-de-Mello P, De Keukeleire D, Cardoso DR. Reactivity of beer bitter acids toward the 1-hydroxyethyl radical as probed by spin-trapping electron paramagnetic resonance (EPR) and electrospray ionization-tandem mass spectrometry (ESI-MS/MS). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:4183-4191. [PMID: 21401101 DOI: 10.1021/jf104797d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The iso-α-acids or isohumulones are the major contributors to the bitter taste of beer, and it is well-recognized that they are degraded during beer aging. In particular, the trans-isohumulones seem to be less stable than the cis-isohumulones. The major radical identified in beer is the 1-hydroxyethyl radical; however, the reactivity between this radical and the isohumulones has not been reported until now. Therefore, we studied the reactivity of isohumulones toward the 1-hydroxyethyl radical through a competitive kinetic approach. It was observed that both cis- and trans-isohumulones and dihydroisohumulones are decomposed in the presence of 1-hydroxyethyl radicals, while the reactivities are comparable. On the other hand, the tetrahydroisohumulones did not react with 1-hydroxyethyl radicals. The apparent second-order rate constants for the reactions between the 1-hydroxyethyl radical and these compounds were determined by electron paramagnetic resonance (EPR) spectroscopy and electrospray ionization-tandem mass spectrometry [ESI(+)-MS/MS]. It follows that degradation of beer bitter acids is highly influenced by the presence of 1-hydroxyethyl radicals. The reaction products were detected by liquid chromatography-electrospray ionization-ion trap-tandem mass spectrometry (LC-ESI-IT-MS/MS), and the formation of oxidized derivatives of the isohumulones was confirmed. These data help to understand the mechanism of beer degradation upon aging.
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Affiliation(s)
- Natália E C de Almeida
- Instituto de Química de São Carlos (IQSC), Universidade de São Paulo, São Carlos, São Paulo, Brazil
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