Potential impact of medium characteristics on the isomerisation of hop α-acids in wort and buffer model systems

Jaskula, Barbara; Aerts, Guido; Cooman, Luc De

doi:10.1016/j.foodchem.2010.05.090

Cited by 18 publications

(14 citation statements)

References 21 publications

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“…A maximum isomerization yield of 20.32% was achieved after 35 min of process using HFC extracts. This result could be further improved, as suggested by Jaskula et al [32], which studied the effect of optimizing pH, ionic strength, wort gravity, hopping rate, and metal ion catalysts on isomerization performances.…”

Section: Resultsmentioning

confidence: 94%

Using Hydrofluorocarbon Extracts of Hop in a Pilot Scale Brewing Process

et al. 2022

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In recent years, the use of hop extracts in industrial and home brewing processes as an alternative to hop cones or pellets usually added to wort during boiling has become increasingly popular. These extracts represent concentrated sources of bitter compounds, i.e., α- and β-acids, which are involved in some of the main reactions that take place in the wort and are responsible for the bitterness and the final quality of beer. This work aims at proposing a novel extraction technique, using a hydrofluorocarbon solvent in subcritical conditions; this process provided an extraction yield of 19% and an α-acid recovery of approximately 49% in 120 min of process. The α-acid isomerization kinetics of thermally treated hop extracts were studied and compared with those of both hop pellets and a CO2 extract. Laboratory scale tests showed that shorter boiling times were needed using hydrofluorocarbon and CO2 extracts (approximately 25 min and 34 min, respectively) to reach the same isomerization efficiency of 16.73%, achieved in 50 min of boiling with pellets. Moreover, the process was scaled up and the possibility of considerably reducing the conventional treatment times using hydrofluorocarbon extracts was confirmed: the same isomerization yield (9.1%) obtained after 50 min using the traditional procedure with hop pellets was reached in a shorter time of approximately 35 min in a pilot apparatus.

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Section: Resultsmentioning

confidence: 94%

Using Hydrofluorocarbon Extracts of Hop in a Pilot Scale Brewing Process

et al. 2022

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“…Hops have been reported to contain hundreds of valuable ingredients that have a positive effect on health. [9][10][11][12] Recently, hops have attracted the attention of researchers due to the discovery of the antioxidant activity of hops polyphenols. [13,14] Lupulones themselves have sedative, diuretic effects as well as antibacterial properties.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and morphological studies of Tc‐99m‐labeled lupulone‐conjugated Fe₃O₄@TiO₂ nanocomposite, and in vitro cytotoxicity activity on prostate cancer cell lines

Tutun

Tekin

Yasakçı

et al. 2021

Applied Organom Chemis

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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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“…α‐acids are extracted and thermally converted into iso‐α‐acids via an isomerization reaction. These latter compounds are responsible for the bitter taste of beer . β‐acids are also essentially formed by three compounds: Lupulone, Adlupulone, and Colupulone.…”

Section: Introductionmentioning

confidence: 99%

Baseline separation of α and β‐acids homologues and isomers in hop (Humulus lupulus L.) by CD‐MEKC‐UV

et al. 2019

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An alternative method for simultaneous baseline separation of α and β‐acids homologues and isomers in hop by CD‐MEKC with UV detection was proposed. The optimized background electrolyte was composed of 30 mmol/L sodium tetraborate solution, 45 mmol/L sodium dodecyl sulfate, 20 mmol/L β‐cyclodextrin and 10% v/v acetonitrile. The instrumental conditions were evaluated by using a 33 Box‐Benhken experimental design. In order to demonstrate the applicability of the method, 21 hop samples from different varieties were analyzed. The repeatability intra‐ and interday tests were performed and relative standard deviations lower than 7% for area and migration times were observed. The present method comprehended 8 min analysis time and revealed to be faster and more efficient when compared to previous reports from literature.

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Potential impact of medium characteristics on the isomerisation of hop α-acids in wort and buffer model systems

Cited by 18 publications

References 21 publications

Using Hydrofluorocarbon Extracts of Hop in a Pilot Scale Brewing Process

Using Hydrofluorocarbon Extracts of Hop in a Pilot Scale Brewing Process

Synthesis and morphological studies of Tc‐99m‐labeled lupulone‐conjugated Fe₃O₄@TiO₂ nanocomposite, and in vitro cytotoxicity activity on prostate cancer cell lines

Baseline separation of α and β‐acids homologues and isomers in hop (Humulus lupulus L.) by CD‐MEKC‐UV

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Potential impact of medium characteristics on the isomerisation of hop α-acids in wort and buffer model systems

Cited by 18 publications

References 21 publications

Using Hydrofluorocarbon Extracts of Hop in a Pilot Scale Brewing Process

Using Hydrofluorocarbon Extracts of Hop in a Pilot Scale Brewing Process

Synthesis and morphological studies of Tc‐99m‐labeled lupulone‐conjugated Fe3O4@TiO2 nanocomposite, and in vitro cytotoxicity activity on prostate cancer cell lines

Baseline separation of α and β‐acids homologues and isomers in hop (Humulus lupulus L.) by CD‐MEKC‐UV

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Synthesis and morphological studies of Tc‐99m‐labeled lupulone‐conjugated Fe₃O₄@TiO₂ nanocomposite, and in vitro cytotoxicity activity on prostate cancer cell lines