The Open Anchoring Quest Dataset: Anchored Estimates from 96 Studies on Anchoring Effects

People’s estimates are biased toward previously considered numbers (anchoring). We have aggregated all available data from anchoring studies that included at least two anchors into one large dataset. Data were standardized to comprise one estimate per row, coded according to a wide range of variables, and are available for download and analyses online (https://metaanalyses.shinyapps.io/OpAQ/). Because the dataset includes both original and meta-data it allows for fine-grained analyses (e.g., correlations of estimates for different tasks) but also for meta-analyses (e.g., effect sizes for anchoring effects)

On the autoxidation of bitter-tasting iso-alpha-acids in beer

The iso-alpha-acids, the major contributor to bitter beer taste, is well-known to strongly degrade during beer aging. The storage of beer in brown glass bottles revealed a strong depletion of the trans-configured isomers in a highly specific manner, whereas the corresponding cis-iso-alpha-acids seemed to be hardly affected. In comparison, storage of beer in polyethylene terephthalate bottles, which are known to be permeable to oxygen, induced a drastic degradation of both isomers independent of their cis/trans configuration. To investigate the chemical transformation of iso-alpha-acids under oxidative storage conditions, suitable model experiments were performed, and the reaction products that formed were identified as previously not reported hydroperoxy- and hydroxyl-allo-iso-alpha-acids by means of one-/two-dimensional NMR and liquid chromatography-mass spectrometry experiments; for example, cis- and trans-configured hydroperoxy-alloisohumulone as well as the corresponding hydroxy-alloisohumulones were generated upon oxidation of cis- and trans-isohumulone independent of their cis/trans configuration. In addition, the oxidation products formed from the various iso-alpha-acid congeners were quantitatively determined in a series of beer samples stored under defined conditions. For the first time, these data help to understand the molecular mechanism involved in the autoxidative degradation of iso-alpha-acids in beer

18O stable isotope labeling, quantitative model experiments, and molecular dynamics simulation studies on the trans-specific degradation of the bitter tasting iso-alpha-acids of beer

The typical bitterness of fresh beer is well-known to decrease in intensity and to change in quality with increasing age. This phenomenon was recently shown to be caused by the conversion of bitter tasting trans-iso-alpha-acids into lingering and harsh bitter tasting tri- and tetracyclic degradation products such as tricyclocohumol, tricyclocohumene, isotricyclocohumene, tetracyclocohumol, and epitetracyclocohumol. Interestingly, the formation of these compounds was shown to be trans-specific and the corresponding cis-iso-alpha-acids were found to be comparatively stable. Application of 18O stable isotope labeling as well as quantitative model studies combined with LC-MS/MS experiments, followed by computer-based molecular dynamics simulations revealed for the first time a conclusive mechanism explaining the stereospecific transformation of trans-iso-alpha-acids into the tri- and tetracyclic degradation products. This transformation was proposed to be induced by a proton-catalyzed carbon/carbon bond formation between the carbonyl atom C(1') of the isohexenoyl moiety and the alkene carbon C(2'') of the isoprenyl moiety of the trans-iso-alpha-acids

Comprehensive sensomics analysis of hop-derived bitter compounds during storage of beer

For the first time, quantitative LC-MS/MS profiling of 56 hop-derived sensometabolites contributing to the bitter taste of beer revealed a comprehensive insight into the transformation of individual bitter compounds during storage of beer. The proton-catalyzed cyclization of trans-iso-alpha-acids was identified to be the quantitatively predominant reaction leading to lingering, harsh bitter tasting tri- and tetracyclic compounds such as, e.g. the cocongeners tricyclocohumol, tricyclocohumene, isotricyclocohumene, tetracyclocohumol, and epitetracyclocohumol, accumulating in beer during storage with increasing time and temperature. The key role of these transformation products in storage-induced trans-iso-alpha-acid degradation was verified for the first time by multivariate statistics and hierarchical cluster analysis of the sensomics data obtained for a series of commercial beer samples stored under controlled conditions. The present study offers the scientific basis for a knowledge-based extension of the shelf life of the desirable beer's bitter taste and the delay of the onset of the less preferred harsh bitter aftertaste by controlling the initial pH value of the beer and by keeping the temperature as low as possible during storage of the final beverage

Molecular, psychophysical and receptor-based studies on the bitter taste of beer.

Mittels modernsten analytischen Verfahren kombiniert mit psychophysikalischen Studien ist es erstmals gelungen, die bei der Bieralterung ablaufenden stofflichen Umwandlungsreaktionen und damit einhergehenden geschmacklichen Veränderungen in Pilsener Bieren auf molekularer Ebene zu charakterisieren. Als entscheidend erwies sich dabei der Abbau der bitteren iso-α-Säuren, der mit Hilfe von Modellexperimenten sowie spektroskopischen Methoden untersucht wurde. So konnten elf bisher nicht beschriebene Stoffklassen als Abbauprodukte der iso-α-Säuren identifiziert und deren Bildungsweg aufgezeigt werden. Mittels LC-MS/MS-Methoden wurde eine umfassende quantitative Bewertung des Alterungsverhaltens durchgeführt, was in Kombination mit der humansensorischen Bewertung der Bierbitterstoffe eine Beschreibung des Bittergeschmacks auf molekularer Ebene erlaubte. Zudem konnte mittels zellbasierten Assay die humansensorische Bewertung auf Ebene der TAS2R-Bitterrezeptoren verifiziert werden. Diese Ergebnisse bieten die wissenschaftliche Grundlage zur gezielten technologischen Optimierung der Geschmacksqualität sowie der Lagerungsstabilität von Bieren.By means of instrumental analytical methods combined with psychophysical studies, a comprehensive characterization of sensory and chemical changes occurring during beer aging was accomplished on a molecular level. The degradation of iso-α-acids turned out to be the most important transformation reaction. Detailed model studies enabled isolation and identification of 11 specific degradation products and the unequivocal clarification the underlying formation pathways. Besides a quantitative assessment of beer aging via LC-MS/MS, psychophysical characterization of the hop-derived bitter compounds provided a molecular understanding of beer bitterness and its storage-dependent changes. Furthermore, the data of human sensory studies were verified by means of a cell-based assay using TAS2R bitter taste receptors. These results provide the scientific basis for a targeted technological optimization of the taste quality and the shelf-life of beer

Structures of storage-induced transformation products of the beer's bitter principles, revealed by sophisticated NMR spectroscopic and LC-MS techniques

Besides undesirable changes in the attractive aroma, a significant decrease in the intensity of the bitterness as well as a change of the taste into a lingering, harsh bitterness has long been known as a shelf-life limiting factor of beer. Multiple studies have demonstrated that the aging of beer induces a decrease of the total amount of cis- and trans-iso-alpha-acids, the well-known bitter principles of beer. Although the trans-iso-alpha-acids exclusively, not the cis-iso-alpha-acids, were found to be degraded upon storage of beer, the key transformation products formed exclusively from the trans isomers in beer are not known. In the present study, suitable model experiments followed by LC-MS/MS and sophisticated NMR spectroscopic experiments, including the measurement of residual dipolar couplings (RDCs) in gel-based alignment media as well as a novel broadband and B(1)-field-compensated incredible natural abundance double-quantum transfer experiment (INADEQUATE) pulse sequence, enabled the identification of a series of previously unknown trans-specific iso-alpha-acid transformation products, namely, tricyclocohumol, tricyclocohumene, isotricyclocohumene, tetracyclocohumol, and epitetracyclocohumol, respectively. HPLC-MS/MS analysis of these compounds, which exhibit the aforementioned harsh lingering bitter taste and have threshold concentrations ranging from 5 to 70 micromol L(-1), confirmed their generation during aging of beer and, for the first time, explained the storage-induced changes of the beer's bitter taste on a molecular level

LC-MS/MS quantitation of hop-derived bitter compounds in beer using the ECHO technique

A new quantification method for hop-derived bitter compounds in beer was developed. By means of LC-MS/MS operating in the multiple reaction monitoring mode, a total of 26 hop-derived bitter compounds, namely, the post-, co-, n-, ad-, pre-, and adpre-congeners of iso-alpha-acids, alpha-acids, and beta-acids, as well as the prenylflavonoid isoxanthohumol and the chalcone xanthohumol, could be simultaneously detected for the first time in a single HPLC run in authentic beer samples without any cleanup procedures. To compensate for the effect of coextracted matrix components in LC-MS/MS analysis, the so-called ECHO technique was applied for the first time as a suitable strategy for the quantitative analysis of the hop-derived bitter compounds in fresh and stored beer. On the basis of quantitative data, the remarkable instability of alpha-acids and trans-iso-alpha-acids was confirmed, and it was observed that the degradation of trans-iso-alpha-acids during the storage of beer is not dependent from the nature of the alkanoyl side chain of the congeners. In contrast, an increase of the concentrations of beta-acids and of the prenylflavonoid isoxanthohumol as well as of the chalcone xanthohumol during the storage of beer was observed

Arithmetischer Wegweiser, Oder nach Ehst- und Liefländischer Handlung gründlich eingerichtetes Erstes Revalsches Rechenbuch

Titelbl. in Rot- u. Schwarzdr.Vorlageform des Erscheinungsvermerks: Gedruckt zu Halle im Magdeburgischen bey Joh. Justinus Gebauern, Univ. Buchdr. 173

Arithmetischer Wegweiser, Oder nach Ehst- und Liefländischer Handlung gründlich eingerichtetes Erstes Revalsches Rechenbuch

Titelbl. in Rot- u. Schwarzdr.Vorlageform des Erscheinungsvermerks: Gedruckt zu Halle im Magdeburgischen bey Joh. Justinus Gebauern, Univ. Buchdr. 173