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Symposium Introduction
Current Status and Future Perspectives in Flavor Research: Highlights of the 11th Wartburg Symposium on Flavor Chemistry & Biology Thomas Hofmann, Dietmar Krautwurst, and Peter Schieberle J. Agric. Food Chem., Just Accepted Manuscript • DOI: 10.1021/acs.jafc.7b06144 • Publication Date (Web): 03 Jan 2018 Downloaded from http://pubs.acs.org on January 3, 2018
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Journal of Agricultural and Food Chemistry
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Current Status and Future Perspectives in Flavor Research: Highlights of
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the 11th Wartburg Symposium on Flavor Chemistry & Biology
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Thomas Hofmann1,2*, Dietmar Krautwurst2, and Peter Schieberle2,3
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Chair of Food Chemistry and Molecular and Sensory Science, Technische
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Universität München, Lise-Meitner-Str. 34, D-85354 Freising, Germany, and
8 2
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Leibniz-Institute for Food Systems Biology at the Technical University of Munich
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(formerly: Deutsche Forschungsanstalt für Lebensmittelchemie), Lise-Meitner-Str. 34,
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D-85354 Freising, Germany 3
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Lehrstuhl für Lebensmittelchemie, Technische Universität München, Lise-Meitner Strasse 34, D-85354 Freising
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*
To whom correspondence should be addressed
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PHONE
+49-8161/71-2902
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FAX
+49-8161/71-2949
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E-MAIL
[email protected]
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ABSTRACT
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The 11th Wartburg Symposium on Flavor Chemistry & Biology, held at the hotel “Auf
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der Wartburg” in Eisenach, Germany, from June 21 to 24 in 2016, offered a venue for
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global exchange on cutting-edge research in chemistry and biology of odor and taste.
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The focus areas were (1) Functional Flavor Genomics and Biotechnology, (2) Flavor
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Generation and Precursors, (3) New Approaches and Precursors, (4) New
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Approaches
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Relationships, (6) Food-Borne Bioactives and Chemosensory Health Prevention, and
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(7) Chemosensory Reception, Processing, and Perception. Selected from more than
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250 applicants, 160 distinguished scientists and rising stars from academia and
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industry from 24 countries participated in this multidisciplinary event. This special
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issue comprises a selection of 33 papers from oral presentations and poster
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contributions, and is prefaced by this introduction paper to carve out essential
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achievements in odor and taste chemistry and to share future research perspectives.
and
Technologies,
(5)
New
Molecules
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KEYWORDS
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Wartburg symposium, flavor, taste, aroma, chemoreceptors
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Structure/Activity
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History of the Wartburg Symposium. Scientific exchange on flavor research at the
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historical Wartburg Castle in Eisenach, Germany, dates back to 1978, when political
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conflicts between Eastern and Western Europe reached their maximum. At this time,
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Cornelius Weurman, a pioneer of flavor research who later organized the first
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Weurman Symposium in 1975, had the idea to bring together all existing European
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research groups. But he neglected that contacts between East and West European
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scientists were rather difficult at that time and were hindered by the Eastern political
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situation. As most Eastern European scientist did not have the chance to participate
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in meetings organized outside Eastern Europe, Martin Rothe, who introduced the
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consideration of odor thresholds in the evaluation of a compound’s odor contribution,1
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followed the idea to establish a separate Aroma Symposium in Eastern Europe. The
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Wartburg was selected for this symposium because of its historical background as
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well as the central geographic position in Germany. But the political problems could
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not be overcome. The organizers of the 1st Wartburg Aroma Symposium were clearly
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asked by the East German government, not only to select participants under
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scientific, but also political aspects. Considering this difficult situation, the organizers
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were proud about the active participation of eight well-known West European
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scientists, among them Werner Grosch, one of the inventors of the aroma extract
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dilution analysis (AEDA) and the odor activity value (OAV) concept,2 which was later
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further refined by Peter Schieberle,3,4 one of the organizers of the Wartburg
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symposium. In the past 40 years, the Wartburg Symposium has convened every
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three years and is today internationally respected as one of the most influential
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international symposia on flavor chemistry with firmly established bridges to biology
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and neurophysiology of smell and taste.
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Achievements in Flavor Research. Primarily driven by the introduction of
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gas chromatography in the nineteen sixties, the primary objective in the early days of ACS Paragon Plus Environment
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flavor research was to characterize as many volatiles in foods as possible. This led to
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the identification of about 8,000 volatiles and supported the prediction of a total of
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~10,000 volatiles to occur in foods.5,6 However, dose/activity considerations fed
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increasing doubts that the typical aroma of a given food is caused by a huge number
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of volatiles, and Martin Rothe, the founder of the Wartburg symposium, was one of
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them.1-3 This induced a paradigm shift in flavor research, fueled by the birth of GC-
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olfactometry (GC-O), enabling the localization of aroma-relevant odorants among the
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bulk of sensorially inactive volatiles in the chromatographic effluent by human
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“sniffing” detection.7-10 By repeated GC-O analysis of serially diluted aroma distillates,
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charm analysis10 or aroma extract dilution analysis (AEDA)2-4,10 even allowed the
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ranking of the odorants detected with respect to their sensory impact, and helped to
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focus the laborious identification experiments on the most intense food odorants. As
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the GC-O screening of key odorants is based on their threshold in air and not in the
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respective food matrix, researchers then started to study the contribution of individual
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odorants to a given food aroma on the basis of “odor activity values” (OAV) defined
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as the ratio of the concentration of an odorant in the food and its odor threshold in an
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appropriate matrix.1-4,12-14 This concept demonstrated that the rather unlimited
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variations in food flavors are due to a “combinatorial chemosensory code” (Figure
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1A), comprising a surprisingly small center group of 3-40 volatile key food odorants
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among the several ten thousands of non-odor active food constituents.
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In the early years of the new millennium, flavor chemistry was expanded by
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applying the principle of bioresponse-guided identification of odorants to non-volatile
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taste-active compounds. In particular, the application of the taste dilution analysis
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(TDA)15 and the comparative taste dilution analysis (cTDA)16 have led to the
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discovery of previously unknown key taste molecules and taste modulators in
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thermally processed foods like chicken broth,17 beef juice,18 hazelnuts,19 cooked ACS Paragon Plus Environment
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crustaceans,20 roasted coffee,21 fermented foods like Gouda and Parmesan
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cheese,22-25 red wine,26 beer and hops,27,28 black tea,29 fish sauce,30 balsamic
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vinegar,31 and yeast extracts,32 and plant-derived products like cocoa,33 Tasmanian
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pepper,34 carrots,35 and asparagus,36 respectively. Very recently, for the first time,
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odorants have been discovered to exhibit taste modulatory function, e.g. (R)-
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citronellal has been reported to attenuate caffeine bitterness by inhibiting the bitter
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receptors TAS2R43 and TAS2R46.37
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Counteracting analytical challenges in accurate quantitation of odorants and
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tastants, which are largely differing in concentration, volatility, and chemical stability,
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the so-called stable isotope dilution analysis (SIDA) was introduced in flavor
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research, using stable isotope (13C, 2H)-labeled twin molecules of the odorants and
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tastants as most suitable internal standards for GC-MS and LC-MS analysis.2-4,10,38-40
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Most impressively, minimal chemosensory recombinates of 3 to 40 key odorants and
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15-40 key tastants have been demonstrated to be truly necessary and sufficient for
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“synthesizing” the authentic percept of a specific food’s odor such as, e.g. black tea41
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and red wine (Figure 1B),39 although the overall flavor quality was not represented
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by any of the single ingredients alone.42 Therefore, the key mechanism by which the
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brain encodes perceptual representations of behaviorally relevant food items is
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through the synthesis of combinatorial chemosensory inputs into a unique perceptual
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experience (“flavor object”), rather than through individual molecules.42 In
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contradiction to traditional views, the sheer unlimited variations in food flavors is
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today accepted to be due to a “combinatorial chemosensory code” (Figure 1A)
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comprising a surprisingly small center group of 3-40 volatile key food odorants and
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10-40 non-volatile key food tastants among the several ten thousands of food
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constituents.31,39,42
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The hedonic differentiation and evaluation of these food flavor signatures is
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due to the high discriminatory power of the olfactory and gustatory system.42,43 A
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food’s chemical flavor profile is translated into specific receptor activity patterns
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elicited by the interaction of the mixture of chemosensory key molecules with their
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best cognate receptors out of the ~400 olfactory und ~30 taste receptors, among
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which sweet and umami tastes are mainly mediated by TAS1R receptor
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heterodimers44-46 while the perception of bitterness is mediated by 25 G-protein-
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coupled TAS2R receptors.47-49 Although these flavor objects enable us to make food
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choice decisions, surprisingly little is known about the human receptor activation
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patterns for single food odorants and tastants, and nothing is known about receptor
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codes for chemosensory mixtures as recently exemplified for the odorant receptor
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code of cultured butter (Figure 1C).50 Moreover, knowledge is rather limited on the
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complementation as well as co-activation of bitter taste receptors by the various
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bitter-tasting molecules present in foods and beverages such as, e.g. beer,51
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cheese,52 stevia extract,53 carrots, and coffee (unpublished data), respectively
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(Figure 2). In consequence, the minimal chemosensory recombinates, rather than
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individual stimuli, seem to be most promising “molecular probes” for future research
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to decode the mechanisms triggering food preference and aversive behaviors.
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Scientific Challenges and Future Perspectives. Today’s challenges in
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flavour research are multifold: To overcome flavor defects in healthy food products,
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reduced in salt, sugar, monosodium glutamate (MSG), and fat, respectively, the food
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and nutrition sector relies on new solutions and technologies capable of fine-tuning
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aroma deviations as well as the use of natural and/or biosynthetic, high-potency taste
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modulation systems for the delivery of truly authentic flavor signatures.
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Independent from their sensory quality, most food-borne key odorants/tastants
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are generated from precursors in the raw materials upon processing and/or ACS Paragon Plus Environment
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fermentation of foods and their generation is strongly dependent on the processing
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conditions. Representing the molecular blueprint of our food’s chemosensory
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signature, the population of key flavor compounds, coined “sensometabolome”,24
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may be used as a molecular target for visualizing the changes in odor and taste
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profiles from the raw materials through the various manufacturing process
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intermediates all the way up-stream to the consumer’s plate by high-precision and
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high-throughput mass spectrometric profiling. This will open new avenues for a more
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scientifically directed taste improvement of foods by tailoring processing parameters
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(“molecular food engineering”); for example, targeted food-borne generation of high-
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potency salt, sweet, umami, or mouthfullness (kokumi) enhancers will help to
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overcome taste defects in salt, sugar, and MSG-reduced food products without
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artificial ingredients. Also the efficient control of bitter off-tastes of food products and
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phytochemical supplemented products might be possible by suppressing bitter taste
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perception by means of controlled generation of food-borne bitter inhibitors.
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Molecular knowledge of the odor code of crops and vegetables holds promise
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for major improvements in future breeding strategies, which in the past have been
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targeted primarily towards field performance, yield, and storage characteristics, while
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ignoring quality traits such as aroma and taste. The analytical assessment of the key
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odorants and tastants would greatly facilitate the accurate evaluation of a large
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number of progeny, thus moving the selection of flavor earlier in the selection
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sequence and increasing the chance of finding truly superior new cultivars for a wide
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cross-section of food crops. Therefore, advances in flavor chemistry and biology hold
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promise to become truly a game-changer helping to transform the incremental
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product improvement approaches of our today’s industry into a consumer-centric re-
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engineering strategy, more effectively targeting food development to consumers’
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preference, acceptance, and needs. ACS Paragon Plus Environment
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To achieve all this, we need modern analytical technologies to speed up the
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discovery of unknown chemosensory active molecules in nature’s unlimited box of
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molecules and to understand their physico-chemical interactions with food matrix
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constituents on a molecular level. We need to learn how to optimize the gene
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computer of plants and to utilize the biosynthetic power of plants and microorganisms
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to produce target flavor molecules in high yields and also high enantioselectivity. In
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addition, we should use our knowledge on the combinatorial chemosensory codes for
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a targeted navigation of breeding and post-harvest processing parameters to support
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plant breeders in the development of premium tasty plant materials.
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New research is required to increase our knowledge on the molecular
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alterations of salivary composition upon stimulation with odorants and tastants,54,55 as
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well as the receptor proteins involved in sensing of odorants, tastants, and additional
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stimuli such as fat. We need to understand how our foods’ combinatorial
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chemosensory codes are translated into food-specific chemosensory receptor
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activation patterns and how this can be modulated to develop premium tasty and
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healthy food products with reduced levels of, e.g., salt, sugar, and fat.
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More fundamental knowledge is urgently needed from the secretion of
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neurotransmitters to the induction of neural activity that is conveyed to the cerebral
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cortex to represent the distinct odor and taste qualities. As food preferences and
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aversions have been reported to develop across life stages and individual differences
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in chemosensory receptor genotypes to affect flavor experience and food selection,56-
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genotypic differences with respect to sensory preference for and aversion against
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food flavors. Intriguingly, the conditioned aversion for odorants in mice has been
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shown to be maintained over two generations60, indicating epigenetic modification to
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play a key role not only in mono-allelic odorant receptor gene activation,61 but also in
we need to entangle individual age-dependent chemosensory pheno- and
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sensory programming and development of nutritional preferences/aversions across
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life stages.62 Last but not least, we have to furtherance our knowledge on the
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biotransformation of odorants and tastants in the nasal and oral cavity, but also on
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the biological response induced upon their ingestion.
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Without any doubt, advancement in these fields will crucially depend on how
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consequently scientists will dare to leave the trampling paths of their own disciplines,
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and will learn to live up their science in a interdisciplinary environment, striving to
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generate synergies by bundling the different expertise and technology know-how of
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research in food and natural product chemistry, psychophysics and sensory science,
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nutrition and health sciences, biotechnology, plant biology and genetics, human
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biology, genetics and neurophysiology, respectively. Exactly this profile rounds out
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the Wartburg Symposium’s characteristic signature as a fruitful retreat to discuss
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emerging cross-disciplinary challenges in a relaxing atmosphere.
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The 11th Wartburg Symposium on Flavor Chemistry & Biology. To tackle
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these truly cross-disciplinary research challenges, top-tier flavor chemistry and
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biology once more returned back to the “Hotel on the Wartburg” in Eisenach,
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Germany. Between June 21 and 24 in 2016, this symposium offered a venue for
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global exchanges and knowledge calibration of the state of the art research in flavor
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chemistry and biology and for the presentation and discussion of latest advances and
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future research opportunities. Compared to its infant days, flavor research has
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embarked on a journey beyond its traditional core disciplines in chemistry and
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sensory analysis, and has begun to valorize the sweet spots emerging at the
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intersection with biotechnology, human biology, and neurophysiology.
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Selected from more than 250 applicants, 160 distinguished scientists and
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rising stars from academia and industry from 24 countries and 4 continents
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participated in this highly multidisciplinary event on the historic castle (Figure 3). ACS Paragon Plus Environment
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Experts from analytical and natural product chemistry, psychophysics and sensory
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science, nutrition and health sciences, biotechnology, plant biology and genetics,
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human biology and neurophysiology, and imaging technologies shared expertise and
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new insights, calibrated their knowledge, and exchanged on future perspectives.
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This special issue presents a selection of 33 papers from oral and flash poster
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presentations and poster contributions shown in the thematic symposium sessions
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(1) Functional Flavor Genomics and Biotechnology, (2) Flavor Generation and
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Precursors, (3) New Approaches and Precursors, (4) New Approaches and
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Technologies, (5) New Molecules and Structure/Activity Relationships, (6) Food-Born
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Bioactives and Chemosensory Health Prevention, and (7) Chemosensory Reception,
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Processing and Perception, and demonstrates the depth and broad scope of the
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science presented at the Wartburg symposium. The former idea of bringing together
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people from Eastern and Western Europe was replaced in favour of building
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multinational bridges between different scientific disciplines – and this will also shape
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the unique signature of future Wartburg Symposia.
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The 12th Wartburg Symposium in 2019. The next Wartburg Symposium on
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Flavor Chemistry & Biology will be held from May 21 to May 24, 2019 at the historic
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Wartburg Castle. If you want to see the latest developments at the intersection of
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chemistry and biology of flavors, make your plans to be there.
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ACKNOWLEDGEMENT
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The organizers are grateful to all the sponsors for their generous support, which
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helped to offset the travel expenses of invited speakers and other costs to run the
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symposium: the Gold sponsors, namely, PepsiCo, Mars, Nestle, Altria, General Mills, ACS Paragon Plus Environment
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DSM, and Philip Morris; the Silver sponsors, namely Döhler, Hasegawa, Givaudan,
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Lucta, Takasago, Symrise, Gerstel, and Mondelez; and the Bronze sponsors, namely
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Ajinomoto, Aromalab, Wakunaga, Bell Flavors, Flavologic, and the American
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Chemical Society (ACS). In addition, we thank the German Research Center for
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Food Chemistry, and the Technical University of Munich for supporting the
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organization of the symposium with staff and expertise, in particular, Corinna Dawid
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for planning and organization of the symposium and Andreas Dunkel for the technical
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support. We also would like to thank the Wartburg Stiftung and, in particular, Andreas
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Volkert, for making it again possible to use the stimulating historic place with the
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knights hall for that symposium, and the hotel staff for creating a friendly and warm
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atmosphere in the hotel “Auf der Wartburg”.
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13. Wagner, J.; Granvogl, M.; Schieberle, O. Characterization of the key aroma
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compounds in raw licorice (Glycyrrhiza glabra L.) by means of molecular
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15. Frank O., Ottinger H., Hofmann T. (2001) Characterization of an Intense Bitter-
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tasting 1H,4H-Quinolizinium-7-olate by Application of the Taste Dilution
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Analysis, A Novel Bioassay for the Screening and Identification of Taste-active
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(2003) Discovery and Structure
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Determination of a Novel Maillard-Derived Sweetness Enhancer by Application
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of the Comparative Taste Dilution Analysis (cTDA). J. Agric Food Chem., 51,
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17. Dunkel, A.; Hofmann, T., Sensory-directed identification of beta-alanyl
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dipeptides as contributors to the thick-sour and white-meaty orosensation
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induced by chicken broth. J. Agric. Food Chem. 2009, 57, 9867-77.
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18. Ottinger, H.; Hofmann, T., Identification of the taste enhancer alapyridaine in
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beef broth and evaluation of its sensory impact by taste reconstitution
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experiments. J. Agric. Food Chem. 2003, 51, 6791-6796.
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19. Singldinger, B.; Dunkel, A.; Hofmann, T. The cyclic diarylheptanoid asadanin as
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the main contributor to the bitter off-taste in hazelnuts (Corylus avellana L.). J.
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20. Meyer, S.; Dunkel, A.; Hofmann, T., Sensomics-Assisted Elucidation of the
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Tastant Code of Cooked Crustaceans and Taste Reconstruction Experiments.
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21. Frank, O.; Zehentbauer, G.; Hofmann, T. Bioresponse-guided decomposition of
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roast coffee beverage and identification of key bitter taste compounds, Eur.
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Food Res. Technol. 2005, 222, 492-508.
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22. Toelstede, S.; Dunkel, A.; Hofmann, T., A Series of Kokumi Peptides Impart the
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Long-Lasting Mouthfulness of Matured Gouda Cheese. J. Agric. Food Chem.
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2009, 57, 1440-1448.
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23. Toelstede, S.; Hofmann, T., Quantitative studies and taste re-engineering
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experiments toward the decoding of the nonvolatile sensometabolome of Gouda
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cheese. J. Agric. Food Chem. 2008, 56, 5299-5307.
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24. Toelstede, S.; Hofmann, T., Sensomics mapping and identification of the key
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bitter metabolites in Gouda cheese. J. Agric. Food Chem. 2008, 56, 2795-2804.
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25. Hillmann, H.; Hofmann, T. Quantitation of key tastants and re-engineering the
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taste of Parmesan cheese. J. Agric. Food Chem. 2016, 64, 1794-805. 26. Hufnagel, J. C.; Hofmann, T., Quantitative reconstruction of the nonvolatile sensometabolome of a red wine. J. Agric. Food Chem. 2008, 56, 9190-9199.
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27. Intelmann, D.; Haseleu, G.; Dunkel, A.; Lagemann, A.; Stephan, A.; Hofmann,
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T. Comprehensive sensomics analysis of hop-derived bitter compounds during
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storage of beer. J. Agric. Food Chem. 2011, 59, 1939-1953.
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28. Dresel, M.; Vogt, Ch.; Dunkel, A.; Hofmann, T. The bitter chemodiversity of hops (Humulus lupulus L.). J. Agric. Food Chem., 2016, 64, 7789–7799.
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29. Scharbert, S.; Holzmann, N.; Hofmann, T. Identification of the astringent taste
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compounds in black tea infusions by combining instrumental analysis and
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human bioresponse, J. Agric. Food Chem. 2004, 52, 3498–3508.
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30. Schindler, A.; Dunkel, A.; Stähler. F.; Backes, M.; Meyerhof, W.; Hofmann, T.
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Discovery of salt taste enhancing arginyl dipeptides in protein digests and
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fermented fish sauces by means of a sensomics approach. J. Agric Food
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Chem. 2011, 59, 12578-12588.
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31. Hillmann, H.; Mattes, J.; Brockhoff, B.; Dunkel, A.; Meyerhof, W.; Hofmann, T.
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Sensomics analysis of taste compounds in balsamic vinegar and discovery of 5-
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acetoxymethyl-2-furaldehyde as a novel sweet taste modulator. J. Agric. Food
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Chem. 2012, 60, 9974–9990.
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32. Festring, D.; Hofmann, T., Discovery of N(2)-(1-carboxyethyl)guanosine 5'-
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monophosphate as an umami-enhancing maillard-modified nucleotide in yeast
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extracts. J. Agric. Food Chem. 2010, 58, 10614-22.
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33. Stark, T.; Hofmann, T. Isolation, structure determination, synthesis, and sensory
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activity of N-phenylpropenoyl-L-amino acids from cocoa (Theobroma cacao), J.
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Agric. Food Chem. 2005, 53, 5419–5428.
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34. Mathie, K.; Lainer, J.; Spreng, S.; Dawid, C.; Andersson, D.A.; Bevan, S.;
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Hofmann, T. Structure–pungency relationships and TRP channel activation of
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drimane sesquiterpenes in Tasmanian pepper (Tasmannia lanceolata). J. Agric.
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Food Chem., 2017, 65, 5700–5712.
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35. Czepa, A.; Hofmann, T. Structural and sensory characterization of compounds
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contributing to the bitter off-taste of carrots (Daucus carota L.) and carrot puree,
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J. Agric. Food Chem. 2003, 51, 3865–3873.#
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36. Dawid, C.; Hofmann, T. Structural and sensory characterization of bitter tasting
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steroidal saponins from Asparagus apears (Asparagus officinalis L.), J. Agric.
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Food Chem. 2012, 60, 11889–11900.
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37. Suess, B.; Brockhoff, A.; Meyerhof, W.; Hofmann, T. The odorant (R)-citronellal
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attenuates caffeine bitterness by inhibiting the bitter receptors TAS2R43 and
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TAS2R46. J. Agric. Food Chem. 2017, DOI: 10.1021/acs.jafc.6b03554
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38. Kiefl, J.; Pollner, G.; Schieberle, P. Sensomics analysis of key hazelnut
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odorants (Corylus avellana L. 'Tonda Gentile') using comprehensive two-
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dimensional gas chromatography in combination with time-of-flight mass
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spectrometry (GC×GC-TOF-MS). J. Agric. Food Chem. 2013, 61, 5226-5235.
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39. Frank, S.; Wollmann, N.; Schieberle, P.; Hofmann, T. Reconstitution of the
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flavor signature of Dornfelder red wine on the basis of the natural
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concentrations of its key aroma and taste Compounds. J. Agric. Food Chem.
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2011, 59, 8866-8874.
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40. Stark T., Justus H., Hofmann T. Quantitative analysis of N-phenylpropenoyl-L-
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amino acids in roasted coffee and cocoa powder by means of a stable isotope
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dilution assay. J. Agric. Food Chem. 2006, 54, 2859-2867.
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41. Schieberle P., Hofmann T. In: Food Flavors - Chemical, Sensory and
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Technological Properties (H. Jelen, ed.); CRC Press, Taylor and Francis Group,
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2011, pp. 411-437.
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42. Dunkel, A.; Steinhaus, M.; Kotthoff, M.; Nowak, B.; Krautwurst, D.; Schieberle,
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P.; Hofmann, T. Nature’s chemical signatures in human olfaction: a foodborne
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perspective for future biotechnology. Angew. Chem. Int. Ed. 2014, 53, 7124-714
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43. Olender, T.; Waszak, S.; Viavant, M.; Khen, M.; Ben-Asher, E.; Reyes, A.;
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44. Li, X.; Staszewski, L.; Xu, H.; Durick, K.; Zoller, M.; Adler, E. Human receptors
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for sweet and umami taste. Proc. Natl. Acad. Sci USA 2002, 99, 4692-4696.
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45. Behrens, M.; Meyerhof, W.; Hellfritsch, C.; Hofmann, T. Sweet and umami
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taste: natural products, their chemosensory targets, and beyond. Angew. Chem.
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48. Chandrashekar, J.; Mueller, K.L.; Hoon, M.A.; Adler, E.; Feng, L.; Guo, W.;
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Zuker, C.S.; Ryba, N.J. T2Rs function a bitter taste receptors. Cell 2000, 100,
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49. Matsunami, H.; Montmayeur, J.P.; Buck, L.B. A family of candidate taste receptors in human and mouse. Nature 2000, 404, 601-604.
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50. Geithe, C.; Andersen, G.; Malki, A., Krautwurst, D. A butter aroma recombinate
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activates human class-I odorant receptors. J. Agric. Food Chem. 2015, 63,
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9410-9420.
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51. Intelmann, D.; Batram, C.; Kuhn, Ch.; Haseleu, G.; Meyerhof, M.; Hofmann, T.
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Three TAS2R bitter taste receptors mediate the psychophysical responses to
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bitter compounds of hops (Humulus lupulus L.) and beer, Chem. Percept. 2009,
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2, 118-132.
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52. Kohl, S.; Behrens, M.; Dunkel, A.; Hofmann, T.; Meyerhof, W. Amino acids and
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peptides activate at least five members of the human bitter taste receptor
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family. J. Agric. Food Chem. 2013, 61, 53-60.
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psychometric and taste receptor responses to steviol glycosides. J. Agric. Food
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54. Delius, J.; Médard, G.; Kuster, B.; Hofmann, T. Effect of astringent stimuli on
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salivary
protein
interactions
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by
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approaches. J. Agric. Food Chem. 2017, 65, 2147-2154.
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55. Stolle, T.; Grondinger, F.; Dunkel, A.; Meng, C.; Médard, G.; Kuster, B.;
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56. Doty, R.L.; Kamath, V. The influences of age on olfaction: a review. Front Psychol. 2014, 5, 20. eCollection 2014 57. Mennella, J.A.; Finkbeiner, S.; Reed, D.R. The proof is in the pudding: children prefer lower fat but higher sugar than do mothers. Int. J. Obes. 2012, 36, 1285.
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Figure Legend
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Figure 1.
(A) Heatmap displaying odor activity values (OAVs) of the 226 key food
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odorants (KFOs) characterized in 227 food samples.42 (B) Sensory
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profile of an authentic red wine vs. a minimal biomimetic flavor
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recombinate comprising 28 key food odorants and 35 key food
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tastants.39 (C) EC50-based odorant receptor activation barcodes elicited
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by a minimal recombinant exemplified with a 3-compound recombinate
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of cultured butter aroma.50
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Figure 2.
tastants in beer, coffee, carrots, cheese, and Stevia.
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Bitter taste receptor complementation and co-activation by bitter
Figure 3.
The global science community met at the hotel “Auf der Wartburg” in
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Eisenach, Germany, from June 21 to 24 in 2016, to participate in the
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11th Wartburg Symposium on Flavor Chemistry & Biology.
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Figure 2 (Hofmann et al.)
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Figure 3 (Hofmann et al.)
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