Sauerteigbrot ist aufgrund seines einzigartigen Geschmacks‐ und Aromaeindrucks bei Konsumenten überaus beliebt. Die humansensorische Analyse stellt ein wichtiges Verfahren zur Kontrolle der Geschmacks‐ und Aromaqualität dar. Um das Brotflavor objektiv beurteilen und verbessern zu können, ist ein besseres Verständnis der chemosensorischen Signatur von Sauerteigbrot notwendig. Allerdings sind die Schlüsselsensometabolite, die für den typischen Geschmack und das Aroma von Sauerteigbrotkrume verantwortlich sind, bislang nur unzureichend in der Literatur beschrieben. Mit dem Ziel die wertgebenden Geschmacks‐ und Geruchsstoffe von Sauerteigbrotkrume zu entschlüsseln, wurde im Rahmen der vorliegenden Arbeit das Sensomics‐Konzept angewendet. Nach erfolgter Geschmacksprofilanalyse wurden die Basisgeschmacksstoffe in Sauerteigbrotkrume identifiziert und quantifiziert. Um den Beitrag der einzelnen Geschmacksstoffe zum Gesamtgeschmack abzuschätzen, wurden die sogenannten Dose‐over‐Threshold‐Faktoren unter Einbeziehung der jeweiligen Schwellenwerte berechnet. Mithilfe von Rekombinationsexperimenten konnte der authentische Geschmack von Sauerteigbrotkrume mit 14 geschmacksaktiven Substanzen rekonstruiert werden. Omissionsexperimente zeigten, dass zehn dieser Sensometabolite hinreichend sind, um den Geschmack der Sauerteigbrotkrume erfolgreich nachzubilden und diese somit die Schlüsselgeschmacksstoffe darstellen. Unter Einbezug von Literaturdaten zu den Geruchsstoffen von Sauerteigbrotkrume wurde zudem ein Aromavollrekombinat hergestellt und insgesamt elf flüchtige Verbindungen als Schlüsselaromastoffe von Sauerteigbrotkrume identifiziert. Basierend auf diesen Ergebnissen wurde eine Hochdurchsatzmethodik, bestehend aus einer schnellen Probenaufarbeitung mit Stabilisotopenverdünnungsanalyse (SIVA) und einer Ultra‐Hochleistungsflüssigchromatographie‐Tandem Massenspektrometrie (UHPLC‐MS/MS)‐Methode, entwickelt und validiert. Erstmals konnten sowohl die flüchtigen Schlüsselaromastoffe als auch die nichtflüchtigen Schlüsselgeschmacksstoffe von Sauerteigbrotkrume durch Derivatisierung mit 3Nitrophenylhydrazin (3NPH) simultan quantifiziert werden. Ferner wurden verschiedene kommerziell erhältliche Brote mithilfe der entwickelten Methode in einer quantitativen Studie miteinander verglichen. Konzentrationsunterschiede zwischen den Brotproben konnten mit den verwendeten Getreidesorten und Arten der Fermentation in Zusammenhang gebracht werden. Die ermittelten Schlüsselgeschmacksstoffe und aromastoffe eignen sich deshalb als Markermoleküle, um im Zuge der industriellen Brotherstellung gezielt sensorisch verbesserte Sauerteigprodukte herstellen zu können. Nach Entschlüsselung der chemosensorischen Signaturen von Sauerteigbroten beschäftigte sich der zweite Teil der Arbeit damit, wie sich durch eine geeignete räumliche Verteilung von Salz in der Brotkrume, dessen Geschmacksintensität beeinflussen und eine Reduktion des Kochsalzeinsatzes bei gleichbleibender Sensorik erreichen lässt. Der Natriumgehalt in Lebensmitteln wie Brot soll verringert werden, da eine übermäßige Natriumzufuhr ein erhöhtes Risiko für Bluthochdruck und Herz‐Kreislauf‐Erkrankungen bewirkt. Um eine wissenschaftliche Basis für die Methode der inhomogenen Natriumverteilung zu erarbeiten, die eine Salzreduktion ohne Zusätze ermöglicht, wurde der Einfluss der inhomogenen Natriumverteilung auf die Geschmackswahrnehmung systematisch untersucht. Dabei wurde Natriumchlorid räumlich inhomogen in einer stärkebasierten Modellmatrix bzw. in Brotkrume verteilt. Unter der Bedingung, dass der Konzentrationskontrast zwischen den Schichten ausreichend groß war, wurde durch die inhomogene Natriumverteilung eine signifikante Verstärkung der Salzwahrnehmung im Vergleich zur homogenen Verteilung erzielt. Das räumliche Verteilungsmuster der inhomogenen Proben ist dabei nicht ausschlaggebend für den Effekt der Salzverstärkung. Zukünftig kann das sogenannte „Prinzip des sensorischen Kontrasts“ beispielsweise im Bereich 3D‐gedruckter Lebensmittel effektiv genutzt werden, um Lebensmittel mit niedrigerem Salzgehalt bei gleichbleibendem Geschmacksprofil zu entwickeln.

Out of the broad selection of analytical methods applied in metabolomic studies, liquid chromatography coupled to mass spectrometry (LC-MS) has the highest coverage potential. In that regard, the quality of the separation process is crucial for the analytical outcome. Reversed-phase (RP) and hydrophilic interaction liquid chromatography (HILIC) are widely applied, and the potential of various setups to combine these modes for more complementary data has been deeply explored. In our previous study on the orthogonality of LC conditions in the field of metabolomics, combinations of a mixed-mode phase with parallel RP and ion-exchange (IEX) properties and several HILIC columns exhibited the widest compound distributions in a two-dimensional (2D) separation space. For further performance evaluation, an offline comprehensive 2D-LC-TOF-MS (LC×LC-TOF-MS) system was set up with the mixed RP/IEX mode in the first dimension (1D) and HILIC mode in the second dimension (2D). The transfer of fractions to the HILIC column and the effect of offline fraction preparation procedures (dilution and evaporation approaches) were comparatively investigated by using reference substances. In addition, the separation performance of the offline LC×LC-TOF-MS system with and without offline fraction preparation was assessed in comparison to other common LC-TOF-MS strategies (direct flow injection DFI, 1D-LC, serial coupling LC) by the number of detectable features in a human urine sample. In conclusion, the direct transfer of 5 µL fraction volumes without offline treatment was the most promising approach for future application in untargeted metabolomic studies for marker identification from human urine.

The study focuses on the comprehensive analysis of glutamyl dipeptides in cheese, particularly their formation during the cheese ripening process and the influence of various factors, such as origin, the use of various mold cultures, and cheese types. For the first time, all three subgroups of glutamyl dipeptides, namely alpha-Glu-X, X-Glu, and gamma-Glu-X, are covered in a comprehensive analytical LC-MS/MS method offering robust quantitation of all 56 glutamyl dipeptides. The workflow includes a simplified extraction protocol and an optimized separation of the analytes on the stationary phase. Validation experiments demonstrate the method's reliability, including repeatability, detection limits, and recovery. The comprehensive analysis of all glutamyl dipeptides in 122 cheese samples with ripening times between 2 weeks and 15 years shows a strong increase in all peptide classes with prolonged ripening and particularly in the presence of mold.

Rapeseed products, such as protein concentrates, hold promise for addressing global protein demands, but their application in food products is limited by their bitter and astringent taste. This study investigates the use of β-glucosidase (BG) and laccase (LAC) enzymatic treatment, individually and combined, to enhance the flavor of rapeseed protein concentrate (RPC). Untargeted metabolomics and sensory analysis reveal that LAC reduces the bitter compound kaempferol 3-O-(2‴-O-sinapoyl-β-D-sophoroside) (K3OSS) as well as a general reduction in other phenolic compounds, which correlates with a significant decrease in bitterness and astringency. In contrast, BG treatment elevates the levels of K3OSS and is accompanied by increased bitterness due to the conversion of precursor compounds to K3OSS. In addition, the synergistic use of both enzymes significantly reduces the concentration of K3OSS, resulting in a lower perception of bitterness. The LC-MS analysis of pure reference compounds treated with LAC and BG confirms that BG-mediated treatment facilitates the breakdown of larger kaempferol glycosides into K3OSS, while LAC treatment promotes polyphenol polymerization. Consequently, LAC treatment seems to be an effective strategy to improve the sensory quality of RPC and make it more suitable for human consumption.

ADVERTISEMENT RETURN TO ISSUEEditorialNEXTFostering Inclusive Scientific Communities: A Pathway to Innovation in AgricultureLaura L. McConnellLaura L. McConnellMore by Laura L. McConnellhttps://orcid.org/0000-0001-6142-0656 and Thomas HofmannThomas HofmannMore by Thomas Hofmannhttps://orcid.org/0000-0003-4057-7165Cite this: ACS Agric. Sci. Technol. 2024, 4, 1, 1–3Publication Date (Web):January 15, 2024Publication History Received21 December 2023Accepted21 December 2023Published online15 January 2024Published inissue 15 January 2024https://pubs.acs.org/doi/10.1021/acsagscitech.3c00586https://doi.org/10.1021/acsagscitech.3c00586editorialACS PublicationsCopyright © 2024 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views355Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (1003 KB) Get e-AlertscloseSUBJECTS:Agriculture,Food,Gene delivery,Nanomaterials,Pest control Get e-Alerts

Several compounds with taste-modulating properties have been investigated, improving the taste impression without having a pronounced intrinsic taste. The best-known representatives of umami taste-modulating compounds are ribonucleotides and their derivatives. Especially the thio derivatives showed high taste-modulating potential in structure-activity relationship investigations. Therefore, this study focuses on the formation of guanosine 5 '-monophosphate derivatives consisting of Maillard-type generated compounds like the aroma-active thiols (2-methyl-3-furanthiol, 3-mercapto-2-pentanone, 2-furfurylthiol) and formaldehyde to gain insights into the potential of combinations of taste and aroma-active compounds. One literature-known (N-2-(furfurylthiomethyl)-guanosine 5 '-monophosphate) and three new derivatives (N-2-(2-methyl-1-furylthiomethyl)-guanosine 5 '-monophosphate, N-2-((5-hydroxymethyl)-2-methyl-1-furylthiomethyl)-guanosine 5 '-monophosphate, N-2-((2-pentanon-1-yl)thiomethyl)-guanosine 5 '-monophosphate) were successfully produced using green natural deep eutectic solvents and isolated, and their structures were completely elucidated. Besides the intrinsic taste properties, the kokumi and umami taste-modulating effects of the four derivatives were evaluated via psychophysical investigations, ranging from 19 to 22 mu mol/L.

The lignan secoisolariciresinol (SECO) diglucoside (SDG) is a phytoestrogen with diverse effects. LuUGT74S1 glucosylates SECO to SDG, whereby only small amounts of the monoglucoside SMG are formed intermediately, which exhibit increased activity. To identify critical amino acids that are important for enzymatic activity and the SMG/SDG ratio, 3D structural modeling and docking, as well as site-directed mutation studies, were performed. Enzyme assays with ten mutants revealed that four of them had identical kinetic data to LuUGT74S1, while three showed reduced and one increased catalytic efficiency kcat/Km. S82F and E189L substitutions resulted in the complete absence of activity. A17 and Q136 are crucial for the conversion of SMG to SDG as A17S and Q136F mutants exhibited the highest SMG/SDG ratios of 0.7 and 0.4. Kinetic analyses show that diglucosylation is an essentially irreversible reaction, while monoglycosylation is kinetically favored. The results lay the foundation for the biotechnological production of SMG.

A recently published untargeted metabolomics approach toward marker compounds of cocoa germination revealed and identified 12-hydroxyjasmonic acid sulfate, (+)-catechin, and (-)-epicatechin as the most downregulated compounds and two hydroxymethylglutaryl glucosides (HMG gluc) A and B, among others, as the decisive upregulated compounds in the germinated material. These findings were quantitatively evaluated using ultrahigh-performance liquid chromatography-tandem mass spectrometry not only in previously examined sample material but also in a vastly expanded array of cocoa samples of different provenience and process and in cocoa products such as cocoa liquor and chocolate. Hereby, yields of newly identified HMG gluc derivatives could be determined in raw, fermented, germinated, and alternatively processed cocoa, and isomers of HMG gluc A and B could be established as key process indicators. Based on unsupervised clustering and supervised classification, models could identify germinated samples in testing sets consisting of raw, fermented, and germinated samples.

ADVERTISEMENT RETURN TO ISSUEEditorialNEXTJAFC on Future TrackThomas F. Hofmann*Thomas F. Hofmann*[email protected]More by Thomas F. Hofmannhttps://orcid.org/0000-0003-4057-7165Cite this: J. Agric. Food Chem. 2024, 72, 1, 1–3Publication Date (Web):January 10, 2024Publication History Received16 December 2023Published online10 January 2024Published inissue 10 January 2024https://pubs.acs.org/doi/10.1021/acs.jafc.3c09560https://doi.org/10.1021/acs.jafc.3c09560editorialACS PublicationsCopyright © 2024 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views609Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (8 MB) Get e-AlertscloseSUBJECTS:Carbohydrates,Food,Manufacturing,Pharmaceuticals,Plants Get e-Alerts

A sensitive high-performance liquid chromatography-triple quadrupole mass spectrometry (HPLC-MS/MSMRM) method, leveraging both technique and internal calibration, was developed for the simultaneous and comprehensive quantitative analysis of 46 antioxidants and antioxidant precursors in different beer types without any cleanup procedure. Combined with their in vitro antioxidant activity, a dose-activity estimation exposed a group of 10 key antioxidants, namely, tryptophan, tyrosine, hordatine A, hordatine B, procyanidin B3, prodelphinidin B3, tachioside (3-methoxy-4-hydroxyphenyl-beta-d-glucopyranoside), (+)-catechin, tyrosol, and ferulic acid. To study the effect of antioxidants in spiking and aging studies, another liquid chromatography-MS (LC-MS)-based method was developed, monitoring markers for oxidation in beer. A positive effect of the antioxidants on the flavor stability at naturally relevant concentrations was shown by a slowing of oxygen-dependent aging reactions highlighted in beer storage trials under oxygen atmosphere. Thereby, a doubling of the natural concentration of all investigated antioxidants in beer revealed a limit inhibition of 67% on the degradation of cis-isocohumulone to hydroxy-cis-alloisocohumulone.

The thesis provides a draft map of the chemical space of chemosensory active molecules in foods and enables, by application of cheminformatics approaches, the deduction of general principles of raw material influence and processing on the sensory perception of complex food systems. The summarized data supports the development of analytical methods targeting the efficient quantitation of key compounds, provides a database for screening of chemosensory receptor agonists and facilitates the optimization of in-silico tools for prediction of receptor activation determining sensory quality and biological function.

As a traditional Thai condiment, Pla-ra is used to add flavor and richness to dishes. Nine treatment combinations of Pla-ra formulations created from 3 types of fish (Mor fish, Kradee fish, and Mor + Kradee fish) and 4 different carbohydrate sources (none, rice bran, roasted rice, and rice bran-roasted rice mixture) were studied through a 12 month fermentation period (1, 3, 5, 7, 8, 9, 10, 11, and 12 months). 16S rRNA Next Generation Sequencing (NGS) and LC-MS/MS techniques were used to analyze the microbial diversity and identify taste-enhancing peptides. Descriptive sensory analysis was performed on the extracts of the 108 Pla-ra samples mixed in a model broth. Koku perception and saltiness-enhancing attributes were clearly perceived and dominant in all samples, even though glutamyl peptides, including gamma-Glu-Val-Gly, were found at subthreshold levels. The samples from mixed fish and Mor fish fermented with roasted ground rice and rice bran for 12 months had the most typical Pla-ra odors and tastes and had high taste-enhancing activities. NGS analysis revealed the presence of bacteria containing a large number of protease and aminopeptidase genes in the samples. Bacillus spp., Gallicola spp., and Proteiniclasticum spp. correlated well with the generation of glutamyl and arginyl peptides and typical odors in the samples. These results confirmed the typical sensory quality of Pla-ra depended on protein sources, carbohydrate sources, and bacteria communities. Further optimization of the microbial composition found could lead to the development of starter cultures to control and promote flavor development in fermented fish products.

Most circular processing pathways involve solid–fluid reactions, such as adsorption, catalysis, degradation, and extraction. The reaction-harboring plant technology is crucial to the performance and resource efficiency of these processes. Therefore, this study investigates the technoecological characteristics of the planetary rotating bed reactor (PRBR) as a novel approach to solid–fluid reactions. Given its relevance in wastewater treatment, the adsorption of methylene blue (MB) from aqueous solution onto powdered activated carbon (PAC) served as a model process. Semicontinuous kinetic experiments were performed in a 2 L laboratory-scale PRBR by varying the amount of PAC, the rotational motion pattern, and the speed level. DIY inline photometry and volume flow control enabled a constant vessel concentration of MB and thus the acquisition of comparable adsorption rates. Torque measurement delivered the mechanical power consumption and allowed calculation of the emission cost per adsorbate. The results revealed a significant superiority of the distinctive planetary motion compared to a static particle bed in terms of mass transfer and energy efficiency. The adsorption rate increased up to a factor of 10 with the same power input. Furthermore, an optimal chamber filling was observed, reflecting the interplay between the particle mobility and available adsorption sites.