Identification of 4'-Demethyl-3,9-dihydroeucomin as a Bitter-Masking Compound from the Resin of .

Masking the bitter taste of foods is one of the key strategies to improve their taste and palatability, particularly in the context of clean labeling, where natural compounds are preferred. Despite the demand, the availability of natural bitter-masking compounds remains limited. Here, we identified the bitter-masking compound 4'-demethyl-3,9-dihydroeucomin () isolated from the resin of by means of an activity-guided in vivo (sensory bitterness rating of quinine) and in vitro (cell-based bitter response assays) approach.

Investigating the Role of Odorant-Polymer Interactions in the Aroma Perception of Red Wine: A Density Functional Theory-Based Approach.

The aroma of red wine results from the intricate interplay between aroma compounds (odorants) and complex polymers generated during fermentation. This study combines density functional theory (DFT), human sensory experiments, and nuclear magnetic resonance to investigate the impact of odorant-polymer interactions on wine aroma. Molecular aggregation patterns of odorants with polymer segments are identified, indicating the crucial role of intermolecular noncovalent interactions, such as hydrogen bonds and van der Waals interactions, in stabilizing odorant-polymer conformations.

The multi-faceted food odorant 4-methylphenol selectively activates evolutionary conserved receptor OR9Q2.

4-Methylphenol is a food-related odor-active volatile with a high recognition factor, due to its horse stable-like, fecal odor quality. Its ambivalent hedonic impact as key aroma compound, malodor, and semiochemical has spurred the search for its cognate, chemosensory odorant receptors across species. A human odorant receptor for the highly characteristic 4-methylphenol has been elusive.

Modeling the Orthosteric Binding Site of the G Protein-Coupled Odorant Receptor OR5K1.

With approximately 400 encoding genes in humans, odorant receptors (ORs) are the largest subfamily of class A G protein-coupled receptors (GPCRs). Despite its high relevance and representation, the odorant-GPCRome is structurally poorly characterized: no experimental structures are available, and the low sequence identity of ORs to experimentally solved GPCRs is a significant challenge for their modeling. Moreover, the receptive range of most ORs is unknown.

Sensomics-Assisted Aroma Decoding of Pea Protein Isolates ( L.).

The aroma of pea protein ( L.) was decrypted for knowledge-based flavor optimization of new food products containing pea protein. Sensomics helped to determine several volatiles via ultra-high performance liquid chromatography tandem mass spectrometry and 3-nitrophenylhydrazine derivatization.

Sensomics-Assisted Flavor Decoding of Dairy Model Systems and Flavor Reconstitution Experiments.

The whole sensometabolome of a typical dairy milk dessert was decoded to potentially serve as a blueprint for further flavor optimization steps of functional fat-reduced food. By applying the sensomics approach, a wide range of different dairy volatiles, semi and nonvolatiles, were analyzed by ultrahigh-performance liquid chromatography tandem mass spectrometry with or without derivatization presteps. While for volatile sulfur compounds with low odor thresholds, headspace solid-phase microextraction gas chromatography was established, abundant carbohydrates and organic acids were quantified by quantitative H nuclear magnetic resonance spectroscopy.

Enantioselective synthesis of tri-deuterated (-)-geosmin to be used as internal standard in quantitation assays.

For the accurate and sensitive quantitation of the off-flavor compound geosmin, particularly in complex matrices, a stable isotopologue as internal standard is highly advantageous. In this work, we present a versatile synthetic strategy leading from (4aR)-1,4a-dimethyl-4,4a,5,6,7,8-hexahydronaphthalen-2(3H)-one to tri-deuterated (-)-geosmin ((4S,4aS,8aR)-4,8a-dimethyl(3,3,4- H )octahydronaphthalen-4a(2H)-ol). The starting material was readily accessible from inexpensive 2-methylcyclohexan-1-one using previously published procedures.

Structure/Odor Activity Studies on Aromatic Mercaptans and Their Cyclohexane Analogues Synthesized by Changing the Structural Motifs of Naturally Occurring Phenyl Alkanethiols.

Following a structure/odor activity approach as previously published, the present study was focused on three aromatic thiols also identified as food odorants, namely 1-phenylethane-1-thiol, phenyl methanethiol, and 2-phenylethanethiol. Their structures were systematically modified to receive 16 new sulfur-containing benzene derivatives. A determination of odor thresholds indicated that none of its homologues elicited a lower odor threshold than 1-phenylethane-1-thiol, and an enantiospecific synthesis, elucidated that its ( S)-enantiomer turned out to be the compound with by far the lowest odor threshold of 0.

Characterization of Aroma-Active Compounds in Italian Tomatoes with Emphasis on New Odorants.

An aroma distillate was prepared by solvent extraction and subsequent SAFE distillation from Italian vine-ripe tomatoes eliciting an intense overall aroma. Application of gc/olfactometry and the aroma extract dilution analysis revealed 44 odor-active compounds, 42 of which could be identified. The highest odor activity value of 2048 was established for the green, grassy (Z)-3-hexenal, the metallic smelling trans-4,5-epoxy-(E)-2-decenal, the potato-like 3-(methylthio)propanal, and the caramel-like 4-hydroxy-2,5-dimethyl-3(2H)-furanone.

The Broadly Tuned Odorant Receptor OR1A1 is Highly Selective for 3-Methyl-2,4-nonanedione, a Key Food Odorant in Aged Wines, Tea, and Other Foods.

Key food odorants are the most relevant determinants by which we detect, recognize, and hedonically evaluate the aroma of foods and beverages. Odorants are detected by our chemical sense of olfaction, comprising a set of approximately 400 different odorant receptor types. However, the specific receptor activity patterns representing the aroma percepts of foods or beverages, as well as the key food odorant agonist profiles of single-odorant receptors, are largely unknown.

Accurate determination of reference materials and natural isolates by means of quantitative (1)h NMR spectroscopy.

A fast and precise proton nuclear magnetic resonance (qHNMR) method for the quantitative determination of low molecular weight target molecules in reference materials and natural isolates has been validated using ERETIC 2 (Electronic REference To access In vivo Concentrations) based on the PULCON (PULse length based CONcentration determination) methodology and compared to the gravimetric results. Using an Avance III NMR spectrometer (400 MHz) equipped with a broad band observe (BBO) probe, the qHNMR method was validated by determining its linearity, range, precision, and accuracy as well as robustness and limit of quantitation. The linearity of the method was assessed by measuring samples of l-tyrosine, caffeine, or benzoic acid in a concentration range between 0.

Quantitation of S-methylmethionine in raw vegetables and green malt by a stable isotope dilution assay using LC-MS/MS: comparison with dimethyl sulfide formation after heat treatment.

The potent odorant dimethyl sulfide (1), showing a low odor threshold of 0.12 microg/L in water, is known to contribute to the aromas of various foods. Its cabbage-like odor plays an important role, particularly, in cooked vegetables, such as cabbage, celery, or asparagus.