A sensory characterization of some N‐heterocycles in model spirit matrix: Influence of ethanol and several chemical features on aroma perception

Abstract

The qualitative spirit ageing bouquet, developed during maturation in oak casks through a complex transformation process, can result in a broad palette of nuances where roasted and nutty aromas are often identified. Nitrogen heterocycles (pyrazines, thiazoles, pyrroles), produced during the heating step of the barrel‐manufacturing, contribute to the perception of these nuances. However, their specific sensory characteristics within the spirit matrix have been poorly studied until now. The current study consisted in an overall olfactory characterization of nine targeted N‐heterocycles molecules previously identified in oak wood and detected in spirits. In a first step, the olfactory perception thresholds (detection and recognition) were measured in a spirit model medium (23% hydroalcoholic solution, pH 4), revealing that the presence of ethanol at such level minimally affected the olfactory perception of the studied compounds. A first sensory description of the set of N‐heterocycles also highlighted a large spectrum of aromatic nuances, mostly related to the semantic field of wood (nut, roasted, smoky, spicy). In a second step, a profile of the key aromatic attributes of the studied molecules was compiled, on the basis of their corresponding intensity scores given by a trained expert panel. Principal Component Analysis followed by Hierarchical Cluster Analysis categorized the pool of N‐heterocycles according to their sensory similarities. The presence of ethanol in spirit model matrix did not affect detection and recognition thresholds of studied N‐heterocycles. Wood‐derived nuances accounted among the most representative aromas characterized the studied N‐heterocycles. Functionals groups carried out by the chemical ring modified the aromatic perception of N‐heterocycles.

Retronasal sensory characterization of aroma compounds in Baijiu by detection threshold measurement, retronasal OAVs, and time‐intensity evaluation

“…2‐Methyl‐3‐(methyldisulfanyl)furan imparted a roasted meat aroma, and furfuryl methyl disulfide had a roast odor. Among the four pyrazines studied, RDTs were continuously decreased with the increasing number of alkyl substituents attached to the ring, which was consistent with the result that both odor detection and recognition threshold values decreased in a spirit model medium (Goullet et al., 2023). Quantitative structure–activity relationship models of pyrazine‐based aroma compounds suggested a conformational and steric effect on the interaction with active sites of olfactory receptors (Buchbauer et al., 2000; Pal et al., 2013).…”

Design, synthesis, olfactory evaluation and molecular docking study of Isoxazoline carboxylate derivatives as fragrance molecules

“…Heterocyclic compounds have vital importance in synthetic organic chemistry due to their roles in many naturally occurring molecules, as well as their crucial significance in the fields of pharmaceuticals and cosmetic industries 1,2 . These compounds mostly contain oxygen, sulphur and nitrogen atoms in their structures and are found in food flavours and fragrances, possessing valuable organoleptic characteristics 3,4 . Among these heterocycles, isoxazoline seems to be an attractive option since limited studies have been reported regarding their odour characteristics so far 5 .…”

“…1,2 These compounds mostly contain oxygen, sulphur and nitrogen atoms in their structures and are found in food flavours and fragrances, possessing valuable organoleptic characteristics. 3,4 Among these heterocycles, isoxazoline seems to be an attractive option since limited studies have been reported regarding their odour characteristics so far. 5 Therefore, the synthesis of new heterocycles having potential fragrant properties is highly desirable and challenging.Conventional 1,3-dipolar cycloaddition reactions are one of the best tools to provide heterocyclic molecules in a single synthetic step, and depending on the substituents of the starting materials, the regio-and/or stereochemistry of the products can be controlled.…”

“…1,2 These compounds mostly contain oxygen, sulphur and nitrogen atoms in their structures and are found in food flavours and fragrances, possessing valuable organoleptic characteristics. 3,4 Among these heterocycles, isoxazoline seems to be an attractive option since limited studies have been reported regarding their odour characteristics so far. 5 Therefore, the synthesis of new heterocycles having potential fragrant properties is highly desirable and challenging.…”

“…After evaporation of solvent under vacuum to give 141.9 g (0.85 mol) of 2e, 85%, with a GC cis/trans isomer ratio of 54/46. For the major isomer: 1 H NMR (400 MHz, CDCl 3 ) δ 7.45 (t, J = 6 4. Hz, 1H, C=NH), 5.23 (s, 2H, C=CH, mix of isomers), 2.45-2.27 (m, 4H, mix of For the major isomer: 1 H NMR (400 MHz, CDCl 3 ) δ 7.39 (d, J = 6.5 Hz, 1H, N=CH), 2.48-2.37 (m, 2H, mix of isomers), 2.01-1.75 (m, 10H, mix of isomers), 1.61-1.53 (m, 5H, mix of isomers), 1.48-1.36 (m, 7H, mix of isomers), 0.95 (s, 6H, CH 3 , mix of isomers), 0.94 (s, 6H, CH 3 , mix of isomers).…”