Flavour and Fragrance Journal最新文献

The molecular architecture of odorants, nuanced by factors such as chirality and carbon chain length, significantly influences sensory perception. Despite this, the role of double bond isomerization in olfactory evaluation remains underexplored. This study delves into how the double-bond rearrangement in damascone impacts flavour perception, combining sensory evaluation and computational simulation. Sensory results showed that α- and δ-damascone had more pronounced minty notes, while β-and δ-damascone exhibited more significant floral ones. Notably, the odour thresholds determined via the S-curve method were 0.0145 μg/mL, 0.0373 μg/mL and 0.0011 μg/mL for α-, β- and δ-isomers, respectively, indicating a significant difference in potency. To further investigate the influence of double bond rearrangement on receptor binding, molecular docking and molecular dynamic simulations were utilised. Molecular docking revealed that δ-damascone had the lowest binding energy, correlating with its high potency, and identified key interactions with residues such as TYR-262 and TYR-251. Molecular dynamics simulations further demonstrated that double bond isomerization affected the binding stability between the three damascones and olfactory receptors, as evidenced by root-mean-square deviation (RMSD) fluctuations, with α- and δ-damascone forming more stable complexes. Together, these results provide a mechanistic understanding of how double bond configuration dictates damascone odour perception through distinct receptor binding modes.

For Ponkan mandarin, a highly popular citrus fruit, the maintenance and improvement of its aroma are of practical interest, but the formation and transformations of its aroma compounds, especially terpenoids, are still not well understood. This work investigated the key free volatile terpenoids in ripe Ponkan mandarin pulp (PMP) during shelf life, quantifying their dynamic changes and examining their formation and transformation mechanisms to elucidate the underlying metabolic pathways. Fifteen free volatile terpenoids were identified from PMP. Three terpenoids were found in PMP for the first time, that is, 1,4-dimethyl-4-acetyl-1-cyclohexene, 6-camphenone and nootkatone. The contents of linalool, α-terpineol, citronellol and (E)-nerol decreased steadily over time, whereas the contents of D-limonene, 6-camphenone, trans-carveol, carvone and β-damascenone were the highest after storage for 1 week. The following interconversions between the aroma terpenoids in PMP were confirmed: D-limonene, from linalool, terpinen-4-ol, α-terpineol, carveol, citronellol, L-carvone, (Z)-nerol, piperitone and L-perillal; α-terpineol, from linalool, (Z)-nerol and D-limonene; linalool, from citronellol, (Z)-nerol and α-terpineol; (E)-nerol, from linalool; terpinen-4-ol, from L-perillal, citronellol and α-terpineol; piperitone, from terpinen-4-ol; carveol, from D-limonene; carvone, from carveol. The formation and transformation of these terpenoids mainly involved the rearrangements of carbocations and the redox reactions of intermediates.

Kezixiang agarwood essential oil is the luxury aromatic product widely used in high-end perfumery. Aroma quality, as one of the most critical determinants of Kezixiang agarwood essential oil, exhibits significant variations depending on extraction methods, though these differences remain poorly characterised. This study employed comprehensive analytical strategies using GC × GC–TOF–MS and GC–O–MS to elucidate the aroma profiles of Kezixiang agarwood essential oil obtained through steam distillation (SDAO) and supercritical carbon dioxide extraction (SCAO). GC × GC–TOF–MS analysis identified 240 volatile compounds, predominantly sesquiterpenes and their oxygenated derivatives. GC–O–MS detected 58 aroma-active compounds (54 in SDAO, 32 in SCAO), contributing to 11 sensory attributes: woody, cool, herbal, bitter, spicy, sweet, sour, floral, fruity, creamy and fatty notes. Their flavour dilution (FD) factors ranged from 3 to 19,683. Eighteen compounds exhibited FD factors ≥ 27, with benzylacetone, aromadendrene epoxide, coumarin, (E)-2-nonenal, nonanol, 9-cedranone, anisicaldehyde and eudesma-3,11-dien-2-one demonstrating FD factors exceeding 100. Notably, SDAO displayed higher FD values than SCAO in most cases. SDAO exhibited an intense woody aroma with pronounced herbal and bitter notes, whereas SCAO presented a milder profile dominated by creamy and sweet nuances. These distinct sensory characteristics were strongly correlated with the type and content of the key odorants. This study provides the molecular-level characterisation of aroma differentiation between SDAO and SCAO, establishing a scientific foundation for targeted optimisation of agarwood essential oil production.

This study examines the effects of four different types of brewing water, including purified water (PW), natural water (NW), natural mineral water (NMW) and electrolysed water obtained (EW) on the release of aroma compounds in green tea infusions through consumer-based sensory evaluation Rate-All-That-Apply (RATA) and GC–MS analysis. The research results indicated that tea infusions brewed with PW at pH 7.13 contain the highest levels of volatile compounds (527.84 μg/kg), tea polyphenols (18.83%) and soluble sugars (9.20%). In contrast, those brewed with alkaline EW at pH 9.15 exhibited the lowest levels. The RATA results indicated that consumers can distinctly perceive differences between tea infusions prepared with different brewing water. Tea infusions prepared with NW at pH 7.71 were the most preferred. The floral and chestnut aromas of the tea infusions were initially higher as the pH of the brewing water increased, followed by a decline, while the tend aroma weakened and the dull odour increased. The bitterness and astringency were more prominent in tea infusions prepared using NMW and EW. Partial least squares regression (PLSR) analysis identified α-terpineol, decanal, nonanoic acid, benzophenone, nonanal and 1-tetradecanol as key contributors to ‘flowery aroma’ and ‘chestnut aroma,’ with higher concentrations of these compounds correlating with increased consumers' preference for tea infusions. These substances were abundant in tea infusions prepared with PW and NW. Additionally, an analysis of the effect of different concentrations of SiO₃²⁻ in aqueous solutions on green tea infusion flavour indicated that SiO₃²⁻ promotes the release of alcoholic compounds in tea infusions, thereby improving the overall fragrance of the tea. The tea infusions T1 and T2, prepared using PW and NW respectively, demonstrated superior consumer acceptability due to their well-balanced flavour profile and harmonious taste characteristics, making PW and NW particularly suitable for green tea preparation. These results provide valuable insights into the effects of different brewing water types on green tea's flavour quality.

Homalomena aromatica is an economically important essential oil-producing plant. The rhizome is a commercial source of essential oil useful for high-grade perfumery and therapeutic applications. It is mainly collected from wild sources. The present study aims to investigate the histochemical localization of oil-secreting idioblasts and the variability in oil composition in commercial samples. The histochemical study revealed that essential oil is synthesised in oil cells and oil cavities distributed in the rhizome tissues. The larger oil cavities (521 ± 59.4 μm in size) synthesise essential oil and resin, whereas the smaller oil cells (67.2 ± 7.4 μm in size) synthesise only essential oil. The spatial distribution demonstrates that the oil cavities were densely present in the inner ground tissue region, whereas the oil cells were abundant in the cortex (p < 0.05). The different grades of commercial rhizome samples, that is, thickness up to 10 mm (narrow rhizomes, NR), 10 to 20 mm (medium-sized rhizomes, MR), and 20 to 30 mm (thick rhizomes, TR) showed variation in essential oil yield and composition, fibre content, and distribution of fibre cells. The study demonstrated that the oil yield is negatively correlated with rhizome thickness, fibre content, and density of fibre cells in tissue. The oil of H. aromatica is dominated by linalool (44.18%–61.4%) followed by terpinene-4-ol (6.45%–13.16%) in the rhizomes of different thicknesses. These major constituents also negatively correlate with rhizome thickness and significantly decrease in the TR samples. The study concludes that the NR grade rhizomes are better for higher oil yield and linalool and terpinene-4-ol content than the TR grade of H. aromatica rhizomes.

Despite the widespread use of eucalyptus leaves in pharmaceutical and food industries, optimising their drying process to preserve bioactive compounds while minimising energy consumption remains a critical challenge. This study systematically investigates the drying of eucalyptus leaves using convective, infrared and combined convective–infrared dryers under varying temperatures (40°C–60°C), air velocities (0.5–1.5 m/s) and infrared powers (700–1500 W), with experiments designed via response surface methodology (RSM) based on a central composite design (CCD). Results revealed that increasing temperature, air velocity and infrared power simultaneously reduced drying time (t) and energy consumption (E), while total phenolic compounds (TPC) and antioxidant activity (DPPH) initially increased to a peak before declining. Optimal conditions were identified as 53°C and 1.2 m/s (convective), 1397 W (infrared) and 48°C, 0.7 m/s and 1137 W (combined), achieving balanced outcomes for t, E, TPC and DPPH. These findings provide actionable insights for industrial-scale drying processes, ensuring energy efficiency and maximal retention of bioactive compounds. Future research could explore hybrid drying techniques or scalability to other medicinal plants.

Fritillaria michailovskyi Fomin, an endemic bulbous species, is a promising medicinal plant due to its secondary metabolites, attracting interest for its potential neuroprotective properties and volatile compound composition. This study aims to determine the anticholinesterase effects of cultivated forms of Fritillaria michailovskyi (yellow lip, Liliaceae), an endemic species of our country, collected in November 2019 and July 2020, and identify the volatile compound(s) using solid-phase microextraction (SPME) technique and analysed by GC–MS. Extracts of F. michailovskyi were prepared from bulbs of cultivated forms collected in November 2019 and July 2020 using solvents with varying polarities (methanol, ethyl acetate, dichloromethane). The in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory effects of these extracts were assessed. The volatile compounds were trapped with solid-phase microextraction (SPME) technique in plant samples and analysed by GC–MS. Comparative GC–MS analysis of the plant samples from 2019 and 2020 revealed that aliphatic hydrocarbons and their methyl and dimethyl derivatives were the dominant components, with total volatile compound contents of 57.3% and 59.8%, respectively, and dodecane was identified as the most abundant compound in both samples. The AChE and BChE inhibition assays revealed that the most effective extract was the ethyl acetate extract obtained from bulbs collected in 2019. The findings suggest that the ethyl acetate extract of F. michailovskyi, particularly from the November 2019 collection, may serve as a potential source for further studies as a potential therapeutic agent in the treatment of Alzheimer's disease.

Chrysanthemum indicum var. aromaticum (Ci. var. aromaticum) is a rare alpine aromatic plant with the potential to be used as a natural perfume due to its high-value essential oil content. However, the lack of data on the effects of climate parameters, especially temperature, on its aroma profile has limited its large-scale cultivation. In this study, the effect of ambient temperature (10°C, 15°C, 20°C, and 25°C) on the aroma profile of Ci. var. aromaticum was systematically investigated using a static headspace solid-phase microextraction coupled with chromatography-mass spectrometry (HS-SPME-GC–MS) approach. The results showed that 20°C was favourable for the accumulation of volatile compounds (reaching 984.799 μg/g in flowers and 1802.368 μg/g in leaves), among which terpenes dominated the composition of aroma components, reaching 847.607 μg/g in flowers and 1689.583 μg/g in leaves. Additionally, 20°C was also conducive to the accumulation of esters and alcohols, while the unique substances in flowers and leaves were different at different temperatures, indicating that temperature had a greater regulatory effect on the types of volatile compounds. In conclusion, the growing condition of 20°C was favourable for the accumulation of volatile/aroma compounds in Ci. var. aromaticum, which may provide data support for the introduction, domestication, and aroma quality detection and control of Ci. var. aromaticum as a natural perfume.