Flavour and Fragrance Journal最新文献

The aroma of fine matured spirits is typically complex, resulting from numerous reactions occurring during the production process and some developing during maturation in oak casks. The refreshing sensation brought by mint notes was often expected, even after years of maturation. The main challenge lies in achieving an aromatic balance characterised by the seamless integration of woody aromas while maintaining the initial distillate's freshness. The present study examines the sensory effects associated with the interactions between wood, mint and cold sensations in spirits. Nine spirit model solutions were prepared, representing different combinations of terpene ketones (imparting mint aroma) and wood compounds, each at three concentration levels. The quantitative composition of mint compounds simulated varying degrees of mintiness in the distillate (low, medium and high), while the concentrations of wood compounds mimicked three maturation periods (short, intermediate and long term) in wooden casks. Samples were sensorily analysed by discriminative (triangle test) and rate-all-that-apply (RATA) methodologies. An increase in woody intensity was notably perceived in samples with a low-mint profile and containing wood compounds associated with medium and long-term maturation. However, no significant sensory differences were observed in mint and cold perception between model solutions regardless of the simulated maturation conditions, indicating a limited influence of the studied wood compounds on the sensation of freshness in spirits due to competitive perceptual interactions with terpene ketones.

The intricate immunomodulatory mechanism underlying the onset and progression of chronic rhinosinusitis with nasal polyps (CRSwNP) in chronic sinusitis with nasal polyps remains poorly understood, particularly regarding the regulatory role of dendritic cells (DCs). MicroRNA has been identified as a modulator of DC function. Primary cells have a short time in vitro and their biological characteristics have not changed greatly which can better reflect the growth state of cells in the body, so as to obtain data closer to the physiological function in the body. Our research group has been engaged in the culture of human nasal epithelial progenitor cells (hNEPCs) for a long time, and in previous investigations, we observed downregulation of microRNA-124 (miR-124) in patients with chronic sinusitis and nasal polyps. Thus, our current study aims to elucidate the regulatory mechanism of DCs in chronic sinusitis with polyps by examining the impact of miR-124 on DCs in this context. To accomplish this, we took the nasal mucosa of CRSwNP patients and normal nasal mucosa of non-rhinitis patients for primary culture. We isolated exosomes from these cells for co-culture experiments with DCs. Flow cytometry analysis was employed to assess the maturation phenotypes (MHC II, CD80 and CD86), cell cycle and apoptosis levels of DCs. Furthermore, enzyme-linked immunosorbent assay was utilized to measure the levels of pro-inflammatory cytokines (IL-10, IL-12 and IL-23). The TLR4/NF-κB signalling pathway in co-cultured DCs was evaluated using the western blot assay. Through querying the Targetscan website, we predicted Rab27a as a target gene of miR-124, which was subsequently validated through double luciferase assay, flow cytometry and other experimental approaches. Our findings demonstrate that MiR-124 modulates the secretion of CRSwNP epithelial exosomes, thereby influencing DC function via its interaction with the target gene Rab27a. These results offer novel insights into potential therapeutic targets for the treatment of CRSwNP.

Plant-based meat is projected to address world-wide meat shortage and supply–demand imbalances, potentially promoting the growth of sustainable diet choices. Soybean is a key ingredient to produce this alternative food, but the off-flavours that naturally occur in soy can hinder its widespread acceptance among consumers. This review extensively elaborates on the primary compounds responsible for off-flavours, their formation mechanisms, and removal techniques. Lipoxygenase oxidation–reduction, oleosins removal, adjustment extrusion conditions, and β-cyclodextrin treatment were discussed. Fermentation mechanisms, solvent extraction, enzymes hydrolysis, flavouring, and controlling storage conditions were summarised. The most crucial, safe, and effective techniques were enzyme restriction, β-cyclodextrin treatment in conjugation with phospholipase A2, and modification of the extrusion condition. The reviews provide a systematic summary of the development and prevention methods for the undesirable flavour of soy protein isolate and soy-based meat products.

The flowers of selected Camellia yuhsienensis Hu specimens were studied at different stages of flowering to determine the volatile components of floral fragrance and how their concentrations changed during efflorescence. The mechanism of fragrance formation and release was also studied in order to provide a theoretical basis for the practical use of C. yuhsienensis Hu flowers. Headspace solid-phase microextraction (HS-SPME) was used to extract the natural floral volatile oils of C. yuhsienensis Hu at the different stages, and the floral fragrance components were analysed by gas chromatography–mass spectrometry (GC–MS). A total of 31, 59 and 55 compounds were detected at the budding, early-blooming and full-blooming stages respectively. These floral fragrance components included terpene alcohols, as well as other aromatic and aliphatic compounds, and the relative concentrations of the various compounds at different stages of flowering, were different, and those of fatty alcohols and terpene alcohols having higher relative contents at all stages. The main component at the budding stage of C. yuhsienensis Hu was ocimene, which has a grassy fragrance, accompanied by the scent of neroli oil, which gives it a refreshing, gentle and sweet, and explains why the floral fragrance of C. yuhsienensis Hu at the budding stage is extremely thin: the main component during the early-blooming stage was 3-carene. A higher percentage of 3-carene increased the sweetness of the scent, manifesting the typical fragrant characteristics of C. yuhsienensis Hu. The main identified compound at the full-blooming stage was α-farnesene, which has a delicate fragrance, accompanied by a balsamic aroma, similar to the scent of gardenia, which is consistent with the sensory characteristics of C. yuhsienensis Hu.

Molecular modelling suggests that citral, one of the main components of lemongrass, interacts with Kelch-like ECH-associated protein 1, which is involved in the transcription of the antioxidant enzyme haeme oxygenase (HO)-1. A citral treatment of the pheochromocytoma (PC)12D cell line, an in vitro model of neurons, up-regulated the expression of HO-1 (mRNA: 28.7 ± 22.6, protein: 3.3 ± 0.8). The inhalation of lemongrass or citral aroma by mice decreased HO-1 mRNA levels in the ventral striatum (VSt) (0.68 ± 0.14, 0.72 ± 0.18, respectively), but not in the lateral hypothalamus or ventral tegmental area, which play important roles in appetite. Dopamine levels, which positively correlated with HO-1 mRNA expression levels in PC12D, were decreased in the murine brain by the inhalation of citral (0.79 ± 0.23). This reduction was cancelled by an injection of 6-hydroxydopamine, a selective inducer of dopaminergic neuron degeneration, into the nucleus accumbens, which is involved in pleasure, in VSt. Mice displayed aversion behaviour to the odour of citral, but no changes in their body weight. However, the oral administration of citral increased HO-1 protein levels in the murine VSt (1.25 ± 0.16). Subjects completed a questionnaire on the aroma of lemongrass essential oil, which revealed that most found it to be pleasant and it did not affect their appetite. Collectively, the present results demonstrated that humans perceive the aroma of lemongrass differently from mice, indicating its utility as a vermin repellent and antioxidant food.

Considerable synthetic effort has been devoted to acid- or base-catalysed transesterification of alkyl salicylate with alcohol in order to synthesize salicylate esters efficiently. In this study, the transesterification of methyl salicylate with 12 different alcohols was carried out by the use of Zn dust as a catalyst. Depending on the alcohol used in the transesterification reaction, the completion of the reaction was within a range of 8–15 h at a temperature between 100 and 170°C. The use of Zn dust provided reusability and almost complete recovery with moderate to excellent yields (42%–97%). The structural elucidation of the products was performed using IR, ¹H NMR, ¹³C NMR and GC–MS data obtained from the Wiley GC/MS Library and the in-house “Parkim Fragrance House GC/MS Library.”

Fruit aroma of Japanese apricot is distinct, and the specific volatile compounds are not clearly known during fruit development and during post-harvest stage. This study therefore aimed to explore the volatile compounds present during these stages. The volatile compounds were analysed by headspace solid-phase microextraction and gas chromatography–mass spectrometry. OAV, PCA and electronic nose techniques were used to determine the characteristic aroma components. Enzyme-linked immunoassay (ELISA) was also applied to determine the activity of enzymes. The results showed that in the cultivars ‘Xiyeqing’ a total of 52 components that included 20 terpenes, 15 aldehydes, 9 esters, 3 ketones and 5 other substances were detected during fruit development and post-harvest stage. While in the cultivar ‘Xiaoyezhugan’ a total of 49 components that included 25 terpenes, 7 aldehydes, 11 esters, 1 alcohol, 3 ketones and 2 other substances were also detected during fruit development and post-harvest stage. We concluded that the characteristic volatile compounds of mature Japanese apricot fruit were (+)-limonene, linalool, damascenone, β-damascenone and nonanal, finding the basis for the fruity, floral and sweet aroma of the Japanese apricot fruit. Further analysis indicated that low temperature inhibited the synthesis of esters and terpenes, and dark conditions were more favourable to the synthesis of volatile compounds than light conditions. Short-term storage of Japanese apricot fruit at room temperature and dark conditions was conducive for the maintenance of volatile compounds, and low-temperature storage was the most destructive to the fruit volatile compounds. These findings form a theoretical foundation for exploring the specific volatile compound of Japanese apricot and helped to determine the optimal storage condition of post-harvest stage for Japanese apricot fruit.