Flavour and Fragrance Journal最新文献

In the current study, the lipophilic solvent (n-hexane) extraction, steam distillation (SD) and supercritical CO₂ fluid extraction (SC–CO₂) methods were used to extract the volatile components of Mentha asiatica Boriss. Comparisons were made between the extraction yield, chemical component and biological activity. Gas chromatography quadrupole-time-of-flight mass spectrometry (GC–QTOF–MS) and semi-quantitative analysis of chemical contents by flame ionization detector (GC–FID) were used to study the chemical ingredients in Mentha asiatica Boriss. aromatic extract. The oil extract obtained from lipophilic solvent (n-hexane) extraction (1.27 ± 0.03%, w/W) showed the highest yield, followed by supercritical CO₂ fluid extraction (1.15 ± 0.04%, w/W), the extraction rate of SD was (0.37 ± 0.01%，w/W). The oil extract of Mentha asiatica Boriss. contained a total of 70 components that were identified. In the following, the primary volatile compounds of the essential oil produced using the three extraction techniques: α-thujene, camphene, sabinene, β-pinene, β-cymene, limonene, β-terpinene, camphol, α-terpinene, carvenone, carvone, piperitone oxide, thymol, myrtenyl acetate, dihydrojasmone, caryophyllene, germacrene D and caryophyllene oxide. Findings from this study indicate that the three methods of essential oil extraction produced oils with varying antioxidant capacities against DPPH and ABTS free radicals. Against Staphylococcus aureus, Candida albicans, Bacillus subtilis and Escherichia coli, all of the essential oils simultaneously showed clear inhibitory actions. Response surface methodology (RSM) and the Box–Benhnken design with three factors and three levels were both utilized to optimize the distillation process of essential oils. The appropriate extraction parameters were a 3 h extraction period, a solid–liquid ratio of 1:10 and a 3 h soaking time. The highest yield of essential oil was 0.38%. The impact of extraction parameters on essential oil yield was examined using the SD method. The findings indicated that the main factors affecting the yield of volatile oil extracted by SD were soaking time > ratio of solid to liquid > extraction time.

Linalool is an important substance in the synthesis of fragrances owing to its unique aroma. However, the application of linalool is limited due to its low stability and rapid volatilization. Supramolecular inclusion technology plays an important role in improving the stability and volatility of fragrance and endows fragrance with excellent heat-controlled release properties. In this study, inclusion complexes were prepared with two acyclic cucurbit[n]urils (M1 and M2) to improve the thermal stability of linalool, their binding behaviours were investigated by NMR, XRD, FT-IR and Molecular Docking, confirming the formation of the host-guest inclusion complexes. The stoichiometry of inclusion complexes was 1:1 by Job's plot and the binding constant was determined by fluorescence titration. The TG and heat-controlled release experiment indicated that the inclusion complexes have higher thermal stability. This study provides a new idea and method for the development of linalool series spices.

Higher alcohols (phenylethyl alcohol and isoamyl alcohol), as the crucial aroma compounds, have been found to associate with the sensory properties of various alcoholic products. The Ehrlich and Harris pathways are the main pathways for yeast to produce phenylethyl alcohol and isoamyl alcohol during the brewing process of alcoholic products, whereas the specific changes of the Ehrlich and Harris pathways in Wickerhamomyces anomalus under ethanol stress are still unclear. In this study, W. anomalus NCU003 with a high capacity for aroma compound production was treated with ethanol stress at different concentrations (3%, v/v, 6%, v/v and 9%, v/v) to study the effects on the expression levels of genes and metabolite content in the Ehrlich and Harris pathways. The results found that ethanol stress inhibited the production of phenylethyl alcohol and isoamyl alcohol, and the content decreased with the increase of ethanol concentrations. In the meantime, the up-regulation of ARO1, CS, ARO8, Leu1, BAT2 and ilvs family genes in the Ehrlich and Harris pathways could lead to an increase in the synthesis of important precursor substances during the synthesis of phenylethyl alcohol and isoamyl alcohol. However, the significant down-regulation of ARO10, PDC, ADH1 and AHD2 genes was the main reason for the low production of phenylethyl alcohol and isoamyl alcohol. These results could provide a theoretical reference for the construction of genetic engineering strains of W. anomalus in the future so as to reasonably control the content of higher alcohols during the brewing process of alcoholic products.

It has been reported that a distinct ‘old person smell’ can develop with advancing age, however, this odour has not yet been sufficiently described in previous research. Sensory evaluation by a trained panel might be useful to describe alterations with age in body odour (BO). To evaluate the alterations and achieve first insights into the ‘old person smell’, this pilot study determined the odour profiles of BO samples from both a younger and an older age group with a trained panel. In addition, we aimed to assess whether the panellists can recognize the age group based on the smell of the BO samples. Eight younger (20–28 years) and eight older (80–83 years) participants sampled their BO by wearing a cotton T-shirt for one night. The samples were sensorially evaluated by a trained panel, including ratings of total intensity and pleasantness. Additionally, an age labelling task was performed as a forced-choice decision. Results revealed that the odour profiles of the BO samples were very similar for both age groups. Nevertheless, trained panellists were able to predict the age group with significantly higher accuracy (p = .042) than expected by chance (61% mean accuracy over all panellists). Furthermore, a linear support vector machine (SVM) classifier achieved an average accuracy of 69%. This finding indicates that the age of a person affects the BO, though it is not reflected in significantly distinct odour profiles.

Citral (3,7-dimethyl-2,6-octadienal), a mixture of geranial and neral (two stereoisomeric monoterpene aldehydes), is considered an important raw material in the fields of fragrance, pharmaceutical, food and cosmetic industries. It is a well-known biologically active compound present in various essential oils. A fast and reliable experimental method was developed and validated in order to quantify citral in essential oils using ¹H NMR spectroscopy (experiment time at the minute level). The quantitative procedure, using anisole as internal standard, showed a perfect linearity of measurements (R² = 0.9999), a very good accuracy (relative errors comprised between −1.9% and 0.3%) and an excellent precision (reproducibility 17.8 mg ± 1.0%). The procedure was also checked with three mixtures of weighted monoterpenes and the contents of citral, measured by GC and ¹H NMR, were absolutely comparable. Then, the method was successfully applied to measure the contents of citral in 10 commercially available essential oils. Among the investigated samples, citral varied from 2.9% (Zingiber officinalis) to 90.6% (Bakhousia citriodora).

This publication presents the collaborative work conducted in CEN/TC 347/WG4 ‘Fragrance and colophony’ working group to evaluate the robustness of a GC–MS analytical methodology to quantify the extended list of 57 fragrance allergens in ‘ready to inject’ samples. The intention of this group was to provide an updated and consensual standard for the quantification of the extended allergen list. The analytical approach was based on the similar methodology than the original one developed for the 26 allergens, using a universal GC–MS simple quadrupole instrument. A ring test was performed among the different end-user experiences of the CEN group to test the method on a representative fragrance matrix. Accuracy profile method was used to validate the analytical method within the 2–240 mg/kg concentration range. Thanks to the use of commercial standard mixes and dedicated automation of decisional tree for data treatment, 89% of tolerance intervals of targeted allergens were included into the acceptance limits in the whole 2–240 mg/kg concentration range. The objective of this article was to provide some complementary data to implement the NF EN 16274 standard in an analytical laboratory and to highlight the inherent difficulties linked to extended data treatment and complexity for the recovery of low concentration analytes and potential coelutions in a wide diversity of ready-to inject samples.

Odour analysis of coffee using low-cost and portable instruments in coffee shops, restaurants and bars is essential to keep the loyalty of coffee consumers. This paper aimed to analyse the performance of a gas sensor array for odour classification of brewed coffee. Five grams of ground coffee sample from five different brands was brewed in 80 mL of hot water at a temperature of 90°C. The gas sensor array then measured the sensor's response to the brewed coffee odour. The recorded data were analysed using a principal component analysis (PCA), a hierarchical cluster analysis (HCA) and a support vector machine (SVM). Solid-phase microextraction gas chromatography–mass spectrometry (SPME-GC-MS) was used to identify the five coffee samples' volatile organic compounds (VOCs). The visualisation of the PCA score plot shows that the gas sensor array efficiently classifies the brewed coffee based on different odours. The SVM classification using a polynomial kernel obtained an accuracy of 95.21% using training data sets and an accuracy of 96.94% using testing data sets. Meanwhile, for SVM classification using radial basis function kernel, the SVM obtained an accuracy of 100% for training data sets and 93.06% for testing data sets. The SPME-GC-MS analysis showed that the abundance of 2-furanmethanol; 2-methoxy-4-vinyl phenol; phenol, 4-ethyl-2-methoxy- and acetic acid contributed to the separation of the first and the second clusters in the principal components coordinate. Based on data analysis, the gas sensor showed high performance as a low-cost and portable instrument for odour analysis of coffee based on sensory technique.

To compare the changes of potent odorants (PO) in high-salt liquid-state fermentation soy sauce (HLFSS) after sterilization under 120°C for 15 s, the volatiles in HLFSS were isolated by solvent extraction combined with solvent-assisted flavour evaporation and were analysed by gas chromatography-mass spectrometry-olfactometry. A total of 40 odour-active compounds were identified, and their flavour dilution (FD) factors ranging from 1 to 4096 were determined by comparative aroma extract dilution analysis. Twenty-four compounds with FD factors ≥8 were quantitated by establishing standard curves, and the results showed that total concentrations of alcohols and phenols were almost unchanged, those of esters, acids and pyrazines decreased and those of aldehydes and ketones increased. Based on quantitative results and thresholds in water, odour activity values (OAVs) were calculated. Eighteen compounds with OAVs ≥1 were determined as PO in HLFSS. The number of POs did not change after sterilization, and OAVs of 10 POs remained unchanged or varied very little. The significant changes in the concentrations of methional, 5-ethyl-4-hydroxy-2-methyl-3(2H)-furanone, nonanal, ethyl 2-methylbutanoate, methionol, benzeneacetaldehyde, 4-hydroxy-2,5-dimethyl-3(2H)-furanone and 2-ethyl-3,5-dimethylpyrazine after sterilization caused the obvious variations of OAVs, which made cooked potato, caramel-like, fatty and floral notes in HLFSS change in different degrees. The results obtained have some reference value to produce SS.

Application of EOs in the food industry are wide-ranging from preservation to production of food packaging materials. As a flavouring agent, citrus oil is one of the most popular EO used in food and beverages with other EOs. For instance, there are many studies relating the volatile compounds of sweet orange and more than 200 components of sweet orange EOs have been described as ‘components of flavor’. Oxygenated derivatives, such as alcohols, ketones, aldehydes, esters and epoxides, provide preservative and flavour effects on food products but their levels are no more than 10% in citrus EOs generally. Therefore, deterpenation methods can be applied to EOs and oxygenated derivative concentrations would be increased. This study reviews primary oxyterpenes existing in citrus EOs, their use in the food industry, deterpenation methods applied to some types of citrus EOs and gives information about their main advantages and disadvantages. In conclusion, membrane separation techniques are proposed in order to purify citrus EOs on the basis of being environmentally friendly and not required any solvents both for separation.

Recently, there has been a growing interest in natural products of plant origin as herbal remedies. In this study, the profile of bioactive volatile organic compounds and odorous compounds in a sample of Pistacia lentiscus L. vegetable oil has been determined. The study indicated that the oil extraction yield is influenced by the method, the extraction conditions, the stage of maturity of plant and the sampling area. Analysis by HS-SPME-GC–MS and GC–MS showed that monoterpenes and sesquiterpenes represent the most numerous groups among the 57 compounds identified. The most abundant compounds are beta-myrcene, d-limonene and linoleic acid ethyl ester. Among other compounds humulene, caryophyllene, a-muurolene and copaene have been detected known for facilitating wound healing. Moreover, β-caryophyllene and α-humulene with anti-inflammatory effects have been determined. 38 different odorous compounds with herbal, citrus and vegetable aromas were detected by panellists using HS-SPME-GC-O-MS. Research confirmed that the analysed samples have only pleasant aromas that make it a perfect active agent for medicinal use and may gain acceptance of consumers.