Flavour and Fragrance Journal最新文献

Magnolia biondii flower buds are a well-known medicinal plant in China, and it is important to determine the differences in aroma, flavour components, and biological activity of the essential oils of M. biondii flower buds (EOM) from different origins. In this study, the essential oils of M. biondii flower buds from Sichuan (EOM-SC), Anhui (EOM-AH) and Henan (EOM-HN) provinces were extracted by hydrodistillation. The condition of the extraction process was optimized. The differences in the flavour compounds were further confirmed by GC–MS and relative odour activity value (ROAV) analyses. In addition, the antibacterial and antioxidant activity was also evaluated. The results showed that the optimized condition for steam distillation was water: flower powder ratio = 10:1 with extraction time for more than 3.0 h. Interestingly, special floral, fruity and freshness flavours were found for EOM-SC, and the medicinal herb and sweetness odours of EOM-HN were more prominent. The numbers and contents of flavour compounds in EOM-SC and EOM-HN were higher than those of EOM-AH. Eucalyptol, β-pinene, linalool, α-terpineol and sabinene could be proposed as the key mutual flavour compounds for three essential oils. In addition, the strong floral, fruity and freshness aroma of EOM-SC could be associated with the high ROAVs of α-terpineol, linalool and sabinene. Moreover, EOM-SC exhibited better antibacterial and antioxidant activity than those of the other two essential oils.

The objective of this study was to screen non-Saccharomyces yeast suitable for enhancing the aroma of Yinhong plum wine. Five non-Saccharomyces yeasts with strong ester-producing ability, namely, Wa3 (Wickerhamomyces anomalus), Hu12 (Hanseniaspora uvarum), Pk2A2, PkW2 and PkY2 (Pichia kluyveri), were selected from various naturally fermented fruit juices for molecular biological identification, analyses of physiological characteristics and tolerance and determination of their effects on the flavour of Yinhong plum wine. Analysis of brewing characteristics showed that they differed in their abilities of producing acetic acid, hydrogen sulfide, killer activity and tolerance. Among them, Wa3 showed the best tolerance to high concentrations of alcohol, sugar and SO₂. Compared to the control Saccharomyces cerevisiae FX10, Yinhong plum wine fermented with non-Saccharomyces yeast exhibited a decrease in alcohol content, while residual sugar, glycerol content and the types and quantities of volatile compounds all showed an increase. Among the fermented wines, PkY2 generated the highest content of ester compounds in the fermented wine, which was 5.66 times higher than that generated by the control. The compounds produced by PkY2 were closely related to various ethyl and acetate odour-active compounds (odour-active value >1), which could impart a rich floral and fruity aroma to Yinhong plum wine. Sensory analysis revealed that both floral and fruity aromas were significantly increased in Yinhong plum wine fermented by non-Saccharomyces yeasts, with the highest scores of floral and fruity aromas for PkY2. In conclusion, a Pichia kluyveri strain, PkY2, with excellent brewing characteristics and potential for enhancing the aroma of Yinhong plum wine was identified.

The Persian silk tree (Albizia julibrissin) has delicate flowers with a pleasant aroma profile, displaying notes of hyacinth and rose with subtle nuances of citrus, coconut and spice. In this study, a total of 29 odorants were identified in the flowers from a single A. julibrissin selection by the application of a cold-solvent extraction (CSE), followed by solvent-assisted flavour evaporation (SAFE) and aroma extract dilution analysis (AEDA). Subsequently, nine odorants with flavour dilution (FD) factors ≥16 were quantitated by stable isotope dilution analysis (SIDA), and odour activity values (OAVs) were calculated. Odorants with OAV ≥1 included 2-phenylacetaldehyde (OAV 3638), linalool (OAV 797), eugenol (OAV 231), geraniol (OAV 161), 1H-indole (OAV 93), β-ionone (OAV 31), 2-phenylethanol (OAV 11) and γ-octalactone (OAV 1). An aroma simulation model was prepared based on the quantitation data, and it closely matched the aroma of the flower isolate. Chiral chromatography was performed, and (S)-(+)-linalool was the only enantiomer detected. This study advances our understanding of A. julibrissin flower aroma chemistry and lays the groundwork for future investigations for the development of delicate floral aromas for flavour and fragrance applications.

Sleep disorders are widespread. Inhaled aromatherapy has shown advantages over medication in treating insomnia. Daylily (Hemerocallis fulva) has been found to positively affect sleep either by ingestion or inhalation, but there is a lack of research on the sleep aid effect of its inhalation route. At present, the floral scent characteristics of daylily are not obvious, and the extraction rate of essential oil is low. Based on the above problems, this study developed daylily essence which replicates the natural aroma of plants and investigated the effect of inhaling daylily essence aroma on sleep activity by using Pittsburgh Sleep Quality Index (PSQI) and electroencephalogram (EEG). According to PSQI results, inhaling the aroma of daylily essence improved participants' subjective sleep quality. The difference between men and women was statistically significant (p < .05). The slow-wave sleep activity of EEG in the experimental group was significantly stronger than that in the control group (p < .01). In addition, the frontal and central regions were more responsive to aroma stimuli (p < .05). The results of this study show that the aroma of daylily can promote the subjective and objective sleep quality of healthy college students, and the use of fragrance intervention is a potential scheme to improve sleep quality and insomnia.

This study investigates the impact of baking conditions and initial concentrations of flavourings on the evolution of three key flavourings (benzaldehyde, butyl butyryl lactate, and vanillin) in cookies during baking and subsequent storage. Controlled baking experiments were conducted at two temperatures (130°C and 160°C) with varying initial flavouring concentrations. The results reveal that baking at the higher temperature (160°C) led to a substantial loss of benzaldehyde and butyl butyryl lactate, resulting in a significantly lower proportion of these compounds in the final product compared to baking at 130°C. In contrast, vanillin showed greater stability at the higher temperature, with its proportion in the final product remaining stable or increasing compared to the lower temperature. Specifically, the proportion of benzaldehyde decreased from 18.33% in the dough to 4.31% after 2 weeks of storage for cookies baked at 160°C, whereas the proportion of vanillin increased from 47.24% to 61.38% in the same period. Statistical analysis, employing ANOVA and Tukey–Kramer HSD tests, confirmed the significant effect of baking temperature on the evolution of flavour compounds (p < 0.05). These analyses further revealed the notable influence of initial flavouring concentrations on the changes in benzaldehyde across all tested temperatures, as well as on butyl butyryl lactate and vanillin specifically at 130°C. These results offer valuable insights on how the baking process can be optimized to enhance the sensory profile of cookies and highlight the importance of temperature control and initial flavouring mix design.

Phenylacetaldehyde (PhA) is an aromatic aldehyde which has a hyacinth-like floral, sweet and green-leafy odour. PhA is used as a perfumery chemical and a rate-controlling additive in cosmeceutical and polymer industries, respectively. The conventional process of PhA manufacturing in industries involve hazardous and costly feedstock and often lead to generation of substantial amount of waste. Moreover, usage of stoichiometric reagents often makes the processes economically impractical. This article illustrates the possibility of production of PhA from low-cost feedstock styrene through a single-step, one-pot method wherein various metal oxides have been utilized as catalysts for styrene oxidation under the influence of cumene hydroperoxide (CHP). Ag₂O is found to be the highest PhA-yielding catalyst and a promising candidate for scaling up for its considerably good reusability up to 6 consecutive uses. A maximum of ~45% PhA selectivity has been observed at ~60% styrene conversion. Interestingly, this process does not require any alkaline/acid wash and hence does not produce any organic/inorganic liquid effluent stream. Furthermore, all the major byproducts found, that is styrene oxide, benzaldehyde and acetophenone, are themselves considered as valorized styrene derivatives. Overall, the metal oxide catalysed styrene oxidation has potential to take over the conventional industrial process(es) for sustainable selective production of PhA Along with a plausible mechanism of styrene oxidation over Ag₂O, a conceptualized reaction–separation framework has been reported for intensified production of PhA from CHP-based styrene oxidation.

In this research, a wide range of aldoxime derivatives with aromatic and aliphatic substituents were synthesized as precursors to nitrile oxide in cycloaddition reactions. The aldoximes were synthesized with good to high yields and showed a lack of diastereoselectivity, as confirmed by ¹H NMR measurements. These aldoximes were then utilized as precursors of nitrile oxide in 1,3-dipolar cycloaddition reactions and were treated with dipolarophilic reagents, namely methyl methacrylate (MMA) and glycidyl methacrylate (GMA), to produce isoxazoline carboxylate derivatives with high regioselectivity. The obtained compounds were characterized using various techniques, including NMR, FT-IR, GC–MS and TOF-LCMS analyses. The study also targets the molecular docking analysis, using Autodock 4.2.6 software, targeting the OR51E2 protein. This protein has drawn recent attention, with the hypothesis that propionic acid activates OR51E2, making it a suitable candidate for the carboxylate group within the obtained isoxazoline skeleton. Through these multifaceted investigations, this research contributes to the design and development of fragrant molecules with potential applications in the fragrance industry, offering a promising avenue for future olfactory innovations.

Damascus rose (DR) is an important economic crop. In recent years, DR has been widely planted and utilized in China. In order to improve its aroma quality, the volatile releasing regularities of DR need to be studied. Therefore, HS-GC-IMS were used to examine the style of aroma release in DR under three flowering states: pre-bloom (PB), half-bloom (HB) and full bloom (FB). The results show that HS-GC-IMS detected 56 volatile compounds to investigate the changes of volatile compounds in three states of DR during the growth period. The results of PCA showed that changes in aroma substances were obvious during the growth stage of DR. In addition, FB contributed some key aroma molecules of DR. Thus, volatiles in DR at different times of a day (5 AM, 11 AM, 5 PM) and were further examined by using P&T-GC–MS towards FB. Finally, a total of 68 volatile compounds were identified; most of them were terpenoids (47.83%–59.62%). Totally 21 volatiles were considered key compounds due to their high concentration (≥1%). These key compounds showed the highest levels at 5 AM and lowest levels at 5 PM. Heat map clustering showed that most of the key compounds possessing higher levels in the flowers had maximum levels at 5 AM and compounds with lower levels peaked at 11 AM. This study will provide a theoretical understanding of the aroma generation mechanism of DR. It also helps the rose farmers to plant and sow rose flowers practically.

Spiny coriander (Eryngium foetidum L.) is a traditional food flavouring herb of tropics with coriander-like odour. This study evaluated six different drying conditions (sun, shade, oven at 40°C and 60°C, microwave, freeze-drying) for spiny coriander leaves, emphasizing on the drying time, essential oil yield and composition. Fatty aldehydes, especially trans-2-dodecenal, majorly abundant key aromatic flavour of spiny coriander underwent probable enzymatic reduction to alcohols upon long-term oven-drying, affecting the oil quality. Non-conventional techniques like microwave and freeze-drying, despite their certain advantages significantly reduced the oil yield (0.030%–0.031%) in comparison to fresh leaves (0.045%). Sun drying was found to be superior among the tested conditions, considering a reasonable drying time (4 h) and ability to retain the oil yield (0.043%), composition (quality) and chlorophyll content. It can be a sustainable drying technique for spiny coriander in the tropical region with abundant sunlight, especially for its value addition and commercialization in future.

Spray drying is a process that involves instantaneous conversion of a liquid or slurry into a free-flowing powder in the presence of hot air or nitrogen gas current in a drying chamber. The technique is usually used to encapsulate active molecules like essential oils, plant extracts, fragrances, flavours and enzymes within a wall material. The encapsulation provides chemical and physical stability to the actives by converting them into free-flowing powders which prevents their susceptibility to external atmospheric conditions like temperature, humidity, UV exposure and chemical oxidation. Spray drying encapsulation has an edge over other encapsulation techniques because it is fast, simple, efficient and economically feasible. The article focuses on encapsulating various essential oils within natural polymers and emulsifiers by spray drying methods to form stable microcapsules. The review also provides information on different types of spray drying equipment and process parameters like the type of atomiszer and nozzles, inlet–outlet temperature and type of cyclones. All the process parameters and materials are found to influence the physicochemical properties of the microencapsulates of essential oils. The review also discusses the effects of process parameters and materials on the encapsulation efficiency, moisture content, bulk and tapped density, agglomeration properties and thermal stability of the microencapsulates. Thus, the consolidated review will provide an overview of various optimization parameters and governing factors for obtaining microencapsulates of essential oils.