Flavour and Fragrance Journal最新文献

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.

In order to develop food or tobacco usable flavour precursors, compounds 2-hydroxypropyl benzoate (3a), propane-1,2-diyl dibenzoate (4a), 2-hydroxypropyl cinnamate (3b) and propane-1,2-diyl (2E,2′ E)-bis(3-hydroxypropyl cinnamate) (4b) were synthesized by transesterification propanediol with vinyl benzoate and vinyl cinnamate under the biological enzyme Novozym435. The structures of the propanediol esters were characterized using nuclear magnetic resonance (¹H NMR, ¹³C NMR), infrared spectroscopy (IR) and high-resolution mass spectrometry (HRMS). The hygroscopicity and moisture retention capacity of reconstituted tobacco shreds with the synthesized propanediol were explored by 100 h hygroscopic desorption assay, model validation and low-field nuclear magnetic resonance imaging (LF-NMR). The results showed that the bound water content of 3a and 3b was lower than that of propanediol and higher than that of the control under both low (RH = 32%) and high (RH = 84%) humidity conditions. In addition, pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) technique was applied to investigate the thermal behaviour of 3a and 3b. Four and five pyrolysis products were formed by pyrolysis of 3a and 3b, respectively. The main pyrolysis products benzoic acid and cinnamic acid could be used as flavouring agents in food and tobacco. 3a and 3b had good moisture and humidity retention effects as well as uniform and sustained flavour release. The results of the study not only effectively improve the water absorbency of reconstituted tobacco and enhance the flavour, which is suitable for the storage and smoking process, but also provide a reference for the further development of new flavour moisturizers in the tobacco industry.

Abri Herba (Jigucao) and Abri mollis Herba (Maojigucao) are derived from dried plants of Abrus cantoniensis Hance (Leguminosae) and Abrus mollis without pods. Abri Herba is commonly used in Jigucao tablets; Abri mollis Herba is usually used in Jigucao capsules and FufangJigucao capsules. Surprising, there are few reports focused on the quantitative control of these mentioned Jigucao related pharmaceuticals. This research endeavour has harnessed the formidable power of cutting-edge ACQUITY UPLC technology to formulate a groundbreaking methodology for the simultaneous quantification of 10 target compounds in Jigucao capsules, Jigucao tablets and FufangJigucao capsules. The primary aim is to bolster quality control and precise identification within the realm of these pharmaceutical products. Separation was performed on an ACQUITY UPLC HSS T3 Column (2.1 × 100 mm, 1.8 μm), gradient elution was performed with 0.1% formic acid in water and acetonitrile. A column temperature of 40°C acts as our guiding compass, and DAD detection scans the spectral landscape in the wavelength range of 210–400 nm. The concentrations of the 10 target components can be used to identify Jigucao tablets, Jigucao capsules and FufangJigucao capsules through the art of chemometrics. The results showed that the established method for determination of 10 target compounds was accurate and reliable with good linearity (r ≥ .9948) and satisfactory recoveries (82.91%–108.6%). The identification of the three Jigucao related pharmaceuticals can be performed using chemometrics based on the 10 target compounds. Thus, our study not only showcases a pioneering analytical approach but also unveils a new dimension in the identification of these pharmaceutical treasures.

The evaporation of fragrances with volatilities spanning over several orders of magnitude results in a shift of the olfactive impression of a perfume over time. Fixatives have repeatedly been used to slow fragrance evaporation in multiple perfumery applications. We developed a simple and reliable method to measure the evaporation kinetics of individual fragrances in a model perfume and analysed the fixative effect of 2-oxo-2-phenylacetates (α-ketoesters) on perfume evaporation. 2-Oxo-2-phenylacetates, some of which have been described as light-sensitive profragrances, are commercially available or readily prepared by esterification or transesterification of commercial starting materials. (−)-Menthyl 2-oxo-2-phenylacetate afforded single crystals that were suitable for X-ray crystal structure analysis. 2-Oxo-2-phenylacetates were found to have a fixative effect on the evaporation of fragrances with volatilities below 5000 μg L⁻¹ in fine fragrance and eau-de-toilette applications. The molecular structure of the compound rather than its molecular weight had an impact on the fixative effect to some extent.

There are many methods reported to identify and quantify volatile compounds. Many of them are based on chromatographic techniques, such as high-performance liquid chromatography (HPLC), gas chromatography with flame ionization detector (GC-FID), and GC coupled with mass spectrometry (GC–MS). But among all GC-FID and GC–MS are majorly used for the detection and quantification of volatile compounds. A new gas chromatographic method has been developed for simultaneous determination of six flavouring agents [menthol, benzyl alcohol, methyl salicylate, anethole, menthol carboxamide (WS-3) and eugenol] in herbal freshness gel toothpaste. All six flavours were separated using a DB-WAX (Agilent) capillary GC column (30 m × 0.25 mm × 0.25 μm) and flame ionization detector (FID). This method was validated for various parameters such as precision, linearity, accuracy, stability, robustness, limit of detection, and limit of quantification as per ICH guidelines, AOAC internationals Appendix K. All the validation parameters were found to be within acceptable limits. The method was successfully applied for the quantification of all flavouring agents in toothpaste formulations.

The utilization of essential oils spans across various industries, encompassing food, pharmaceuticals, and cosmetics. Lemongrass, an herb renowned for its high essential oil content, was the focal point of this research. The objective was to explore a novel approach to extract essential oil from lemongrass by employing ultrasonic sparger-based microwave-assisted extraction (U Sp-MAE) coupled with ultrasound sonicator pretreatment. The findings revealed that the application of the U Sp-MAE technique, combined with ultrasound sonicator pretreatment, resulted in a significant increase in lemongrass essential oil yield. At a mixing ratio of 80 g of chopped lemongrass per 500 mL of deionized water, a remarkable yield of 1.87% was achieved. This study demonstrates the potential of the U Sp-MAE technique, with ultrasound sonicator pretreatment, as a promising and efficient method for extracting essential oil from lemongrass. Furthermore, its potential applications extend to industrial settings, offering new avenues for utilization.

The aroma of cooked rice is a key factor in the evaluation of taste quality for rice grading, which greatly affects consumer acceptance. Combining the results of instrumental analysis and sensory evaluation to comprehensively analyse the aroma of cooked rice is a new strategy. The aroma characteristics of fifteen cooked rice varieties were analysed by gas chromatography–mass spectrometry (GC–MS) and descriptive sensory analysis. Based on the aroma descriptors obtained by gas chromatography-olfactometry (GC-O) analysis and the odour activity value (OAV) of aroma compounds, the aroma profiles of cooked rice were preliminarily explained by bipartite network and aroma fingerprint. The Pearson correlation coefficients between the OAV results of aroma compounds and sensory data were calculated to construct the aroma association network. The results showed that the aroma attributes of cooked rice were significantly correlated with certain aroma compounds identified by GC–MS, such as aldehydes and heterocycles. The aroma attributes of cooked grain, popcorn, grassy, nutty, and fruity could be well explained by the results of GC–MS analysis. The purpose of the study is to better understand the relationship between aroma characteristics and chemical composition, as well as to provide a theoretical basis for evaluating and predicting the aroma of cooked rice using GC–MS analysis.