Flavour and Fragrance Journal最新文献

Different types of tobacco should exhibit significant differences in pyrolysis behaviour and pyrolytic aroma components distribution due to their intrinsic microstructures and chemical composition features but rarely be compared. Herein, the pyrolysis characteristics of three types of tobacco (oriental tobacco, burley tobacco and flue-cured tobacco) were studied by using thermogravimetric technique combined with thermal analysis kinetics method. The weight loss processes of each tobacco sample can be divided into four stages, namely dehydration, decomposition of volatile components, decomposition of hemicellulose and cellulose, and decomposition of lignin and carbonisation. Different types of tobacco exhibited various pyrolysis characteristic parameters in terms of T_i, T_f, DTG_max, and CPI, indicating an obvious difference in the thermal decomposition characteristics of tobacco. And then a stepwise heating strategy was designed to in-depth investigate the pyrolysis characteristics and release behaviour of aroma components at different thermal weight loss stages by using the self-built infrared tube furnace combined with Cambridge filter capture system. The weight loss stages II and III would generate most of the aroma components for each type of tobacco. The release amount of oxygen heterocyclic and ketone compounds exhibited the order of flue-cured tobacco (558.90 μg·g⁻¹) > burley tobacco (423.44 μg·g⁻¹) > oriental tobacco (291.55 μg·g⁻¹) during the four stages. The release amount of nitrogen heterocyclic compounds exhibited the order of burley tobacco>flue-cured tobacco>oriental tobacco, while the organic acids exhibited the opposite order. Furthermore, the physicochemical properties of biochar generated from different types of tobacco were characterised and compared by elemental analysis, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). This study may provide guidelines for the rational utilisation of different types of tobacco leaves in related products.

Headspace solid-phase microextraction-gas chromatography–mass spectrometry (HS-SPME-GC–MS) and electronic nose analysis were used to analyse the changes in volatile components in the Maillard reaction products (MRPs) under various reaction temperatures and reaction times. The results indicate that with increased thermal reaction intensity, both the variety and content of aldehydes, ketones, and heterocyclic compounds in the MRPs significantly increased, with MRPs obtained at 120°C for 30 min exhibiting the highest umami and meaty aroma. The study elucidated the impact of different reaction temperatures and times on the volatile compounds and flavours of MRPs from chicken bone enzymatic hydrolysate, and identified the optimal reaction temperature and time for the Maillard reaction of chicken bones. This effectively enhances the utilisation of chicken bone protein in flavoured foods.

Volatile compounds produce the aroma of fruits such as Citrus limon and play a key role in fruit quality. Moreover, drying technology plays a significant role in aroma quality. To reflect the volatile differences and the dynamic change of volatile profiles of dried lemon peel as affected by drying methods, the volatile compounds of dried peel prepared under three drying methods were analysed by gas chromatography–mass spectrometry combined with chemometrics. According to the results, drying at 35°C allowed to obtain peels with high titratable acidity, high flavonoid content and high antioxidant activity. On the other hand, vacuum freeze drying allowed to obtain samples with high total soluble solids and highest polyphenol contents. Eight volatile compounds were identified, with beta-and alpha-pinene and limonene found to play an important role in the discrimination of the different drying processes, based on variable importance in projection ≥ 1.2. These substances might be responsible for what caused the significant flavour difference between differently dried peel flours. The combination of HS–GC–MS and chemometrics offers a valuable tool for the identification of type-specific volatile markers in lemon peels. This study provided an important study for the improvement of processing and design technology and quality enhancement of C. limon peels, in order to meet consumer demand.

Betel nut possesses a distinctive flavour that appeals to specific consumers, despite the well-documented risks of oral diseases associated with its use. Understanding the characteristic aroma of betel nut is essential for developing appealing substitutes. In this study, supercritical CO₂ fluid extraction was employed to obtain extracts from green and black betel nuts, and the volatile compounds were analysed using headspace solid-phase microextraction. A total of 30 volatile compounds were identified in green betel nuts and 37 in black betel nuts. Through the odour activity value (OAV) method, 14 key aroma compounds were identified in black betel nuts (FD ≥ 16, OAV ≥ 1). These findings were further validated by aroma reconstitution and omission tests. The aroma synergy of these compounds was also examined using the S-curve and σ-τ methods, revealing that smoky compounds significantly masked the perception and intensity of other aroma components. This study provides valuable flavour data for the development of betel nut substitutes, which could contribute to reducing the health risks associated with betel nut consumption.

The flavour quality of Lentinus edodes chicken meat filling with varying proportions of mushroom was analysed using gas chromatography–mass spectrometry (SPME-GC–MS), electronic sensory technology and fuzzy mathematical sensory evaluation. The results indicate that the addition of Lentinus edodes increased the content of unsaturated fatty acids by 3.97% and total volatile compounds by 79.20%, compared to the filling without Lentinus edodes. Furthermore, the ratio of umami amino acids increased by 6.54%. Spearman correlation analysis revealed that sensory scores are influenced by multiple factors rather than a single or few factors alone. Correlation analysis demonstrated a positive relationship between sensory score and the content of flavour amino group and Mushroom alcohol, while showing a negative correlation with the content of 5′-GMP. These findings suggest that changes in the proportion of dry and fresh Lentinus edodes significantly impact the flavour profile of chicken stuffed with Lentinus edodes.

Embedding is an effective method to overcome the poor thermal stability and release properties of lemon essential oil (LEO). This research focused on the fabrication of inclusion complexes through co-precipitation and response surface optimization, employing Fenugreek polysaccharide (FP15) as the wall material. The complexes were assessed through thermal analysis and in vitro slow-release investigations. XRD, FTIR and SEM analysis proved that LEO formed supramolecular structure with FP15 through hydrogen bonding and van der Waals force, and was successfully embedded with packaging efficiency of 57.33%. Thermal behaviour analysis showed that FP15 as a wall material significantly improved the thermal stability of LEO. The analysis based on the KAS and Coats-Redfern methods showed that the apparent activation energy of inclusion compounds increased with the increase of conversion rate, and the secondary reaction model (F2) could better describe the pyrolysis reaction mechanism of inclusion compounds. In vitro release experiments showed that the release of LEO from the inclusion at 37°C (human body temperature) and 65°C (food processing temperature) followed a first-order kinetic model, with LEO being released from the carrier by non-Fickian diffusion. The analysis of pyrolysis products showed that the inclusion compound pyrolyzed at 300°C, 600°C and 900°C to produce a large number of aldehydes, esters and non-/semi-volatile organic acids. The production of these flavour substances improves the quality, concentration of aroma, rich-ness and harmony of the cigarette during smoking. In summary, FP15 as a wall material slowed down the release of LEO, enhanced its stability and improved the sensory quality of cigarettes.

Our current study investigated the effects of exogenous ATP (adenosine triphosphate) on the post-harvest quality of grape (Vitis vinifera L.) fruits. The results demonstrated that treatment with exogenous ATP effectively alleviated the decreases in fruit firmness, total soluble solids (TSS), vitamin C content and soluble protein of the harvested grape fruits. Furthermore, exogenous ATP also significantly enhanced the content of the titratable acidity (TA) of grape fruits after harvest. This was reflected by the observations that ATP treatment increased the hardness, TSS content, vitamin C content and soluble protein content of the harvested grape fruits by 14.39%, 6.29%, 31.05% and 15.18% on average during 8 days of storage, respectively, compared to the controls. In addition, the harvested grape fruits treated with exogenous ATP had higher activities of SOD (superoxide dismutase) and CAT (catalase) and higher contents of total phenolics and flavonoids compared to the controls. This was reflected by the observations that ATP treatment increased the SOD activity, CAT activity, flavonoid content and total phenol content by 39.79%, 19.43%, 17.74% and 15.06% on average during 8 days of storage, respectively, compared to the controls. These observations highlighted that exogenous ATP can function in alleviating the decrease in quality of grape fruits after harvest and increasing the antioxidative ability of harvested grape fruits during the storage period. Consequently, treatment with exogenous ATP could offer an efficacious approach for preserving the quality of grape fruits during the storage period.

Vanillin (4-hydroxy-3-methoxybenzaldehyde) is a phenolic aldehyde compound found in the plants of the genus Vanilla. This substance is widely used as a flavouring in the world, used in the food even pharmaceutical industries. Some studies have reported pharmacological activities such as antitumor, antinociceptive, anti-inflammatory and neuroprotective activities. This study aimed to investigate the spasmolytic, antitussive, expectorant and anti-asthmatic effects of vanillin in rodents. The spasmolytic activity of vanillin was assayed in isolated rat tracheas that were contracted with carbachol or KCl. The in vivo effects were evaluated in mouse models of citric acid-induced cough, phenol red dosage in bronchoalveolar lavage and ovalbumin-induced asthma. The maximal relaxing effect promoted by vanillin in isolated rat trachea was greater in contractions induced by KCl 60 mM than by carbachol (10 μM). In calcium-free media, this effect was significantly reduced during CCh-induced contractions. Vanillin at doses of 10, 30 or 100 mg/kg reduced the number of inflammatory cells in bronchoalveolar lavage and the number of coughs in mice after treatment. The effect of vanillin may be related to the opioid receptor, as the antitussive effect was abolished in the presence of 0, 4 mg/kg naloxone. The vanillin-loaded nanoemulsions exhibited expectorant activity. The present study showed that vanillin may be responsible for these anti-asthmatic, antitussive and spasmolytic effects.

The active sites of waste copper slag were moulded using BaO and used as a catalyst for the esterification reaction without solvent. Various concentrations of BaO were doped over the copper slag and investigated for the esterification of various model components of flavour, fragrance and biofuel. The catalyst was characterised by X-ray photoelectron spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, surface area analysis and X-ray diffraction to examine the impact of BaO addition on the structural and morphological characteristics of BaO_X/Cp-Sl. BaO increases the grain size and enhances the BaO_X/Cp-Sl catalyst's activity and selectivity to flavour, fragrance and biofuel. The BaO_2.5%/Cp-Sl catalyst showed the maximum conversion of oleic acid to the methyl ester. The esterification of various commercially important substrates like geraniol, citronellol, menthol, isoamyl acetate, palmitic acid and waste cooking oil using a catalyst has been explained in detail. The kinetic study of the esterification has been explained with turnover number (TON) and turnover frequency (TOF). The mechanism pathway of the catalyst with various active sites of waste copper slag has been explained using adsorption studies.

Thymol (THY) is a natural antioxidant and antimicrobial; however, its biological activity and application in the food and pharmaceutical fields are limited due to its low water solubility and volatility. In this study, inclusion complexes of cationic-β-cyclodextrin-THY (C-β-CD-THY) were prepared by using the aqueous stirring method. Then UV–Vis spectra, FT-IR, NMR, DSC, XRD and SEM data were collected to characterise the structure and morphology of the inclusion complexes. Phase solubility experiments showed a better solubilisation effect of C-β-CD-THY than HP-β-CD-THY. At a concentration of 0.64 mmol/L for THY, the DPPH scavenging rate was 60.99% and 61.31% for HP-β-CD-THY and C-β-CD-THY, respectively, whereas that of THY in 10% ethanol was only 43.47%. The bacteriostatic activity was verified using a circle of inhibition and the live/dead bacterial double stain. C-β-CD-THY exhibited better antimicrobial activities against Escherichia coli and Staphylococcus aureus than HP-β-CD-THY. In conclusion, the C-β-CD-THY inclusion complexes have the potential to be applied as an effective bacteriostatic agent for food and pharmaceutical applications.