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This study aimed to investigate the impact of spicy stimuli on the respiratory status of rats inhaling aerosols of spicy substances. The intensity of spicy stimuli was characterized by examining changes in multiple respiratory function indicators. Changes in various respiratory function indicators of rats inhaling different concentrations of two representative spicy substances, capsaicin and nicotine, were monitored in real time using an unrestrained whole-body plethysmograph system fitted with a nebulized drug delivery device. The results demonstrated that sensory stimulation of capsaicin and nicotine elicited similar respiratory patterns, which were manifested by an enhancement of respiratory rhythm at low concentrations and a suppression of respiration at high concentrations. Low-intensity spicy stimulation elevated respiratory rate, reduced relaxation time, and increased mid-expiratory flow rate, while high-intensity spicy stimulation had reverse effects. Additionally, heightened spicy stimulus intensity resulted in a sustained increase in the airway narrowing index. Concentration effect curves corroborated an evident correlation between spicy stimulation intensity and respiratory function indicators. The sensory stimulation intensity of various spicy substances could be objectively characterized by monitoring changes in the airway narrowing index. This study has established a novel method for objectively assessing the sensory stimulation intensity of spicy substances, providing a novel mean and reference for further exploring the brain region effects underlying the perception of spicy flavor in experimental animals.

Sweeteners cannot completely replace the satisfaction provided by sugars, even though they offer a similar flavor perception and much higher sweetness intensity than sugars. Clarifying the biological mechanism of this phenomenon is important to improve the functional evaluation system for sweeteners and promote sweetener innovations. Herein, we review the research progress on the difference in the behavioral preferences of animals, the activity of brain regions and the activation patterns of the gut-brain axis induced by sugars and sweeteners, and we uncover the underlying reason why the brain distinguishes sugars from sweeteners, causing differences in individual behavioral preferences. Moreover, we propose that animal behavior, neural activity in brain regions, and the capacity to activate key receptors can be used to evaluate the gut-brain axis effects of sweeteners, which will provide a reference for innovative developments in the field of sweeteners.

We pioneered an angle-adjustable photonic crystal fluorescence platform (APC-Fluor) that integrates PCs, an angular resolution spectrometer and a strategically aligned laser source. This configuration, featuring a coaxial rotating swing arm, allows for precise control over the angles of incidence and emission. The presence of photonic crystal microcavities facilitates the dispersion of fluorescent materials and promotes the transition of electrons from the excited state to the lowest vibrational energy level. The optical resonance effect triggered by modulating the alignment of the reflection peaks of the photonic crystals with the emission peaks of the fluorescent materials can significantly enhance the fluorescence intensity. Compared with the single BSA-AuNCs, the optimized fluorescence intensity can be significantly increased by 11.9-fold. The APC-Fluor system showcases rapid and highly sensitive detection capabilities for oxytetracycline (OTC), exhibiting a response across a concentration range from 2 to 1 × 104 nM and achieving a notably low detection limit of 1.03 nM. [ABSTRACT FROM AUTHOR]

To investigate the differences in aroma structure of different types of cigarettes, the contents of 8 groups of aroma components in the total particulate matter (TPM) of 15 types of cigarettes were analyzed by GC-MS. The aroma activity values of each aroma component and the SOAV of each component group were calculated. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to analyze the different aroma groups of the cigarettes and to classify the cigarette samples. The results showed that: 1) The amount of aroma components released in the same group showed a strong common pattern. 2) The contribution weight of burnt-sweet aroma component group was the highest in the 8 groups of Chinese-style cigarettes. The contribution weight of the burnt-sweet aroma component groups decreased in the US blended cigarettes, and that of the British flue-cured type of cigarettes was between the Chinese-style cigarettes and the US blended cigarettes. 3) Chinese-style cigarettes could be effectively distinguished from the foreign cigarettes by PCA. HCA divided the cigarette samples into two categories, Chinese style cigarettes and foreign brands. Furthermore, HCA could separate No. 1 cigarette sample with special aroma structure and No. 11 and No. 12 cigarette samples from the other Chinese style cigarette samples. [ABSTRACT FROM AUTHOR]

In order to investigate the influence of aroma characteristic components in tobacco extracts on the style characteristics of cigarettes, three types of tobacco extracts from Fujian, Guizhou and Hunan were prepared by sub- critical extraction-molecular distillation technique, and the mass concentrations and aroma activity values (OAV) of aroma characteristics of burnt sweet, creamy, soy, spicy, fruity, sour, nutty and floral aromas were investigated systematically. The effects of OAV changes on the style characteristics of tobacco extracts were investigated by sniffing and cigarette smoking evaluation. The results showed that the total mass concentrations of aroma components of the three tobacco extracts were 2 427. 62 μg / mL, 3 688. 96 μg/mL, and 4 628. 06 μg/mL, respectively. Burnt sweet, creamy, sour and floral aromas varied among the three tobacco extracts. Fujian tobacco extracts were dominated by floral, burnt sweet and creamy aromas, while Guizhou tobacco extracts and Hunan tobacco extracts were dominated by sour and floral aromas, but with different weights. Based on the differences of the three extracts' aromatic characteristics OAV, the representative components of each flavor characteristic were added on the basis of Fujian tobacco extract. The light aroma style characteristics of the imitation tobacco extracts were weakened and the strong aroma style characteristics gradually appeared. [ABSTRACT FROM AUTHOR]

This study describes the enhancement in the solubility and controlled‐release of fragrance agents (menthol, four n‐alkanols, and three aromatic esters) using three CO2 switchable surfactants (N‐alkylimidazolium bicarbonates). The surfactants significantly improved the solubility of fragrance agents in water. N‐Dodecylimidazolium bicarbonate was the most effective surfactant to solubilize menthol. A stability test indicated that the surfactant could stably disperse menthol in water. Moreover, the surfactants improved the solubility of n‐alkanols to different levels, however, the solubility of the aromatic esters equally. The release of menthol from the surfactant solution under N2 at different durations of bubbling time, temperatures, and flow velocities were studied. [ABSTRACT FROM AUTHOR]

In order to investigate the effects of different matrix on the sensory characteristics of nicotine, the sensory characteristics of nicotine at different contents in aqueous solutions, hydrophilic aerosol (propylene glycol) and lipophilic aerosol (glyceryl triacetate) media were systematically evaluated, and the nicotine's flavor detection threshold in each of the medium was also determined. The fractions of free-base nicotine (αfbn) in aqueous solutions and aerosol condensates with different contents of nicotine were calculated on the basis of pH values or NMR spectra respectively. The effects of lactic acid and menthol on the sensory characteristics, flavor detection thresholds and αfbn of nicotine in those media were investigated. Furthermore, the sensory effects of nicotine in different aerosols at the same concentration were compared, and the influence of solvent polarity on the gas phase partitioning of nicotine were studied by solid phase micro-extraction gas chromatography-mass spectrometry (SPME-GC/MS). The results showed that: 1) With the adopted sensory evaluation approach, nicotine aqueous solutions mainly caused oral irritation, and their nicotine aerosols created impact on the throat and caused irritation to the nasal cavity and the throat. 2) The flavor detection thresholds of nicotine in aqueous solutions, propylene glycol aerosol and glyceryl triacetate aerosol were 0.072, 0.296 and 0.197 mg/g respectively. 3) In different media, lactic acid reduced the nicotine irritation and increased its detection thresholds by reducing αfbn significantly. Menthol, however, had similar sensory effects without changing αfbn. Aerosol media with different polarities influenced the sensory characteristics and flavor detection threshold of nicotine by affecting its gas phase distribution. [ABSTRACT FROM AUTHOR]

To investigate the key burnt-sweet, creamy and bean aroma components in mainstream cigarette smoke and their distribution characteristics as well as sensory contributions, and to guide the flavoring of tobacco products effectively, the tobacco and tobacco smoke components listed in The Chemical Components of Tobacco and Tobacco Smoke were systematically evaluated. The components with burnt-sweet, creamy and bean aroma characteristics were screened and identified, and their distribution characteristics in total particulate matter (TPM) of mainstream smoke from 9 cigarette brands were determined by GC/MS. The contributions of those components to the burnt-sweet, creamy and bean aroma notes in mainstream cigarette smoke were assessed based on their odor activity values (OAVs). The results showed that: 1) There were 18 components with burnt-sweet aroma note, 15 with creamy aroma note and 5 with bean aroma note in mainstream cigarette smoke. 2) In the mainstream smoke of different types of cigarettes, the releases of hydroxyacetone, 2, 3-butanedione, methyl cyclopentenolone and 4-hydroxy-2,5-dimethyl-3(2H)-furanone were higher than those of the other components. 3) The total releases of the above 38 components in mainstream smoke of blended type cigarettes were remarkably lower than those of Virginia type cigarettes. 4) The contribution of burnt-sweet aroma note to mainstream cigarette smoke was more significant than that of creamy and bean aroma notes. The key components with burnt-sweet aroma note were 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 3,4-dimethyl-1, 2-cyclopentadione, methyl cyclopentenolone and 3-ethyl-2-hydroxy-2-cyclopenten-1-one, those with creamy aroma note were 2,3-butanedione, ethyl vanillin and vanillin, and those with bean aroma note were 6-methylcoumarin and dihydrocoumarin. [ABSTRACT FROM AUTHOR]

The transfer rates to particulate phase of mainstream cigarette smoke and olfactory thresholds of 15 endogenous acidic aroma components in cigarette smoke were studied. The ratio of transfer rate to olfactory threshold of each component was defined as its "flavoring contribution" to characterize the difference in contributions of aroma components to sensory characteristic of cigarette smoke. The results showed that: 1) The transfer rate of acetic acid was the highest (36.61%), and those of the other 14 acidic aroma components ranged from 9.67% to 17.15%. 2) The flavoring contribution of isovaleric acid was the highest (169.76), and those of 3-methylvaleric acid, valeric acid, and butyric acid were in the range of 14.25-52.13, and those of acetic acid, 2-methylbutyric acid, 2-methylvaleric acid, hexanoic acid, 3-phenylpropionic acid were from 1.59 to 4.55, and those of the other components were less than 1.00. 3) The flavoring contribution integrated transfer ratio and olfactory threshold of aroma components and could comprehensively and authentically reflect the differences of flavoring components in influencing the sensory characteristics of cigarette smoke, which could be used to guide cigarette flavoring. [ABSTRACT FROM AUTHOR]

Abstract: A visible‐light‐driven sequential photoredox catalysis to allow N‐aryl α‐amino acids to experience efficient cascade aerobic decarboxylative Povarov and oxidative dehydrogenation (ODH) reactions is described. With a dicyanopyrazine‐derived chromophore (DPZ) as a photoredox catalyst in both transformations, two series of valuable azaarenes, i. e., 4‐amino tetrahydroquinolines (THQs) and quinolines, were obtained in satisfactory yields featuring diverse 2‐ and 2,3‐substituent patterns. To enable the ODH reaction of 4‐amino THQs, a cooperative catalysis with N‐hydroxyphthalimide was developed. Additionally, an unprecedented synthesis of chiral N‐amino‐2‐methyl THQs with high enantioselectivities was realized. [ABSTRACT FROM AUTHOR]