The brewing process is a crucial step in determining the flavor profile of green tea infusions. However, the flavor differences arising from top-brewing and bottom-brewing methods remain poorly understood, and the underlying mechanisms are largely unexplored. In this study, GC-MS and sensory analysis were employed to investigate the flavor differences in Shucheng Little Cymbidium tea infusions under varying water temperatures and brewing methods. Subsequently, the variations in major polyphenolic compounds were analyzed, and the potential causes of flavor differences were explained from the perspective of the interactions between EGCG and key aroma compounds. Multivariate statistical analysis revealed that compounds such as geraniol, nonanal, and methyl salicylate serve as important markers for discriminating between different brewing conditions. Moreover, EGCG exhibited a significant binding effect with compounds such as geraniol and nonanal, driven by hydrogen bonding and hydrophobic interactions. This binding may regulate the transfer of aroma compounds from tea leaves to the infusion during brewing, thereby shaping distinct sensory characteristics. These findings provide a molecular-level rationale for empirical techniques in traditional tea art. More importantly, it inspires researchers to pay attention to the crucial role of the tea infusion matrix in determining flavor.

Tobacco-specific nitrosamines (TSNAs), potent carcinogens formed during tobacco fermentation, accumulate more readily at high temperatures, particularly during cigar production. This study isolated thermotolerant bacterial strains able to degrade nitrite (as major TSNAs precursor) and suppress TSNAs formation at elevated temperatures. A novel strain, Mixta calida LYS12 belonging to the Erwiniaceae family, isolated from cigar tobacco leaves, exhibited > 95

Background Natural pungent spices represent a readily accessible dietary source of bioactive phytochemicals with well-documented nutritional and pharmacological properties. Disruption of this equilibrium, which is characterized by microbial dysbiosis, epithelial barrier compromise, and immune dysregulation, is a central feature in the pathogenesis of inflammatory bowel disease (IBD). Despite growing interest in dietary interventions, the mechanistic basis by which pungent spice-derived compounds collectively regulate gut homeostasis remains poorly synthesized, and no comprehensive review has systematically integrated their multi-target anti-inflammatory, antioxidant, and microbiome-modulatory effects in the context of IBD. Scope of review To address this gap, we systematically reviewed the therapeutic potential of eight commonly consumed pungent spices — chili peppers, pepper, mustard, ginger, cinnamon, cloves, fennel, and patchouli — and their bioactive derivatives. We synthesized current experimental and preclinical evidence with particular focus on their ability to suppress pro-inflammatory signaling (notably the TLR/NF-κB and NLRP3 axes), activate Nrf2-dependent antioxidant defenses, and remodel gut microbial ecology. Major conclusion The available evidence demonstrates that pungent spices exert coordinated multi-target protective effects on intestinal homeostasis, acting synergistically across inflammatory, oxidative, and microbial pathways. This mechanistic synthesis provides a conceptual framework for the rational development of spice-derived functional foods and highlights their potential application as complementary interventions in IBD management.

In this study we developed a novel carrier material that can be used to regulate nicotine release profile to provide a more constant release. Bacterial cellulose (BC) was produced by fermentation of tobacco waste, nicotine was derived from the backfilling of tobacco extracts. Citric acid (CA) has been used to react with bacterial cellulose to prepare an aerogel (CA-BC) which showed to possess sustained nicotine release by varying CA and its crosslinking ratio with BC. Aerogels prepared at 10% CA/BC ratios during crosslinking exhibited significant sustained nicotine release effects. Another notable finding was that the sustained-release of nicotine for the CA-BC aerogel with high nicotine contents significantly outperformed that of low nicotine contents. The Weibull model and Gallagher-Corrigan model were used to elucidate the mechanism of nicotine dissolution from CA-BC aerogels. Material characterization revealed that the CA-BC aerogel had an improved thermal stability and decreased water absorption, a 3D fiber network structure at the microscopic level with an optimal average pore size of 30 μm was used to explain this difference.

Development of combined mass spectrometry ionization sources has enabled expansion of the application and scope of mass spectrometry. A novel hybrid ionization system combining vacuum ultraviolet (VUV) and atmospheric pressure chemical ionization (APCI) was constructed. Gaseous samples were self-aspirated into an ionization zone through a capillary by negative pressure, generated by high-speed airflow based on the Venturi effect. Compared with APCI mode alone, the signal-to-noise ratio (S/N) in APCI/VUV mode was increased by about 276-times. To increase the ionization efficiency further, correlated experimental conditions were optimized. Four types of volatile organic compounds (VOCs) were tested to evaluate the performance of the APCI/VUV ion source. Excellent linearity and limit of detection were achieved for compounds in mixed solutions. Quantitative analyses of four VOCs (toluene, cyclohexanone, styrene and ethylbenzene) using APCI/VUV-MS were done, and the relative standard deviations (RSDs) were 1.57%, 6.30%, 4.49% and 8.21%, respectively, indicating that the APCI/VUV ionization source had excellent reproducibility. Our results demonstrated that the developed method was promising for analyzing VOCs as well as being rapid, simple, and easy to operate. An atmospheric pressure chemical ionization/photoionization combined ionization source was built through the Venturi effect for introducing samples to detect volatile organic compounds.

Olfaction appeared much early than other senses for avoiding danger, seeking food and communication. Olfactory analysis is the key point in some industrial production processes and unique technological fields. Human olfaction plays an important role in real-time detection, olfactory assessment, threshold determination etc. Although, the demands for multiple objective analytical methods and precise quantitative analysis could boost the development of sensor-based instrumental olfaction, the research of human olfactory detection is the source and foundation of the artificial olfaction and electronic nose. This review summarizes the analytical applications of human olfaction and also presents the promising techniques for olfactory analysis. In addition, the combination of olfaction and analytical instruments is systemically discussed. Finally, the bionic sensors based on human olfaction are also reviewed in this work. With better understanding of analytical techniques of human olfaction, new methods of olfactory analysis could be discovered, enlightening the methodology of sensory analysis and the development of artificial olfaction.

Competitive release is an important release pattern of β-cyclodextrin (β-CD) inclusion complexes. Releasing flavor by absorbing harmful molecules is an ideal situation. Thus, two inclusion complexes, phenethyl alcohol β-CD inclusion (PACD) and phenol β-CD inclusion (PNCD), were prepared and their combining capacity was studied. The binding constant of PNCD was over 9 times more than PACD. PN could accelerate the release of PACD by entering the empty β-CD, revealing competitive release effect. However, we noticed that weak-combining molecules also induced competitive release effect. PACD and PNCD were treated with several different competitors, demonstrating that the release behavior of β-CD inclusion complexes could be controlled by changing competitors. However, the process lasted much longer for “weak” molecules to exchange “strong” ones. The mechanism of competitive release of β-CD inclusion complexes was conforming to chemical equilibrium theory. The release rate could be adjusted by changing the competitors with different concentration and different combining capacity. Moreover, solid inclusion complexes could interact with gaseous competitors, revealing competitive release effect. Competitive release effect could achieve the release of flavor while absorbing harmful molecules. Also, combining capacity or solvent condition was not the determination of competitive release effect, but also an adjustment strategy for molecule release, largely expanding the application of β-CD inclusion complexes.

Electronic cigarettes (E-cigarettes) have become popular around the world. An important reason is the variety of available flavors. However, many countries have imposed restrictions on flavor substances in E-cigarettes due to their potential health risks. Therefore, it is necessary to develop an effective way to identify flavorings in E-cigarette liquids. In this work, direct analysis in real time-mass spectrometry (DART-MS) in the quick strip (QS) mode was developed and applied to determine flavorings in the E-cigarettes. Vanillin, ethyl vanillin, maltol, and ethyl maltol were quantified. Meanwhile, the ionization efficiency of flavorings in the different solvents was compared in the QS mode, which revealed that the solvent boiling point was related to the analyte ionization efficiency. The effect of endogenous matrix (propylene glycol and glycerol) on flavoring ionization was also investigated. Calibration curves with satisfactory linearity (R-2 > 0.99) were established from 1 to 1000 mu g L-1. Good sensitivity (limits of detection [LODs] < 0.3 mu g L-1), recoveries (92.6% to 104.7%), and acceptable repeatability (relative standard deviations < 14.6%, n = 5) were obtained. The limits of quantification (LOQs; 10-50 mu g g(-1)) for the E-cigarette liquid sample were much lower than the regulatory limits. The developed method provided a simple way for rapidly determining flavorings in E-cigarettes.

Surface browning plays a major role in the quality loss of fresh-cut potatoes. Untargeted metabolomics were used to understand the metabolic changes of fresh-cut potato during the browning process. Their metabolites were profiled by ultra-high performance liquid chromatography coupled with high resolution mass spectrometry (UHPLC-HRMS). Data processing and metabolite annotation were completed by Compound Discoverer 3.3 software. Statistical analysis was applied to screen the key metabolites correlating with browning process. Fifteen key metabolites responsible for the browning process were putatively identified. Moreover, after analysis of the metabolic causes of glutamic acid, linolenic acid, glutathione, adenine, 12-OPDA and AMP, we found that the browning process of fresh-cut potatoes was related to the structural dissociation of the membrane, oxidation and reduction reaction and energy shortage. This work provides a reference for further investigation into the mechanism of browning in fresh-cut products.

Xiao Mo Xiang You (XMXY) is a traditional Chinese sesame oil variety that is obtained through a hot water flotation process. This unique process gives the oil a unique aroma, health benefits, and excellent product stability. Although XMXY is always the most expensive among all the sesame oil varieties, it is usually used as a flavoring in many traditional Chinese daily food products and is increasingly popular. In order to reveal the characteristics of the oil, the volatile components, sensory evaluation, and oxidation stability of five XMXY samples were, respectively, analyzed by using headspace solid-phase microextraction/gas chromatography–mass spectrometry, an electronic nose, sensory evaluation, and RapidOxy. Comparisons and multidimensional statistical analysis were also carried out to distinguish XMXY from roasted sesame oil (RSO) and cold-pressed sesame oil (CSO) samples. In total, 69 volatiles were identified from XMXY, RSO, and CSO samples. Some compounds possessed high odor activity value (OAV > 1) in XMXY, including heterocyclic compounds, phenols, and sulfur-containing compounds. Additionally, they were also the main volatile components that distinguish XMXY from RSO and CSO. Roasted and nutty aromas were the dominant aroma attributes of XMXY. XMXY had better flavor intensity and oxidation stability than the other two sesame oil samples. These results are very valuable for the quality control and product identification of traditional Chinese sesame oil.

It is well known that organic acids (OAs) could affect the flavour of fruit juices and beverages. However, the molecular mechanism of aroma release is still unclear. In this study, the effects of citric acid (CA), L-(-)-malic acid (MA) and L-lactic acid (LA) on the release of six selected esters and their sensory perception were investigated by means of HS-GC-MS analyses and odour detection threshold determination, respectively. Meanwhile, the density functional theory (DFT) calculation was employed to explore the interaction modes between esters and OAs. HS-GC-MS analyses showed that the concentration and the type of OAs regulated the release of esters. The results were basically consistent with the detection threshold change of those esters. The DFT calculation suggested that the main intermolecular interaction was hydrogen bonds, and several esters could form a ternary ring structure with OAs through hydrogen bonds. The interactions can induce the different release behaviours of esters in OAs water solution. The number of carboxyl functional groups in OAs and the spatial conformation of esters appeared to influence the magnitude of the interaction. The above results demonstrated the mechanism of OAs affecting the release of esters and indicated a possible flavour control way by using different OAs and OA concentrations.

The expression level of miRNAs is closely related to the occurrence and development of various human diseases. However, they are difficult to be quantified due to the inherent nature of low expression in cells and plasmid. Simultaneous detection of multi-miRNA is more challenging. In this paper, we developed an ultrasensitive and specific multiple miRNAs detection strategy based on strand displacement amplification (SDA) reaction and analogical catalytic hairpin assembly (ACHA) reaction. The target miRNA specifically binds with the template and initiates the SDA reaction to produce abundant amplification products (triggers), which take part in the ACHA reaction on the electrode surface resulting in a decreased electrochemical response. With the help of dual amplification strategies, the linear relationship between the electrochemical signal and miRNA-122 and miRNA-21 concentration was in the range of 0.1 fM to 10 fM, with the detection limit of 0.012 fM and 0.075 fM, respectively. The electrochemical sensor can also be applied to detect other miRNA just by changing the template strands. In addition, the electrode can be regenerated by incubating with specific DNA strands.

In situ analysis of odor is an important approach to connect odor with chemical composition. However, it is difficult to conduct a rapid direct analysis of the odor sample because of low analyte concentration and sampling. To achieve the direct analysis, a carbon fiber ionization mass spectrometry (CFI-MS) method has been developed and applied to measure volatile components releasing from intact jujube. To build the CFI source, a 2.0-cm long carbon fiber bundle was integrated on the pin of a commercial corona discharge needle by mean of a 1.3-cm long stainless hollow tube. Odor sample driven by N2 gas can be directly introduced to the carbon fiber bundle to complete the ionization of analytes. Acetic acid, ethyl acetate, ethyl caproate, octyl acetate, and damascone present in jujube were selected to evaluate the performance of the CFI-MS method on quantitative analysis of the gaseous sample. Good lineary was obtained (R2 ≥ 0.9946) between 5.0 and 500.0 ng/L with limits of detection (LOD) ranging from 0.5 to 1.5 ng/L. Recoveries of five volatile compounds for the spiked jujube samples were between 94.36 and 106.74% with relative standard deviations (RSDs) less than 7.27% (n = 5). Jujube of different varieties can be distinguished by principal components analysis based on the analytical results of volatile compounds. The developed method demonstrated obvious advantages such as simplicity, high throughput, good sensitivity and wide range of applicability, which will be an alternative way for in situ analysis of the odor sample.

Introduction: To strengthen the safety control of smokeless tobacco (snus) products, an accurate method to test the nicotine release behavior from snus is very necessary. Methods: A laboratory-made flow-through device was designed to simulate snus using condition in the mouth, which was integrated with a commercial drug dissolution analyzer. Nicotine was gradually released from snus and dropped into the release solution. The release solution was analyzed by ultraviolet spectroscopy, and the spectral signal input to the system was detected by fiber optic probe and automatically processed by computer. The nicotine release behavior diagram was thus obtained. Also, the nicotine dissolution rate coefficient (a) could be calculated. Results: The results show that there was a great linear relationship between the absorbance and concentration of a nicotine standard solution at 260 nm in the range of 10-80 mu g/mL. The relative standard deviation (RSD) of nicotine release at several time periods was between 10.35% and 12.74%, indicating good repeatability. Approximately 17-85% of nicotine was released from 16 commercial snus products. The a values were between 0.008 and 0.071. Conclusions: This nicotine dissolution analyzer was designed by integrating fiber optic sensing technology, chemical spectroscopic analytical technology, and computer data processing technology. The sampling time and measurement time intervals of this method had a precision of several seconds. Thus, the design objective of the fiber optic sensing nicotine dissolution analyzer was achieved; that is, in vitro, continuous, real-time, online analysis of nicotine dissolution behavior of snus.

Background: Jujube extract is commonly used as a food additive and flavoring. The unique jujube aroma and the mild sweet aroma of the extract are critical factors that determine product quality and affect consumer acceptability. The aroma changes with changes in the extraction condition, which is typically dependent on the characteristics of volatile oils in the extract. Despite their importance, the volatile oils of jujube extract have received less attention compared with the soluble components. So, an appropriate qualitative and quantitative method for determination of the volatile oils is vitally important for quality control of the product. Results: A method coupling steam distillation/drop-by-drop extraction with gas chromatography-mass spectrometry (S3DE/GC-MS) was developed to determine the volatile components of jujube extract. Steam distillation was coupled with solvent extraction; the resulting condensate containing volatile components from jujube extract was drop-by-drop extracted using 2 mL of methyl tertiary butyl ether. The solvent served two purposes. First, the solvent extracted the volatile components from the condensate. Second, the volatile components were pre-concentrated by drop-by-drop accumulation in the solvent. As a result, the extraction, separation, and concentration of analytes in the sample were simultaneously completed in one step. The main parameters affecting the S3DE procedure, such as the water steam bubbling rate, extraction solvent volume, sample weight and S3DE time, were optimized. The standard addition approach was essential to obtain accurate measurements by minimizing matrix effects. Good linearity (R-2 >= 0.9887) and good repeatability (RSDs <= 10.35%, n = 5) for 16 analytes in spiked standard analyte samples were achieved. Conclusions: With the S3DE/GC-MS method, seventy-six volatile compounds from jujube extract were identified and the content of 16 compounds was measured. The results were similar to those from simultaneous distillation extraction. The developed method was simple, fast, effective, sensitive, and provided an overall profile of the volatile components in jujube extract. Thus, this method can be used to determine the volatile components of extracts.

A series of silicon-containing derivatives of linear alicyclic musks comprising sila-Rosamusk (3b), sila-Romandolide (5b), sila-Applelide (11b), and the corresponding dehydro derivatives was synthesized from sila-analogs of Artemone and Herbac, respectively, by means of sodium borohydride reduction and subsequent esterification with the corresponding acid chlorides in the presence of triethylamine. The olfactory properties of the new sila-odorants 3b–13b are reported in comparison with their carba-analogs 3a–13a, and quantitative threshold data allowed the generation of an improved musk olfactophore model featuring a correlation of 80.5 % with a null-cost distance of 244. This olfactophore model shows that it is likely that linear and macrocyclic musks address the same odorant receptors, and it should facilitate the design of new musks.

Si-Artemone (4a), Si-beta-Dynascone (5a), and Si-Herbac 6a, which are Si analogues of the commercial fragrance ingredients Artemone (1), beta-Dynascone (2), and Herbac (3), were synthesized expediently by the insertion of terminal alkynes into silacyclobutane 7a. The sensory characterization results revealed that 4a and 6a had quite similar odor qualities compared with those of 1 and 3, whereas 5a had a totally different odor character relative to that of 2. In terms of the odor threshold values, that of 4a was slightly more substantive than that of its carbon analogue 1, 6a was less potent than its carbon analogue 3, whereas that of 5a was approximately one-sixth that of its carbon analogue 2.

Jujube extract has a unique flavor that has been used as a common fragrance due to the volatile compounds. In this study, the volatiles of jujube extract were isolated by liquid-liquid extraction, simultaneous distillation extraction, ultrasound-assisted solvent extraction, and headspace solid-phase microextraction, and analyzed by gas chromatography-mass spectrometry. Altogether 92 compounds were identified by the four methods, of which 53 components were identified for the first time; however, only 21 compounds were identified by all these methods. The performance characteristics of the four pretreatment techniques were compared by principal component analysis which showed that the volatile compounds obtained by liquid-liquid extraction and ultrasound-assisted solvent extraction were similar both in categories and in content; whereas, the volatiles extracted by simultaneous distillation extraction, ultrasound-assisted solvent extraction, and headspace solid-phase microextraction greatly varied. The results indicated that a multi-pretreatment technique should be adopted in order to obtain the most complete information about the volatile compounds in jujube extract. The ultrasound-assisted solvent extraction method exhibited excellent repeatability and recoveries, and was very suitable for quantitative analysis. Although the recoveries and reproducibility of headspace solid-phase microextraction were inferior to the other methods, it was more sensitive than other methods.