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.

A vacuum ultraviolet-assisted electrospray ionization (VUV-ESI) hybrid ionization source was developed by orthogonally coupling 124 nm photons to the electrospray plume to enhance the ionization of moderately polar and nonpolar analytes. Using five representative volatile aroma compounds as model analytes, the VUV-ESI system produced signal enhancements of up to 46-fold relative to conventional electrospray ionization. Mechanistic analyses indicate that this enhanced ionization efficiency arises from a synergistic combination of VUV-induced solvent processes and analyte-dependent photoactivation. Specifically, VUV irradiation promotes the formation of protonated solvent clusters that sustain efficient proton-transfer reactions. Concurrently, near-resonant excitation transiently increases the proton affinity of target analytes to favor proton capture, while molecules with relatively low ionization potentials undergo direct single-photon ionization followed by rapid solvent-mediated hydrogen abstraction. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations support this analyte-dependent modulation, revealing excitation-induced increases in apparent proton affinity, exemplified by a 19.04 kcal/mol enhancement for azulene. Under optimized conditions, VUV-ESI demonstrated robust quantitative performance with coefficients of determination (R2) ≥ 0.99 and limits of detection down to 12.5 nmol/L. The method also exhibited reliable spike recoveries in complex Baijiu and essential oil matrices. These results establish the VUV-ESI hybrid source as a highly effective analytical platform for overcoming inherent ionization biases and expanding the accessible analyte coverage in mass spectrometry.

To enhance the sensory quality of yeast proteins and facilitate their broader application in food products, its key aroma compounds were systematically characterized through sensory evaluation and GC × GC-TOF-MS. The combined use of three extraction techniques (SAFE, SDE, and SPE) enabled the identification of 104 odor-active compounds. Sensory profiling revealed the roasted, sour, sweet, and almond-like were dominant. Among the three extraction methods, SAFE and SDE were optimal for bulk recovery, while SPE targeted organic acids. The aroma recombination experiments confirmed the recombination model based on the three methods demonstrates a relatively high similarity (90%) with the protein sample. The omission experiments further confirmed that benzaldehyde, n-decanoic acid, hexanoic acid, methyl benzoate, geranylacetone, 1-nonanol, 2-decanol, 2-pentadecanone, farnesol, γ-undecalactone, and octanal were identified as key aroma compounds in yeast proteins. The work establishes a robust analytical framework for yeast protein flavor characterization, aiding product development and quality control.

Background: With the increasing global demand for protein, traditional animal protein cannot meet the current protein demand due to its limited availability and high cost. As the world's third largest protein feed material after soybean meal and rapeseed meal, cottonseed meal contains a large amount of cottonseed protein. As a plant protein, cottonseed protein not only has a high yield, but also has high nutritional value. It is an economical and environmentally friendly protein that can be used as an emerging alternative protein in the food industry. Scope and approach: Although there are increasing reports on cottonseed protein as a substitute protein, there is still a lack of comprehensive discussion on its composition, activity, and applications. This article systematically reviews the composition, extraction, and function characteristics of cottonseed protein. The extensive applications in food sector and utilization limitations were introduced, providing a reference for the development of cottonseed protein in the future. Key findings and conclusions: Cottonseed protein, as a resource utilization of by-products from cottonseed meal, has a crude protein content of >= 50%. Except for slightly lower levels of methionine, the content of other essential amino acids meets the standards recommended by the Food and Agriculture Organization of the United Nations (FAO). Cottonseed protein not only shows various biological activities, but also has a wide range of applications in the food industry. This review aims to provide comprehensive understanding and practical guidance for the cottonseed protein in food applications.

Yeast fermentation has been shown to reduce the concentration of aldehydes, characteristic off-flavors in animal livers, although the underlying mechanisms of deodorization remain unclear. This study investigated the oxidative catalytic degradation of E,E-2,4-heptadienal by ALDH (Aldehyde dehydrogenase) from Saccharomyces cerevisiae within a complex system of pig liver proteins (PLvPs) and the aldehyde compound. Fluorescence quenching, thermodynamic, and FTIR analyses demonstrated that E,E-2,4-heptadienal spontaneously bound to PLvPs primarily via van der Waals forces and hydrogen bonding. This binding induced conformational changes in PLvPs, which were found to enhance the susceptibility of E,E-2,4-heptadienal to ALDH-mediated degradation. Subsequent ALDH treatment significantly improved the binding capacity of the complexes (by 13.21-78.18%) and largely restored the functional and structural integrity of PLvPs. Molecular dynamics and docking simulations further supported that E,E-2,4-heptadienal binding to PLvPs facilitates ALDH catalysis via these conformational alterations. This study highlights the crucial role of ALDH-mediated oxidative catalytic degradation in modulating the flavor-binding capacity of PLvPs, offering a novel enzymatic strategy for targeted off-flavor elimination and enhancing the sensory quality and industrial utility of liver-based products.

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.

The unique luminescence band of the phosphorus-related bismuth active centre (BAC-P) in bismuth-doped optical fibre is of interest to the development of ultra-broadband optical communication systems. However, the fundamental issues, such as oxidation states and coordination environments of bismuth in this centre, are still unclear. The amorphous nature of BDF, resulting in diverse local environments, presents significant challenges to studying the structure of BAC-P. We comprehensively studied a set of potential and typical structure models using first-principles calculation methods for BAC-P. These models involve bismuth with different valence states, substitutional or interstitial positions, and local environments. Based on the comparison between simulated and experimental energy level diagrams, we have identified that the substitutional Bi1+ in the P-substituted 5-member ring is the likely structure of the BAC-P.

Olfactory receptors (ORs) form the largest superfamily of G protein-coupled receptors (GPCRs). Traditionally recognized for their role in the nasal olfactory epithelium, where they mediate the sense of smell, accumulating evidence has firmly established their ectopic expression in non-olfactory tissues, including the intestine, lungs, and kidneys. The intestine, as the primary site for nutrient digestion and absorption, harbors a highly complex chemical environment. To adapt to this environment, the gut employs a sophisticated network of "chemosensors" to monitor luminal contents and maintain homeostasis. Among these sensors, intestinal ORs have emerged as crucial functional components, serving as a molecular bridge that connects environmental chemical signals-such as food-derived odorants-to specific physiological responses. This discovery has significantly deepened our understanding of how dietary flavors and compounds influence intestinal physiology at the molecular level. This review systematically summarizes the expression profiles, ligand classification, and biological functions of ORs within the gastrointestinal tract. Studies indicate that intestinal ORs exhibit distinct spatial distribution patterns across different gut segments and display cell-type specificity, particularly within enterocytes and enteroendocrine cells. These receptors function as versatile sensors capable of recognizing a wide variety of ligands, including exogenous dietary components, gut microbiota metabolites such as short-chain fatty acids, and endogenous small molecules like azelaic acid. Upon activation by specific ligands, intestinal ORs trigger intracellular signaling cascades, primarily involving the AC-cAMP-PKA pathway or calcium influx channels. A major focus of this review is to elucidate the molecular mechanisms by which these receptors regulate the secretion of gut hormones. Activation of specific ORs in enteroendocrine cells has been shown to stimulate the release of hormones such as glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and serotonin (5-HT), thereby modulating systemic energy metabolism, glucose homeostasis, and gastrointestinal motility. Furthermore, the review addresses the critical roles of ORs in immune regulation and pathology. Evidence suggests that specific ORs contribute to the maintenance of intestinal immune homeostasis and may offer protection against inflammation. Beyond their involvement in inflammatory responses, ORs such as Olfr78 have been shown to regulate the differentiation and function of intestinal endocrine cells. Similarly, Olfr544 has been demonstrated to alleviate intestinal inflammation by remodeling the gut microbiome and metabolome. These findings collectively suggest that specific ORs hold promise as therapeutic targets for mitigating intestinal inflammation and maintaining gut homeostasis. Additionally, the review explores the emerging role of ORs in cancer. Although OR expression is often downregulated in tumor tissues compared to normal mucosa, activation of specific ORs by certain ligands can inhibit tumor cell proliferation and migration and induce apoptosis via pathways such as MEK/ ERK and p38 MAPK. Conversely, other receptors, such as OR7C1, may serve as biomarkers for cancer-initiating cells. In conclusion, intestinal ORs represent a vital component of the gut's sensory network. The review also discusses the translational potential of these findings. By elucidating the precise pairing relationships between dietary components and specific ORs, novel therapeutic strategies could be developed. Intestinal ORs may thus emerge as promising targets for nutritional and pharmacological interventions in metabolic diseases, inflammatory bowel diseases, and malignancies.

Electrochemiluminescence (ECL) intensity is simultaneously influenced by both the electron-transfer and mass transport processes. However, the current concerns with ECL amplification focus on either electron transfer or ion transport. In this contribution, luminol-dissolved O2 ECL amplification from coupled electron and ion transport properties of conductive polymers (CPs) was investigated in detail by employing poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as a model CP. The anodic ECL of luminol-dissolved O2 at a PEDOT:PSS-modified indium tin oxide (ITO) electrode exhibited a 15-fold signal amplification in comparison to that of bare ITO. Further mechanistic investigations revealed that PEDOT could facilitate the electron-transfer process and promote both the conversion of O2 into superoxide radicals and the transition of luminol anions to anion radicals. Additionally, the porous structure and electrochemical doping of the swollen PEDOT:PSS film enabled the transport of luminol anions, synergistically increasing the ECL intensity. This work provides a basis for designing CP-based ECL amplification platforms by leveraging the coupled electron and ion transport to govern ECL emission in the luminol-dissolved O2 system.

The interaction between rice proteins and aroma compounds plays an important role in determining the flavor of rice-based products. However, the effects of different heat treatment modes and temperatures on these interactions remain unclear. This study investigated the influence of pre-heat and co-heat treatments at different temperatures on the binding behavior between rice glutelin and four representative aromas (hexanal, 1-octen-3-ol, methyl heptenone, and 2-pentylfuran). The adsorption and binding abilities of glutelin to aroma increased with increasing temperature. The effect of co-heat treatment on glutelin adsorption capacity was significantly stronger than that of pre-heat treatment. Compared to other aromas, heat treatment had a limited effect on increasing the adsorption capacity of 1-octen-3-ol. Under pre-heat treatment, the depolymerization and degradation of glutelin resulted in the exposure of internal hydrophobic sites and an increase in charge, which promoted the combination of aroma. When glutelin and aroma compounds were co-heat treated, glutelin increased the binding of aroma compounds again because of the influence of heat treatment on the basis of pre-binding aroma. Based on the changes in the structural characteristics of glutelin under spectral analysis and the visualization results of computer simulation calculations, the binding region, interaction force strength, and binding sites of aroma and glutelin under the two heat treatment modes were significantly different. Overall, co-heat treatment represents a more effective thermal strategy for enhancing glutelin-aroma affinity. These findings offer new insights into the regulation of thermal flavor in rice protein products and provide guidance for improving the flavor quality of rice products.

Rapid and sensitive detection of volatile compounds in complex matrices remains challenging due to limited ionization efficiency. Herein, we developed a novel hybrid ionization source by coaxially integrating low-temperature plasma with desorption electrospray ionization (LTP-DESI). The LTP-DESI hybrid source was equipped with a triple quadrupole mass spectrometer to analyze volatile aroma compounds. Under the LTP-DESI mode, volatile aroma compounds exhibited significant signal enhancements, with intensities increased by up to 2 orders of magnitude compared with DESI or LTP. This enhancement arises from a three-stage synergistic mechanism: (1) droplet and plasma-driven desorption, (2) primary ionization by both charged droplets and plasma species, and (3) synergistic ionization enhancement via plasma-droplet interaction. The spatial and temporal overlap of the charged droplet and plasma plume significantly promotes [M + H]+ generation through Penning ionization, proton transfer and charge exchange under atmospheric pressure. The quantitative and qualitative capability of the LTP-DESI-MS platform was validated through analyses of commercial perfumes and banana tissues, achieving recoveries of 75.3-108.5% with relative standard deviations of 2.7-17.1%. These results highlight the potential of the LTP-DESI system as a robust, practical technique for rapid ambient analysis of aromas in diverse complex samples.

BACKGROUND:It is well known that e-cigarette regulations can be developed with the aid of focusing on nicotine flux (NF) and nicotine delivery stability (NDS), which are defined as the amount of nicotine released per puff under given conditions (vape + recipe). In this study, a convenient and fully automated puff-by-puff aerosol nicotine flux measurement method was developed by combining automatic smoking, spectroscopic rapid detection and fiber-optic sensing (AS/SRD/FOS) technology. Aerosol generated by an e-cigarette was introduced into an "impinger", at the meantime, nicotine was trapped in pure water. After the solution was stable, immediate spectral detection at full wavelength (200-600 nm) was accomplished. Depending on a dual-wavelength method or a coefficient ratio method, the absorption value of nicotine in solution was measured. Finally, nicotine amounts were calculated puff-by-puff. RESULTS:The method successfully realized the accurate detection of nicotine flux with low quantification limits (7.1 μg mL-1). Meanwhile, the method has high stability and reproducibility (RSD <10 %), and is suitable for monitoring the NF and NDS. SIGNIFICANCE:It has great potential for application in the evaluation of nicotine delivery efficiency. It fills the gap in the field of nicotine flux stability measurement and meets the monitoring needs of the industry and quality control for nicotine flux stability of e-cigarettes.

Astringency is closely associated with polyphenols found in food and beverages. Given their importance to both the food industry and human health, accurate detection of polyphenols has become a focal point of research. In this study, a dual-mode probe was constructed for polyphenol detection by colorimetry alongside surface-enhanced Raman scattering (SERS). The probe is core-molecule-shell gold/4-MBA/silver nanorods (Au@M@Ag NRs). The silver shell on the surface of Au@M@Ag NRs can be etched by hydrogen peroxide (H2O2), resulting in a significant red-shift in UV absorption spectra and a marked decrease in SERS signal output from 4MBA. Upon introducing polyphenols with strong antioxidant properties, the etching process of the silver shell is inhibited, thereby protecting the shell-core ratio of Au@M@Ag NRs. This process can be readily monitored through both colorimetry and SERS analysis. In our work, harnessing the anti-etching effect exhibited by kaempferol, a type of polyphenol, our dual-mode sensor demonstrates superior detection limits (43.2 nM for colorimetry and 0.786 nM for SERS) compared to previously reported methods. We successfully distinguished five different polyphenols with varying antioxidant capacities: chlorogenic acid, epicatechin, epigallocatechin gallate, kaempferol, and tannic acid through linear discriminant analysis (LDA). This dual-mode sensor can decrease false-positive results while offering promising applications for determining and identifying polyphenols within complex food samples.

Cinnamaldehyde (CA) is the characteristic flavor compound of cinnamon, and the high volatility and instability limit its application in food and flavor industries. This study utilized the reversible self-assembly characteristics of Marsupenaeus japonicus ferritin (MjFer) to encapsulate CA within ferritin nanocages, constructing MjFer and CA complex (MjFer-CA). CA could be successfully encapsulated in ferritin cage with an encapsulation efficiency of 22.77 ± 0.74 % with an applying molar ratio of 1:80 (MjFer/CA). MjFer-CA maintained a homogeneous and globular morphology with a diameter of 15.32 nm. Compared to CA, the encapsulated CA within MjFer-CA displayed enhanced thermal stability (40 °C, 60 °C, and 80 °C), photostability (natural and UV light), and storage stability (4 °C and 25 °C). Moreover, electronic nose, GC-MS, and sensory evaluation analyses confirmed the protective effect of ferritin on CA. This investigation proposes ferritin as a promising delivery system for volatile flavor compounds, offering a novel strategy for flavor preservation.

The ferritin (FRT) with a modifiable cavity can interact with the lysozyme (LYS) to form a heteroprotein complex coacervation (HPCC). This interaction is believed to combine the unique properties of FRT and LYS to form a novel structure with enhanced characteristics. The study aimed to explore the pH-dependent complexation between FRT and LYS and evaluate the protective effects of the heteroprotein complex on curcumin (Cur). Results showed that pH and protein ratios influenced the formation of the complex. ζ-potential measurements indicated that interactions between oppositely the charged molecules and hydrogen bonding drove the formation of FRT-LYS (FL) complexes, enhancing their hydrophobicity and thermal stability. Cur-encapsulated in FL (FCL) demonstrated an increased stability when exposed to heat, natural light, and ultraviolet light (FL/Cur, 1:50) treatments, and showed a controlled and sustained release behavior. This study emphasizes the potential of FL heteroprotein complexes as nanocarriers for encapsulation and protection of bioactive molecules.

Bismuth-doped optical fibre (BDF) is a significant potential optical material for optical communication owing to its broad gain spectrum attributed to several bismuth active centres (BACs). In this work, we propose and study a simple model of aluminium-related bismuth active centre (BAC-Al) considering both Al and Bi in a member ring, using first principle methods. We analyse an Al-substituted member-ring with different Bi cases: substituted Bi1+, Bi2+ and Bi3+ as well as interstitial Bi0, BiO, BiOH, and Bi2O, and found that the interstitial Bi0 model produces the energy level diagram similar to that of BAC-Al. In addition, we studied the interstitial Bi0 in Al-substituted member-rings with different sizes and shapes. Based on our results, we confirmed that the interstitial Bi0 in an Al-substituted six-member-ring produces the best agreement in terms of BAC-Al energy level diagram.

In this work, we propose and demonstrate a novel approach to suppressing stimulated Raman scattering in an oscillating–amplifying integrated fiber laser (OAIFL) by changing the spectral bandwidth of the output-coupler fiber Bragg gratings (OC-FBGs). The reflectance bandwidth of the fiber Bragg grating (FBG) in the oscillating section was systematically investigated as a critical parameter for SRS mitigation. Three types of long-period FBGs with distinct reflectance bandwidths (1.2 nm, 1.3 nm, and 2 nm) were comparatively studied as output couplers. The experimental results demonstrated a direct correlation between FBG bandwidth and SRS suppression efficiency, with the configuration of the OC-FBG with a 2 nm bandwidth achieving optimal suppression performance. Concurrently, the output power was enhanced to 5.02 kW with improved power scalability. And excellent beam quality was obtained with M2 < 1.3. Remarkably, in the architecture of this laser, increasing the bandwidth of the output couplers in the oscillating section had a relatively minor effect on the optical-to-optical (O-O) efficiency, which reached up to 78%. Additionally, this modification also reduced the 3 dB bandwidth of the laser output, thereby achieving a beam output with enhanced monochromaticity.

The processing technique critically determines the quality of prepackaged braised meat products. This study aimed to evaluate the effects of an innovative processing method against traditional methods on the product’s shelf-life and quality attributes. Results: no significant difference in shelf-life was observed between the experimental and control groups. However, the innovative method significantly improved product quality. The experimental group exhibited a redder and bluer color, significantly higher hardness (2–4 times, p < 0.01) and chewiness, alongside better moisture retention and meat yield. Sensory evaluation confirmed an overall preference for the experimental group (p < 0.05). Flavor profile analysis revealed a greater number and more stable retention of key flavor compounds (alcohols, ketones, and ethers) in the experimental group. The innovative processing method optimizes traditional techniques by significantly enhancing the physicochemical, textural, sensory, and flavor properties of prepackaged braised meat, without compromising shelf-life, providing a novel strategy for producing high-quality products.

Sweetening compounds are commonly incorporated into food products to enhance their texture and flavor, thereby indicating product quality. 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) is a sweet aromatic compound characterized by its pineapple-like baking scent. While it serves as a taste enhancer in various industries, including wine production and soy sauce manufacturing, HDMF also exhibits DNA-damaging activity in foods. In this study, a fluorescence detection method based on fluorescence resonance energy transfer (FRET) for the sensitive detection of HDMF was developed. Initially, gold nanoparticles were deposited onto the surface of Fe3O4 to create fluorescence-quenching materials. Subsequently, thiol-functionalized β-cyclodextrin (SH-β-CD) was modified to provide cavities that allow the fluorescent dye rhodamine 6G (R6G) to enter. The fluorescence of R6G remains quenched until HDMF is present because it will compete with R6G for binding sites within the SH-β-CD cavities through competitive host–guest recognition. Furthermore, the fluorescence intensity of R6G at 553 nm exhibited a strong linear correlation with the logarithmic value of HDMF concentration over a range from 5 × 10−7 M to 10−4 M. This rapid and sensitive fluorescence detection strategy rooted in FRET and competitive host–guest recognition demonstrated significant potential for detecting HDMF in food products.

Alzheimer's disease (AD) presents significant challenges due to its intricate pathogenic mechanisms and the limited efficacy of single-target therapies. In this study, we investigated the potential of chlorogenic acid (CHA), a multifunctional natural active compound, in AD therapy by developing a trifunctional nanocarrier (MC-H/R/si). CHA was effectively conjugated with iron-based metal-organic frameworks (MIL/Fe-100) through chelation interaction. The resulting nanocomplex (MC) not only enhances the bioavailability of CHA but also facilitates a synergistic antioxidant effect between CHA and MIL/Fe-100. Importantly, CHA can chelate Zn2+ from β-amyloid/Zn2+ (Aβ/Zn2+) polymers, inhibiting Aβ aggregation. Furthermore, small interfering RNA targeting BACE1 was covalently linked to MC to downregulate BACE1 expression. Both in vitro and in vivo experiments revealed that MC-H/R/si effectively scavenges ROS, reduces inflammation and Aβ plaque, and improves the learning and cognitive abilities of APP/PS1 mice. These findings confirm that the trifunctional nanocarrier MC-H/R/si has great potential for AD treatment.