Search Results (324)

Temperature is the most critical factor in fish preservation. Superchilled storage represents a novel technology that effectively retards quality deterioration in aquatic products. This study investigated the flavor variation patterns and deterioration mechanisms in 16 northern pike (Esox lucius) samples during superchilled storage (−3 °C) based on analysis using gas chromatography-ion mobility spectrometry (GC-IMS) and ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). The results indicate that GC-MS analysis identified 25 key volatile flavor compounds. These comprised seven ketones, thirteen alcohols, aldehydes including 2-methylbutanal, esters such as 2-heptyl acetate and methyl butyrate, as well as nitrogen-containing compounds, exemplified by pyrazines and indole. Non-targeted metabolomics further revealed four pivotal metabolic pathways, glycerophospholipid metabolism, purine metabolism, the pentose phosphate pathway, and arginine biosynthesis. These metabolic pathways were found to regulate flavor changes through modulation of lipid oxidation, nucleotide degradation, and amino acid metabolism. Notably, the arginine biosynthesis pathway exhibited significant correlations with the development of characteristic cold-storage off-flavors, mediated by glutamate accumulation and fumarate depletion. This investigation provided a theoretical foundation for optimizing preservation strategies in cold-water fish species at the molecular level. Full article

Polyfluoroalkyl substances (PFASs) and para-phenylenediamines (PPDs) are emerging classes of anthropogenic contaminants that are environmentally persistent (most often found in ground and surface water sources), bioaccumulative, and harmful to human health. These chemicals are currently regulated in the US by the Environmental Protection Agency (EPA), the Food and Drug Administration (FDA), and the Occupational Safety and Health Administration (OSHA). Analysis of these contaminants is currently spearheaded by mass spectrometry (MS) coupled to liquid chromatography (LC) because of their high sensitivity and separation capabilities. Although effective, a major flaw in LC-MS analysis is its large consumption of solvents and the amount of time required for each experiment. Direct analysis in real time mass spectrometry (DART-MS) is a new technique that offers high sensitivity and permits rapid analysis with little to no sample preparation. Herein, we present the qualitative and quantitative analysis of PFASs and PPDs by high-resolution DART-MS, interfaced with ion mobility (IM) and tandem mass spectrometry (MS/MS) characterization, demonstrating the utility of this multidimensional approach for the fast separation and detection of environmental contaminants. Full article

Compound Glycyrrhizin tablets (CGTs) are a combination of glycyrrhizin, glycine and methionine. Glycine and methionine have relatively high polarity and lack chromophore; therefore, it is difficult to simultaneously determine the various components using traditional reversed-phase chromatography and ultraviolet detectors. In addition, it is even more challenging to obtain a comprehensive and systematic impurity profiling for the CGTs. In this study, an ion-pair high-performance liquid chromatography (HPLC)–charged aerosol detection (CAD) method was established to determine the content of glycyrrhizin, glycine and methionine. The impurities of CGTs were also identified using mass spectrometry. By optimizing the content of trifluoroacetic acid (TFA) in the mobile phase and optimizing the CAD parameter settings, the developed method was verified in accordance with the guidelines outlined in ICH Q2 (R2). The results indicated that the method demonstrated high accuracy and sensitivity. Glycine, methionine and glycyrrhizin all showed a good linear relationship within the labeled range of 50–200%, and the average recoveries of the three components were 97.62–100.6%. The impurity detection was quantified via the principal component control method. The limit of detection (LOD) method showed an equivalent to 0.05% of the glycyrrhizin in CGTs, approximately 12.5 ng. The ion-pair HPLC–CAD method developed in this study simultaneously determined the content of the main component and the impurities of CGTs, without necessitating derivatization. This has provided a research basis for further improving the quality standards of CGTs. Full article

To explore the influence of cooking methods on the flavor parameters of Tibetan sheep, various techniques such as atmospheric-pressure (AP), high-pressure (HP), atmospheric-pressure high-pressure (APHP), and high-pressure atmospheric-pressure (HPAP) cooking were tested. The results indicated that APHP and HP cooking yielded the best sensory qualities, accounting for 26.15% and 25.51%, respectively. The HP group had the highest amino acid content at 34%, enhancing the meat’s sweet taste due to alanine, glycine, arginine, and methionine. Among 40 detected fatty acids, the order of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), and n-6/n-3 content was AP > APHP > HPAP > HP (p < 0.05). An electronic tongue and nose identified aroma components across the four cooking methods. Similarities in aroma were observed among the samples after cooking, while significant differences were found in the aroma components between the AP group and the other three cooking methods (p < 0.05). The gas chromatography–ion mobility spectrometry (GC–IMS) and gas chromatography–mass spectrometry (GC–MS) analyses of the meat in the four groups indicated that there were significant differences in volatile compounds among meat cooked with different methods (p < 0.05), with 56 and 365 flavor compounds detected by the two analytical techniques, respectively. Moreover, the GC–MS results indicated that the flavor substance content in the HP group accounted for 30.80% among these four sample groups. This comprehensive analysis showed that high-pressure steaming could significantly improve the flavor quality of Tibetan sheep, providing a theoretical basis and empirical reference for the optimization of pre-treatment conditions and the processing of Tibetan sheep. Full article

Background/Objectives: D-lysergic acid diethylamide (D-LSD) is under investigation as a potential therapeutic strategy for alcohol use disorder (AUD). However, the extreme light sensitivity of D-LSD presents a significant challenge in developing suitable pharmaceutical forms, particularly for clinical trial settings. This study proposes a liquid-filled capsule formulation designed to provide accurate dosing while protecting D-LSD from photodegradation. Methods: To support formulation development and ensure its suitability as an investigational medicinal product, a multi-tiered analytical strategy was employed. This included liquid chromatography coupled with ion mobility spectrometry and mass spectrometry (LC-IM-MS), along with quantum chemical calculations (density functional theory (DFT) and time dependent-DFT (TD-DFT)), to ensure robust and orthogonal structural characterization of degradation products. Results: Photostress studies demonstrated that while D-LSD in solution rapidly degrades into photoisomers and photooxidative byproducts, the capsule formulation markedly mitigates these transformations under ICH-compliant conditions. Conclusions: These findings highlight the essential role of orthogonal stability profiling in guiding formulation development and demonstrate that this approach may offer a viable, photostable platform for future clinical investigation of D-LSD in the treatment of AUD. Full article

Background/Objectives: In the context of accelerating climate change and growing food insecurity, improving crop resilience to abiotic stresses such as drought, salinity, heat, and cold is a critical agricultural and scientific challenge. Understanding the biochemical mechanisms that underlie plant stress responses is essential for developing resilient crop varieties This review aims to provide an integrative overview of how metabolomics can elucidate biochemical mechanisms underlying stress tolerance and guide the development of stress-resilient crops. Methods: We reviewed the recent literature on metabolomic studies addressing abiotic stress responses in various crop species, focusing on both targeted and untargeted approaches using platforms such as nuclear magnetic resonance (NMR), liquid chromatography–mass spectrometry (LC-MS), and gas chromatography–mass spectrometry (GC-MS). We also included emerging techniques such as capillary electrophoresis–mass spectrometry (CE-MS), ion mobility spectrometry (IMS-MS), Fourier transform infrared spectroscopy (FT-IR), and data-independent acquisition (DIA). Additionally, we discuss the integration of metabolomics with transcriptomics and physiological data to support system-level insights. Results: The reviewed studies identify common stress-responsive metabolites, including osmoprotectants, antioxidants, and signaling compounds, which are consistently linked to enhanced tolerance. Novel metabolic biomarkers and putative regulatory hubs are highlighted as potential targets for molecular breeding and bioengineering. We also address ongoing challenges related to data standardization and reproducibility across analytical platforms. Conclusions: Metabolomics is a valuable tool for advancing our understanding of plant abiotic stress responses. Its integration with other omics approaches and phenotypic analyses offers promising avenues for improving crop resilience and developing climate-adaptive agricultural strategies. Full article

Chiral analysis is becoming increasingly important across various scientific fields, including chemistry, pharmaceuticals, biosciences, and more recently, metabolomics. In this context, a high-resolution and high-throughput method was developed for the simultaneous determination of the enantiomeric ratio (er) of seven pairs of amino acid (AA) enantiomers (Arg, Gln, His, Met, Pro, Tyr, and Trp) using flow injection analysis coupled with ion mobility-mass spectrometry (FIA-IM-MS) technology. Specifically, the Single Ion Mobility Monitoring (SIM²) mode on a TIMS-Tof^TM instrument enabled the rapid relative quantification of chiral compound mixtures. A linear model accurately described the relationship between enantiomeric ratio and IM-MS response for Arg, Gln, and Pro enantiomers, as evidenced by high R² values and unbiased residuals. In contrast, non-linear trends were observed for His, Tyr, and Trp, where a quadratic model significantly improved the fit. However, the linear model was retained for Met, despite an R² of about 0.98, due to its comparable performance and simplicity. Measurement accuracy was confirmed with very good recovery rates for er values of 0.95 and 0.99 across all AAs. Finally, the potential of the FIA-SIM²-MS approach in chiral analysis was demonstrated, particularly its ability to provide a reliable and efficient high-throughput tool for accurate er determination. Full article

Drug conjugates, in which chemotherapeutic or cytotoxic agents are coupled to targeting or delivering macromolecules like peptides or proteins via a linker, revolutionize cancer treatment. While protein-drug and antibody-drug conjugates have already secured a role in clinical oncology, peptide–drug conjugates (PDCs) are emerging as a promising alternative, offering enhanced efficacy and fewer side effects compared to the free drug molecules. Comprehensive chemical and biological investigation of PDCs is crucial during drug development and optimization, paving the way for the next generation of targeted therapies. Anthracycline-containing peptide conjugates have emerged as promising candidates in targeted cancer therapies due to their ability to deliver cytotoxic agents directly to tumor cells. However, their structural complexity poses significant analytical challenges, particularly in mass spectrometric characterization. Accurate identification and quantification of these conjugates are critical for assessing their stability, efficacy, and mechanism of action. This article explores the major difficulties encountered during mass spectrometry (MS) analysis of anthracycline-peptide conjugates, focusing on ionization issues, fragmentation behavior, and challenges of detection from biological matrix. Full article

The structural analysis of glycans remains a major challenge due to their high isomeric complexity and conformational flexibility arising from diverse glycosidic linkages and dynamic three-dimensional structures. Ion mobility–mass spectrometry (IM–MS) has been attracting attention as a way to develop the structural analysis of glycans. In this study, the effects of ionization conditions—including different types of adduct ions, ionization temperatures, and solvent environments—on the ion mobility behavior of glycans were systematically investigated. IM–MS measurements of ethylamine-tagged glycans showed broad arrival time distributions of monoprotonated ions indicating the presence of multiple conformers of glycans. Increased ionization temperatures and the use of methanol as a solvent further broadened the distribution, suggesting the enhanced conformational dynamics of the glycan ions. In contrast, sodium adduct ions yielded narrower distributions, implying that the interactions between sodium ions and glycans constrained structural flexibility. These results demonstrate that ionization parameters have a significant impact on glycan conformational behavior and mobility in the gas phase. This study provides insights into the analytical conditions for IM–MS measurements of glycans and highlights the utility of this method as a powerful tool for elucidating glycan structure and dynamics. Full article

Background: This study presents a sensitive method for the simultaneous determination of organic acids, flavonoids, and amino acids in Mume Fructus (MF) using ultra-performance liquid chromatography coupled with triple-quadrupole linear ion-trap tandem mass spectrometry (UPLC-QTRAP-MS/MS). Methods: Analysis was performed on a UPLC system (Shimadzu, Kyoto, Japan) equipped with a quaternary pump solvent management system, an online degasser, a triple-quadrupole mass detector, and an autosampler. An Agilent ZORBAX SB-C18 column (3.0 mm × 100 mm, 1.8 µm) was used for chromatographic analyses. The mobile phase was distributed between 0.2% aqueous formic acid (A) and 0.2% formic acid acetonitrile (B) at a velocity of 0.2 mL/min. The gradient evolution protocol was 0–2 min at 90–70% B; 3–7 min at 70–50% B; 7–10 min at 50–20% B; 10–14.5 min at 20–90% B; and 14.5–17 min at 10% B. Results: The method was validated for matrix effects, linearity, limits of detection/quantification, precision, repeatability, stability, and recovery of target components. It effectively determined all target compounds in 12 MF batches from different drying methods. Conclusions: Principal component analysis (PCA) of 47 active components was conducted to evaluate MF quality comprehensively. The proposed method serves as a reliable approach for assessing the consistency of MF’s quality and therapeutic efficacy. Full article

Herein, Elaeagnus angustifolia L. was utilized as a raw material to extract bound polyphenols using an ultrasound-assisted complex enzyme method for the first time. The effects of enzyme ratio, ultrasonic time, liquid-to-solid ratio, and pH value on the bound polyphenol yield were investigated using single-factor experiments. The key parameters were subsequently optimized using the Box–Behnken design. The optimal conditions identified were as follows: enzyme ratio (α-amylase/cellulase = 5:1 mg/mg), ultrasonic time of 50 min, liquid-to-solid ratio of 12:1 mL/g, and pH value of 5. Under these conditions, the bound polyphenol yield was measured at 13.970 ± 0.3 mg/g. A total of 27 phenolic compounds were identified using ultrahigh-performance liquid chromatography–ion mobility quadrupole time-of-flight mass spectrometry (UPLC–IMS-QTOF-MS), including two coumarins, five lignins, 10 polyphenols, nine flavonoids, and one tannin, and specifically containing Angeloylgomisin Q, Yakuchinone A, Furosin, 6-Dehydrogingerdione, and 4′-Methylpinosylvin, and so on. Antioxidant activity was assessed using the 1,1-diphenyl-2-picryl-hydrazil (DPPH) and 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) methods, revealing significant antioxidant potential. This study introduced a novel extraction process for bound polyphenols from E. angustifolia L. and provided the first qualitative analysis of bound polyphenols in this species, establishing a scientific foundation for its development and application in the functional food, medicine, and cosmetics industries. Full article

As a culturally iconic Chinese delicacy, pufferfish lacks systematic research on thermal processing optimization and pre-cooked meal development, limiting its industrial standardization and quality preservation. This study aimed to bridge this gap by evaluating steaming effects on Takifugu flavidus quality. This study systematically evaluated its physicochemical properties and flavor profiles under different steaming durations by determining the water loss rate, mass loss rate, water distribution status, textural properties, color, and free amino acid content using an electronic nose, electronic tongue, and headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS). The results indicated that the core temperature of the fish meat reached 70 °C after 9 min of steaming. With higher steaming time, its mass loss rate and water loss rate generally increased, though the water loss rate temporarily decreased at 10 min. The mass loss rate stabilized after 12.5 min. The hardness and chewiness of the fish meat increased significantly when steamed for 12.5 min or longer. After 5 min of steaming, the brightness value and yellow-blue value of the fish meat significantly increased, whereas the red-green value significantly decreased. The total free amino acid content showed a fluctuating upward trend and electronic tongue analysis revealed an increase in umami and richness after steaming. Electronic nose and HS-GC-IMS analyses demonstrated that the variety and content of volatile flavor compounds significantly increased with prolonged steaming. Sensory evaluation showed that the 10 min steaming group exhibited better texture and color, while the 15 min steaming group had the best odor. Therefore, the optimal steaming time for T. flavidus was determined to be 10–15 min. For home cooking, a 15 min steaming process achieves the peak abundance of flavor compounds and the highest sensory evaluation score. For the industrial production of pre-cooked meals, a 10 min steaming process can meet the doneness requirements while maintaining suitable textural properties and color stability. The findings of this study not only advance the scientific understanding of thermal processing effects on pufferfish quality attributes, but also establish a critical technological foundation for developing standardized industrial processing protocols and high-quality pre-prepared pufferfish products. Full article

To investigate the impact of varying steaming durations on the flavor characteristics of mutton and carrot stuffing, dynamic changes in volatile organic compounds (VOCs) and fatty acids were analyzed using solid-phase micro-extraction gas chromatography–mass spectrometry (SPME-GC-MS) and gas chromatography–ion mobility spectrometry (GC-IMS). The results revealed a total of 116 VOCs identified throughout the steaming process, with 73 detected by GC-MS and 44 by GC-IMS. Notably, VOC concentrations were significantly higher at 18–24 min compared to 8–16 min. Additionally, a GC-IMS fingerprint was developed to assess the distribution of VOCs during steaming. Orthogonal partial least squares discriminant analysis (OPLS-DA) indicated that 11 compounds, such as ethyl caprylate (B3), linalyl acetate (B6), and 1-nonanal (C1), significantly influenced the flavor characteristics of the mutton and carrot filling. Further analysis demonstrated that stearic acid content reached its lowest point at 20–22 min of steaming, while n-6 and n-3 series polyunsaturated fatty acids (PUFAs) and the ratio of polyunsaturated fatty acids to saturated fatty acids (P/S) peaked at this time. Full article

Many scholars have studied Tricholoma matsutake soup, but there are relatively few studies exploring the aroma changes during its cooking process using different detection methods. The aroma of T. matsutake soup was analyzed and compared using electronic nose (E-nose) analysis, headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), and headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). A significant effect of cooking time on the overall aroma profile of T. matsutake soup was identified through E-nose analysis. By HS-GC-IMS and HS-SPME-GC-MS analysis, 51 volatile aroma compounds were detected, with alcohols and aldehydes identified as the main aroma substances. Based on the relative odor activity value (ROAV) and multivariate statistical analysis, 1-octen-3-ol, 1-octanol, methyl cinnamate, and 2-pentyl furan were determined to be the key aroma compounds in the cooking process. We observed that shorter cooking time preserved the mushroom aroma of T. matsutake soup most effectively. These findings can be utilized for the industrial production of T. matsutake soup and for optimization of its key aroma components. Full article

Mulberry leaves contain polysaccharides, phenols, alkaloids, and other active ingredients which have medicinal and edible value. In this study, fermented mulberry leaf powder was prepared by solid-state fermentation using Pediococcus pentosaceus JC30. The effects of the fermentation on the phytochemical, flavor characteristics, phenolics, and antioxidant activity of mulberry leaves were studied. The results showed that the content of γ-aminobutyric acid in fermented mulberry leaf powder (FMLP) increased by 6.73-fold and the content of phytic acid decreased by 11.16%. Ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) analysis showed that the fermentation of Pediococcus pentosaceus JC30 altered the phenolic composition of mulberry leaves, increasing the total free phenolic content by 88.43%. In particular, the contents of free phenols such as leucocyanidin, myricetin, and quercetin increased significantly and were positively correlated with antioxidant capacity. The fermentation of Pediococcus pentosaceus JC30 significantly enhanced the scavenging ability of DPPH free radicals, hydroxyl radicals, and the total reducing ability of mulberry leaves. Gas chromatography ion mobility spectrometry (GC-IMS) analysis showed that FMLP has an intense fruity and floral aroma, while having less grassy and earthy odor. The fermentation improved the phytochemical, flavor, and nutritional value of mulberry leaves, which provides more possibilities for the development of mulberry leaf products outside the sericulture industry. Full article