Spatial Omics Reveals that Cancer-Associated Glycan Changes Occur Early in Liver Disease Development in a Western Diet Mouse Model of MASLD.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a progressive disease and comprises different stages of liver damage; it is significantly associated with obese and overweight patients. Untreated MASLD can progress to life-threatening end-stage conditions, such as cirrhosis and liver cancer. N-Linked glycosylation is one of the most common post-translational modifications in the cell surface and secreted proteins. N-Linked glycan alterations have been established to be signatures of liver diseases. However, the N-linked glycan changes during the progression of MASLD to liver cancer are still unknown. Here, we induced different stages of MASLD in mice and liver-cancer-related phenotypes and elucidated the N-glycome profile during the progression of MASLD by quantitative and qualitative profiling in situ using matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS). Importantly, we identified specific N-glycan structures including fucosylated and highly branched N-linked glycans at very early stages of liver injury (steatosis), which in humans are associated with cancer development, establishing the importance of these modifications with disease progression. Finally, we report that N-linked glycan alterations can be observed in our models by MALDI-IMS before liver injury is identified by histological analysis. Overall, we propose these findings as promising biomarkers for the early diagnosis of liver injury in MASLD.

Aromaticity in Semi-Condensed Figure-Eight Molecules.

Electron delocalization and aromaticity was comparatively evaluated in recently synthesized figure-eight molecules made of two condensed U-shaped polycyclic aromatic hydrocarbon moieties connected either by two single bonds or by two para-phenylene groups. The selected examples include molecules that incorporate eight-membered and sixteen-membered rings, as well as a doubly [5]helicene-bridged (1,4)cyclophane. We probe whether some electron delocalization could occur through the stereogenic single bonds in these molecules: Is aromaticity purely (semi-)local, or possibly also global in these molecules? It was concluded that the situation can go from a purely (semi-)local character when the dihedral angle at the connecting single bonds is large, such as in biphenyl, to a predominantly (semi-)local character with a minor global contribution when the dihedral angle is small, such as in the para-phenylene connectors of the [5] helicene-bridged cyclophane.

Validation of the Individualized Metabolic Surgery score in predicting long-term remission of diabetes after duodenal switch-type procedures.

AIM: To validate the Individualized Metabolic Surgery (IMS) score and assess long-term remission of type 2 diabetes (T2D) after duodenal switch (DS)-type procedures in patients with obesity. In addition, to help guide metabolic procedure selection for those patients categorized as having severe T2D. MATERIALS AND METHODS: This is a retrospective single cohort study of all patients with T2D and severe obesity, who underwent DS-type procedures at a single institution from December 2010 to December 2018. Study endpoints included validating the IMS score in our cohort and evaluating the impact of DS-type procedures on long-term (≥ 5 years) remission of T2D, especially in patients with severe disease. A receiver operator characteristic curve was used to assess the accuracy of the IMS score using the area under the curve (AUC). RESULTS: The study cohort included 30 patients with complete baseline and long-term glycaemic data after their index DS-type surgery. Twelve patients (40%) were classified with severe T2D, and the distribution of IMS-based severity groups was similar between our cohort and the original IMS study (P = .42). IMS scores predicted long-term T2D remission with AUC = 0.77. Patients with IMS-based severe diabetes achieved significantly higher long-term remission after DS-type procedures compared with gastric bypass and/or sleeve gastrectomy from the original IMS study (42% vs. 12%; P < .05). CONCLUSIONS: The IMS score properly classifies the severity of T2D in our study cohort and adequately predicts its long-term remission after DS-type procedures. While T2D remission decreases with more severe IMS scores, long-term remission remains high after DS-type procedures among patients with severe disease.

Comparison of direct analysis in real-time mass spectrometry, atmospheric solids analysis probe-mass spectrometry, and ion mobility spectrometry for ensuring food safety by rapid screening of poppy seeds.

The opium poppy (Papaver somniferum) is a global commercial crop that has been historically valued for both medicinal and culinary purposes. Naturally occurring opium alkaloids including morphine, codeine, thebaine, noscapine, and papaverine are found primarily in the latex produced by the plant. If the plant is allowed to fully mature, poppy seeds that do not contain the opium alkaloids will form within the pods and may be used in the food industry. It is possible for the seeds to become contaminated with alkaloids by the latex during harvesting, posing a potential health risk for consumers. In the USA, there have been more than 600 reported adverse events including 19 fatalities that may be linked to the consumption of a contaminated poppy-containing product such as home-brewed poppy seed tea. Unwashed poppy seeds and pods may be purchased over the Internet and shipped worldwide. The Forensic Chemistry Center, US Food and Drug Administration (FDA) has evaluated several mass spectrometers (MS) capable of rapid screening to be used for high-throughput analysis of samples such as poppy seeds. These include a direct analysis in real-time (DART) ambient ionization source coupled to a single-quadrupole MS, an atmospheric solids analysis probe (ASAP) ionization source coupled to the same MS, and ion mobility spectrometers (IMS). These instruments have been used to analyze 17 poppy seed samples for the presence of alkaloids, and the results were compared to data obtained using liquid chromatography with mass spectral detection (LC-MS/MS). Results from the 17 poppy seed samples indicate that the DART-MS, ASAP-MS, and IMS devices detect many of the same alkaloids confirmed during the LC-MS/MS analyses, although both the false-positive and false-negative rates are higher, possibly due to the non-homogeneity of the samples and the lack of chromatographic separation.

Volatile-compound fingerprinting and discrimination of positional isomers in stamp-pad ink tracing using HS-GC-IMS combined with multivariate statistical analysis.

The rising crime rate associated with document forgery has a significant impact on public safety and social stability. In document fraud cases, determining the origin of a particular stamp-pad ink is the most important objective. In this study, a comprehensive analysis of the volatile compounds in quick-drying stamp-pad inks from six commonly used brands were performed for the first time, utilizing a combination of headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and multivariate statistical analysis methods. Visual and comparative analysis of the differential volatile components among different stamp-pad ink samples was conducted using fingerprints and volcano plots. A total of 127 volatile compounds were accurately identified, with ketones, esters, alcohols, and aldehydes being the most abundant compounds in the stamp-pad inks. Hierarchical clustering analysis (HCA), including dendrograms and clustering heatmaps, was utilized to explore the correlations between these compounds and the samples. Additionally, the precise identification of positional isomers and functional group isomers of aliphatic compounds was achieved. To achieve accurate discrimination of various stamp-pad ink samples, a multivariate statistical analysis method was utilized to establish a classification model for them. Based on the results obtained from HS-GC-IMS, effective discrimination among different brands of stamp-pad ink samples was achieved through principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). The model exhibited excellent performance, with the fit index of dependent variables (R2Y) and the predictive index of the model (Q2) values of 0.99 and 0.984, respectively. These results provided significant theoretical evidence for the application of HS-GC-IMS as an efficient technique in the analysis of volatile compounds, identification of positional isomers and functional group isomers, as well as tracing the origin of stamp-pad ink and analyzing the formation time of documents.

Accelerating strain phenotyping with desorption electrospray ionization-imaging mass spectrometry and untargeted analysis of intact microbial colonies.

Reading and writing DNA were once the rate-limiting step in synthetic biology workflows. This has been replaced by the search for the optimal target sequences to produce systems with desired properties. Directed evolution and screening mutant libraries are proven technologies for isolating strains with enhanced performance whenever specialized assays are available for rapidly detecting a phenotype of interest. Armed with technologies such as CRISPR-Cas9, these experiments are capable of generating libraries of up to 1010 genetic variants. At a rate of 102 samples per day, standard analytical methods for assessing metabolic phenotypes represent a major bottleneck to modern synthetic biology workflows. To address this issue, we have developed a desorption electrospray ionization-imaging mass spectrometry screening assay that directly samples microorganisms. This technology increases the throughput of metabolic measurements by reducing sample preparation and analyzing organisms in a multiplexed fashion. To further accelerate synthetic biology workflows, we utilized untargeted acquisitions and unsupervised analytics to assess multiple targets for future engineering strategies within a single acquisition. We demonstrate the utility of the developed method using Escherichia coli strains engineered to overproduce free fatty acids. We determined discrete metabolic phenotypes associated with each strain, which include the primary fatty acid product, secondary products, and additional metabolites outside the engineered product pathway. Furthermore, we measured changes in amino acid levels and membrane lipid composition, which affect cell viability. In sum, we present an analytical method to accelerate synthetic biology workflows through rapid, untargeted, and multiplexed metabolomic analyses.

Membrane-Based Pulsed Sampling Method for Extended Dynamic Range of Ion Mobility Spectrometry.

Ion mobility spectrometry (IMS) has been widely studied and applied as an effective analytical technology for the on-site detection of volatile organic compounds (VOCs). Despite its superior selectivity compared with most gas sensors, its limited dynamic range is regarded as a major drawback, limiting its further application in quantitative measurements. In this work, we proposed a novel sample introduction method based on pulsed membrane adsorption, which effectively enhanced IMS's ability to measure analytes at higher concentrations. Taking N-methyl-2-pyrrolidone (NMP) as an example, this new sampling method expanded the dynamic range from 1 ppm to 200 ppm. The working principle and measurement strategy of this sampling method were also discussed, providing new insights for the design and application of IMS-based instruments.

Research on Image Mapping Spectrometer Based on Ultra-Thin Glass Layered Mapping.

The imaging quality of the Mapping Imaging Spectrometer (IMS) is crucial for spectral identification and detection performance. In IMS, the image mapper significantly influences the imaging quality. Traditional image mappers utilize a single-point diamond machining process. This process leads to inevitable edge eating phenomena that further results in noticeable deficiencies in imaging, impacting spectral detection performance. Therefore, we propose a manufacturing process for the image mapper based on ultra-thin layered glass. This process involves precision polishing of ultra-thin glass with two-dimensional angles, systematically assembling it into an image mapper. The surface roughness after coating is generally superior to 10 nm, with a maximum angle deviation of less than 3'. This results in high mapping quality. Subsequently, a principle verification experimental system was established to conduct imaging tests on real targets. The reconstructed spectrum demonstrates excellent alignment with the results obtained from the Computed Tomography Imaging Spectrometer (CTIS). We thereby validate that this approach effectively resolves the issues associated with edge eating (caused by traditional single-point diamond machining), and leads to improved imaging quality. Also when compared to other techniques (like two-photon polymerization (2PP)), this process demonstrates notable advantages such as simplicity, efficiency, low processing costs, high fault tolerance, and stability, showcasing its potential for practical applications.

Environmental Constraints for Intelligent Internet of Deep-Sea/Underwater Things Relying on Enterprise Architecture Approach.

Through the use of Underwater Smart Sensor Networks (USSNs), Marine Observatories (MOs) provide continuous ocean monitoring. Deployed sensors may not perform as intended due to the heterogeneity of USSN devices' hardware and software when combined with the Internet. Hence, USSNs are regarded as complex distributed systems. As such, USSN designers will encounter challenges throughout the design phase related to time, complexity, sharing diverse domain experiences (viewpoints), and ensuring optimal performance for the deployed USSNs. Accordingly, during the USSN development and deployment phases, a few Underwater Environmental Constraints (UECs) should be taken into account. These constraints may include the salinity level and the operational depth of every physical component (sensor, server, etc.) that will be utilized throughout the duration of the USSN information systems' development and implementation. To this end, in this article we present how we integrated an Artificial Intelligence (AI) Database, an extended ArchiMO meta-model, and a design tool into our previously proposed Enterprise Architecture Framework. This addition proposes adding new Underwater Environmental Constraints (UECs) to the AI Database, which is accessed by USSN designers when they define models, with the goal of simplifying the USSN design activity. This serves as the basis for generating a new version of our ArchiMO design tool that includes the UECs. To illustrate our proposal, we use the newly generated ArchiMO to create a model in the MO domain. Furthermore, we use our self-developed domain-specific model compiler to produce the relevant simulation code. Throughout the design phase, our approach contributes to the handling and controling of the uncertainties and variances of the provided quality of service that may occur during the performance of the USSNs, as well as reducing the design activity's complexity and time. It provides a way to share the different viewpoints of the designers in the domain of USSNs.

The Status Quo of Internet Medical Services in China: A Nationwide Hospital Survey.

Background: Internet medical services (IMS) have been rapidly promoted across China, especially since the outbreak of COVID-19. However, a nationwide study is still lacking. Objective: To unveil the whole picture of IMS across tertiary and secondary hospitals in China, and to evaluate potential influence of the hospital general characteristics, medical staff reserve, and patient visiting capacity on IMS provision. Methods: An online cross-sectional survey was conducted, and 1,995 tertiary and 2,824 secondary hospitals completed questionnaires from 31 administrative regions in China during July 1 and October 31, 2021. Those hospitals are defined having abilities of providing IMS if at least one following service are available: (1) online appointment of diagnoses and treatments; (2) online disease consultation; (3) electronic prescription; and (4) drug delivery. The logistic regression models are used to detect the possible roles on developing IMS. Results: A majority (68.9%) of tertiary hospitals and 53.0% secondary hospitals have provided IMS (p < 0.01). Tertiary hospital also had much higher proportions than secondary hospitals in online appointment of diagnoses and treatments (62.6% vs. 46.1%), online disease consultation (47.3% vs. 16.9%), electronic prescription (33.2% vs. 9.6%), and drug delivery (27.8% vs. 4.6%). In multivariate model, IMS hospitals may be associated significantly with having more licensed doctors (≥161 vs. <161: odds ratio [OR], 1.30; 1.13-1.50; p < 0.01), having more frequency of registration appointments (≥3,356 vs. <3,356: OR, 1.77; 1.54-2.03; p < 0.01), having higher frequency of patient follow-ups (≥1,160 vs. <1,160: OR, 1.36; 1.15-1.61; p < 0.01), having laboratory test appointments (Yes vs. No: OR, 1.25; 1.06-1.48; p = 0.01), and having treatment appointments (Yes vs. No: OR, 1.27; 1.11-1.46; p < 0.01) in the past 3 months. Conclusions: The coverage of IMS is appreciable in China, but the IMS market is still greatly extended and improved. The provision of IMS depends primarily on the scales of the hospitals, including medical staff reserve and patient visiting capacity.

Green Extraction of Polyphenols from Elaeagnus angustifolia L. Using Natural Deep Eutectic Solvents and Evaluation of Bioactivity.

In the study, natural deep eutectic solvents (NADESs) were used as alternatives to traditional chemical solvents for the extraction of polyphenols from Elaeagnus angustifolia L. Nine NADESs were tested for the first time and compared with ethanol and water (traditional solvents) regarding the extraction of phenolic compounds from E. angustifolia L. These solvents were particularly effective at extracting polyphenols, whose low water solubility usually requires high amounts of organic solvents. The solvent based on choline chloride and malonic acid provided optimal results and was selected for further optimization. The effects of material-to-liquid ratio, ultrasound time, and ultrasound temperature on the extraction efficiency were studied through single-factor experiments. These parameters were optimized by Box-Behnken design using response surface methodology. The optimal conditions identified were 49.86 g/mL of material-to-liquid ratio, 31.10 min of ultrasound time, and 62.35 °C of ultrasound temperature, resulting in a high yield of 140.30 ± 0.19 mg/g. The results indicated that the NADES extraction technique provided a higher yield than the conventional extraction process. The antioxidant activity of the extract of polyphenols from E. angustifolia L. was determined, and UPLC-IMS-QTOF-MS was used to analyze the phenolic compounds in it. The results revealed that the scavenging ability of 1,1-diphenyl-2-picryl-hydrazil and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) extracted by NADES was higher than that of polyphenols extracted by water and ethanol. Furthermore, a total of 24 phenolic compounds were identified in the extract. To the best of our knowledge, this is the first study in which a green and efficient NADES extraction method has been used to extract bioactive polyphenols from E. angustifolia L., which could provide potential value in pharmaceuticals, cosmetics, and food additives.

High-Throughput Mining of Novel Compounds from Known Microbes: A Boost to Natural Product Screening.

Advanced techniques can accelerate the pace of natural product discovery from microbes, which has been lagging behind the drug discovery era. Therefore, the present review article discusses the various interdisciplinary and cutting-edge techniques to present a concrete strategy that enables the high-throughput screening of novel natural compounds (NCs) from known microbes. Recent bioinformatics methods revealed that the microbial genome contains a huge untapped reservoir of silent biosynthetic gene clusters (BGC). This article describes several methods to identify the microbial strains with hidden mines of silent BGCs. Moreover, antiSMASH 5.0 is a free, accurate, and highly reliable bioinformatics tool discussed in detail to identify silent BGCs in the microbial genome. Further, the latest microbial culture technique, HiTES (high-throughput elicitor screening), has been detailed for the expression of silent BGCs using 500-1000 different growth conditions at a time. Following the expression of silent BGCs, the latest mass spectrometry methods are highlighted to identify the NCs. The recently emerged LAESI-IMS (laser ablation electrospray ionization-imaging mass spectrometry) technique, which enables the rapid identification of novel NCs directly from microtiter plates, is presented in detail. Finally, various trending 'dereplication' strategies are emphasized to increase the effectiveness of NC screening.

Analysis of Volatile Aroma Components in Different Parts of Shiitake Mushroom (Lentinus edodes) Treated with Ultraviolet C Light-Emitting Diodes Based on Gas Chromatography-Ion Mobility Spectroscopy.

Further assessment of ultraviolet C light-emitting diode (UVC-LED) irradiation for influencing shiitake mushrooms' (Lentinus edodes) volatile and sensory properties is needed. In this study, a comparison of UVC-LED irradiation treatment on the flavor profiles in various parts of shiitake mushrooms was conducted using gas chromatography-ion mobility spectrometry (GC-IMS) and sensory analysis. Sixty-three volatile compounds were identified in shiitake mushrooms. The fresh shiitake mushrooms were characterized by the highest values of raw mushroom odors. After UVC-LED treatment, the content of C8 alcohols decreased, especially that of 1-octen-3-ol, while the content of aldehydes increased, especially the content of nonanal and decanal. The score of fatty and green odors was enhanced. For fresh samples, the mushroom odors decreased and the mushroom-like odors weakened more sharply when treated in ethanol suspension than when treated with direct irradiation. The fruit odors were enhanced using direct UVC-LED irradiation for fresh mushroom samples and the onion flavor decreased. As for shiitake mushroom powder in ethanol suspension treated with UVC-LED, the sweaty and almond odor scores decreased and the vitamin D2 content in mushroom caps and stems reached 668.79 µg/g (dw) and 399.45 µg/g (dw), respectively. The results obtained from this study demonstrate that UVC-LED treatment produced rich-flavored, quality mushroom products.

Exploring the Effect of Milk Fat on Fermented Milk Flavor Based on Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) and Multivariate Statistical Analysis.

Milk fat is a premium nutritional health product, yet there is a lack of high-fat dairy products for daily consumption in the current market. This study investigated the influence of different milk fat contents on the physicochemical and textural properties of fermented milk. The research revealed that an increase in milkfat content significantly improved the water-holding capacity, syneresis, color, hardness, springiness, gumminess, and chewiness of fermented milk, while showing minimal changes in pH and total titratable acidity. Response surface analysis indicated that fermented milk with 25% milk fat, 2.5% inoculum, a fermentation time of 16 h, and a fermentation temperature of 30 °C exhibited the highest overall acceptability. Using GC-IMS technology, 36 volatile compounds were identified, with an increase in milk fat content leading to elevated levels of ketone compounds, and 14 compounds were defined as key aroma compounds (ROAV > 1). Electronic nose distinguished samples with different milk fat contents. The results demonstrate that an increase in milk fat content enhances the physicochemical and flavor attributes of fermented milk. This work provides theoretical references for the production and development of high-fat fermented milk.

Comparative Analysis of Volatile Compounds in the Flower Buds of Three Panax Species Using Fast Gas Chromatography Electronic Nose, Headspace-Gas Chromatography-Ion Mobility Spectrometry, and Headspace Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry Coupled with Multivariate Statistical Analysis.

The flower buds of three Panax species (PGF: P. ginseng; PQF: P. quinquefolius; PNF: P. notoginseng) widely consumed as health tea are easily confused in market circulation. We aimed to develop a green, fast, and easy analysis strategy to distinguish PGF, PQF, and PNF. In this work, fast gas chromatography electronic nose (fast GC e-nose), headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), and headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) were utilized to comprehensively analyze the volatile organic components (VOCs) of three flowers. Meanwhile, a principal component analysis (PCA) and heatmap were applied to distinguish the VOCs identified in PGF, PQF, and PNF. A random forest (RF) analysis was used to screen key factors affecting the discrimination. As a result, 39, 68, and 78 VOCs were identified in three flowers using fast GC e-nose, HS-GC-IMS, and HS-SPME-GC-MS. Nine VOCs were selected as potential chemical markers based on a model of RF for distinguishing these three species. Conclusively, a complete VOC analysis strategy was created to provide a methodological reference for the rapid, simple, and environmentally friendly detection and identification of food products (tea, oil, honey, etc.) and herbs with flavor characteristics and to provide a basis for further specification of their quality and base sources.

Research on the brewing technology of Dangshen Huangjiu with low biogenic amines and high functional factors.

BACKGROUND: Biogenic amines (BA) are hazardous components in Huangjiu (HJ). To ensure the quality of Dangshen Huangjiu (DSHJ), an orthogonal experiment L9 (33) was proposed to optimize the process by the main brewing factors (pre-fermentation temperature, pre- and post-fermentation time) that may affect BA and functional factors in DSHJ. DSHJ was produced with low BA content and high functional factors. Gas chromatography-ion mobility spectrometry combined with a multivariate statistical method (GC-IMS-MSM) was used to analyze the volatile components in the brewing process of DSHJ. RESULTS: The optimum brewing process parameters of DSHJ were as follows: pre-fermentation temperature, 28 °C; pre-fermentation time, 9 days; post-fermentation time, 18 days. The average content of BA in DSHJ was 33.12 mg L-1, and the sensory score, total phenol content and DPPH free radical scavenging rate of DSHJ were significantly higher than those of HJ. A total of 14 esters, 7 acids, 7 alcohols, 1 ketone, 5 aldehydes and 1 pyrazine in DSHJ and HJ were identified by GC-IMS. There were no significant differences (P > 0.05) in DSHJ and HJ in the soaking rice and saccharification stage. 11 components, such as ethyl acetate, and 12 components, such as acetic acid, were the different components of HJ and DSHJ in pre-fermentation and post-fermentation stages, respectively. In the post-fermentation stage, the contents of 8 components in DSHJ such as ethyl acetate were higher than in HJ. CONCLUSION: The preparation process parameters of DSHJ optimized by orthogonal experiments can ensure that DSHJ has the advantages of low BA content, high total phenol content and good antioxidant activity. Sensory score and GC-IMS-MSM analysis found that DSHJ prepared using the optimal process had the characteristics of good taste and rich aroma. © 2024 Society of Chemical Industry.

Gas chromatography-ion mobility spectrometry (GC-IMS) technique and its recent applications in grain research.

Grains are the primary source of food for most people worldwide and constitute a major source of carbohydrates. Many novel technologies are being employed to ensure the safety and reliability of grain supply and production. Gas chromatography-ion mobility spectrometry (GC-IMS) can effectively separate and sensitively detect volatile organic compounds. It possesses advantages such as speed, convenience, high sensitivity, no pretreatment, and wide applicability. In recent years, many studies have shown that the application of GC-IMS technology for grain flavor analysis can play a crucial role in grains. This article elucidates the working principle of GC-IMS technology, reviews the application of GC-IMS in grains in the past 5 years. GC-IMS technology is mainly applied in four aspects in grains. In grain classification, it distinguishes varieties, quality, origin, production year, and processing methods based on the trace differences in volatile organic compounds, thereby fulfilling various grain classification requirements such as origin tracing, geographical indication product recognition, variety identification, production year identification, and detection of counterfeit and inferior grain samples. In optimizing the processing technology of grains and their products, it can improve food flavor, reduce undesirable flavors, and identify better processing parameters. In grain storage, it can determine the storage time, detect spoilage phenomena such as mold and discoloration during storage, eliminate pests affecting storage, and predict the vitality of seeds after storage. In aroma evaluation of grains and their processed products, it can assess the impact of new raw materials, new technologies, fermentation processes, and even oral processing on the quality of grain products. This article also summarizes the characteristics of GC-IMS technology, compiles typical grain flavor compounds, and provides prospects for the future application of GC-IMS. © 2024 Society of Chemical Industry.

Combining multivariate statistical analysis to characterize changes in amino acids and volatiles during growth of Lou onion pseudostems.

BACKGROUND: The main edible part of the Lou onion is the pseudostem, which is highly valued for its distinctive flavour. However, harvesting decisions for the pseudostem are often based on size and market price, with little consideration given to flavour. By clarifying the growth of flavour in pseudostems, farmers and consumers may benefit from evidence-based insights that help optimize harvesting time and maximize flavour quality. RESULTS: This study employed amino acid analysis and gas chromatography-ion migration spectroscopy (GC-IMS) to elucidate the compounds of the pseudostem across different growth phases, and 17 amino acids and 61 volatile substances. Subsequently, analysis revealed that 18 compounds, including arginine (Arg), aspartic acid (Asp), glutamic acid (Glu), valine (Val), (E)-2-nonenal, decanal, 2,4-nonadienal, 2-octenal, (Z)-4-decenal, 2,4-decadienal benzeneacetaldehyde, linalool, eugenol, (Z)-6-nonen-1-ol, methyl anthranilate, 2-acetylpyridine, 3-sec-butyl-2-methoxypyrazine, and 2,6-dichlorophenol, were the key compounds in determining the flavour characteristics of the pseudostems, as assessed by taste activity value and relative odour activity value calculations. In addition, correlation analysis, focusing on five amino acids and 38 volatile compounds with variable importance for predictive components scores of >1, identified anisaldehyde, eugenol, (Z)-6-nonen-1-ol, 2,4-decadienal, 3-sec-butyl-2-methoxypyrazine, Arg, Asp, and Val as the key differentiators and contributors to the pseudostems flavour profile. CONCLUSION: During the rapid growth of Lou onions just before the emergence of flower stems, the pseudostem exhibited the most prominent flavour, making this stage most suitable for harvesting compared to the regreening growth stage and the rapid growth period of the aerial bulbs. © 2024 Society of Chemical Industry.

Cooperative effects of three preservatives on physiological quality, endophytic bacterial community and volatile organic compounds of postharvest Codonopsis pilosula var. modesta roots.

BACKGROUND: Codonopsis pilosula var. modesta (CPVM) is a famous medicinal and edible plant of Campanulaceae. However, fresh CPVM roots (FCPVR) are prone to softening, browning and spoilage after concentrated harvesting in the main production area of Gansu Province, China in autumn, which poses great challenges to their large-scale storage and modern processing. In this study, effects of chitosan (CS), natamycin (NA) and modified atmosphere agent (MA) on the postharvest quality of FCPVR were first investigated. The roots after different treatments were stored at 4 °C and relative humidity of 75 ± 5% for 100 days. Their overall quality changes were evaluated from three perspectives: physiological quality, endophytic bacterial community and volatile organic compounds. RESULTS: The clustering heatmap and principal component analysis results indicated that CS (2 g kg-1), NA (0.5 g kg-1) and MA (5 g) had a synergistic effect on physiological quality. The roots in the CS + NA + MA group maintained better physiological state, effective components and antioxidant capacity throughout the storage process. On this basis, compared with room temperature storage, the relative abundance of the main spoilage bacterium Pseudomonas in the CS + NA + MA group roots decreased by 44% on the 100th day of storage. Furthermore, after CS + NA + MA composite treatment, the roots produced richer esters with fruit aroma during low-temperature storage. CONCLUSIONS: The CS + NA + MA composite treatment could maintain the physiological quality and flavor of FCPVR, inhibit spoilage by microbial contamination and maintain the optimal quality during low-temperature storage for up to 100 days. © 2024 Society of Chemical Industry.

Histochemistry and Cell Biology-a glance into the past and a look ahead.

At the occasion of the 65th anniversary of Histochemistry and Cell Biology, we browse through its first ten years of publication and highlight a selection of papers from the early days of enzyme, protein, and carbohydrate histochemistry. In addition, we narrate recent progress to identify, quantify, and precisely determine the tissue localization of proteins and lipids, and small molecules by the combination of spectroscopic techniques and histology.