Identifying Putative Biomarkers of Foodborne Pathogens Using a Metabolomic Approach.

Metabolomics is the study of low molecular weight biochemical molecules (typically <1500 Da) in a defined biological organism or system. In case of food systems, the term "food metabolomics" is often used. Food metabolomics has been widely explored and applied in various fields including food analysis, food intake, food traceability, and food safety. Food safety applications focusing on the identification of pathogen-specific biomarkers have been promising. This chapter describes a nontargeted metabolite profiling workflow using gas chromatography coupled with mass spectrometry (GC-MS) for characterizing three globally important foodborne pathogens, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica, from selective enrichment liquid culture media. The workflow involves a detailed description of food spiking experiments followed by procedures for the extraction of polar metabolites from media, the analysis of the extracts using GC-MS, and finally chemometric data analysis using univariate and multivariate statistical tools to identify potential pathogen-specific biomarkers.

Phytochemical Profiling and Bioactive Properties of Essential Oils from Endemic Palestinian Satureja thymbrifolia.

Despite several studies on the Satureja L. genus, the chemical composition and biological activities of the traditional medicinal plant Satureja thymbrifolia (White Thyme), a Palestinian endemic species, are still unknown. It grows in arid regions and is used by Bedouins as a traditional medicinal herb. This study aimed to investigate S. thymbrifolia essential oils (EOs), mainly from its phytochemical pattern and biological properties. The GC-MS study identified p-cymene (48.53%) and thymol (23.27%) as the leading EOs components. Compared to Trolox, the EOs showed potential anti-DPPH free radical activity and had broad-spectrum antimicrobial potentials, with MIC values ranging from 0.13 ± 0.05 to 25 ± 0.00 µL/mL. They were most effective against Candida albicans species. The S. thymbrifolia EOs most effectively eliminated cancer cells when tested against CaCo-2 and HeLa cell lines (IC50 values of 192.15 ± 2.47 and 194.80 ± 1.87 µg/mL, respectively). The present investigation is the first documented study of S. thymbrifolia EOs' phytochemical composition and bioactivities. The results revealed that S. thymbrifolia EOs have potential antioxidant, antimicrobial, and cytotoxic effects. These outcomes emphasized S. thymbrifolia EO's potential dietary, pharmacological, and cosmetic applications.

Comparison of the presence of high production volume chemicals in farmed and wild fish highly consumed in catalonia and their risk assessment.

The decline in fish populations and the depletion of marine resources have sparked concerns about sustainable fish production, driving the innovation of new aquaculture methods. While some argue that wild fish are healthier than farmed fish due to less exposure to contaminants and pathogens, wild fish can accumulate contaminants from more contaminated water sources. The slower growth of wild fish and their longer exposure to the environment may contribute to higher pollutant levels in fish tissues. In this study, we focus on 25 contaminants considered as high production volume chemicals (HPVCs), such as organophosphate esters (OPEs), benzothiazoles (BTs), benzosulfonamides (BSAs) and phthalates (PAEs). The compounds were extracted from the edible part of the fish using the QuEChERS method and analysed by gas chromatography-tandem mass spectrometry. A total of 74 samples were analysed from three of the most commonly consumed species in Catalonia, Spain (turbot, sea bass and sea bream). Two samples of each species were collected each month, one form farmed and one from wild origin. In general, the compounds were found in all the samples in a wide concentrations range, although no significant differences were observed between the mean concentration of wild and farmed samples. Although similar mean concentrations for the OPEs, BTs and BSAs were found between farmed and wild origin samples, PAEs were more frequently detected in farmed samples. Di-n-octyl phthalate and diethyl phthalate showed the highest concentrations in all fish samples, with values up to 19505 and 17605 ng g-1 (d.w.), in sea bass and sea bream, respectively. Di-(2-ethylexyl)-adipate proved to be the most relevant carcinogenic compound, with no associated health risk. Despite the detection of the studied HPVCs, no health risk was associated with the consumption of these three fish species.

Development of GC-MS coupled to GC-FID method for the quantification of cannabis terpenes and terpenoids: Application to the analysis of five commercial varieties of medicinal cannabis.

Cannabis terpenes and terpenoids are among the major classes of pharmacologically active secondary metabolites of therapeutic interest. Indeed, these hydrocarbon molecules, responsible for the characteristic aroma of cannabis flowers, are thought to be involved in a synergistic effect known as the "entourage effect", together with cannabinoids. Numerous analytical studies have been carried out to characterize the terpene and terpenoid contents of some cannabis varieties, but they have not proposed any real quantification or have described a limited number of analytical standards or average response factors, which may have led to over- or underestimation of the real content of the cannabis flowers. Real and reliable quantification is necessary to justify the entourage effect. Here, we report a rigorous and precise GC-FID and GC-MS method for the identification and quantification of cannabis terpenes and terpenoids. This method is distinguished by the use of a high number of analytical standards, the determination of retention indices for all compounds studied, an exhaustive comparison of databases and scientific literature, the use of relevant response factors, and internal calibration for reliable results. It was applied to the study of terpenic compounds in five commercial varieties of medicinal cannabis produced by Bedrocan International: a CBD-rich (Bedrolite®), a THC/CBD balanced (Bediol®), and three THC-dominant (Bedrocan®, Bedica® and Bedrobinol®). Two extraction solvents are described (ethanol and hexane) to compare their selectivity towards target molecules, and to describe as exhaustively as possible the terpenic profile of the five pharmaceutical-grade varieties. Twenty-three standards were used for accurate dosages. This work highlights that the choice of solvent and the analysis method reliability are critical for the study of these terpenic compounds, regarding their contribution to the entourage effect.

Analysis of glycerol bound ω-oxo-fatty acids as ω-dioxane-FAME-derivatives.

ω-oxo-fatty acids, also known as aldehydic fatty acids, are major products of fatty acid oxidation and pose potential health risks. When bound to glycerol, ω-oxo-fatty acids (core aldehydes) can be ingested with food. Challenges in GC-MS quantification include the absence of an appropriate internal standard. Additionally, substantial analyte losses during sample preparation, caused by the high volatility of short-chain compounds, alter their pattern based on molecular weight. In this study, among various tested derivatization methods, the formation of ω-dioxane derivatives demonstrated improved recovery rates after three evaporation cycles. For methyl 7-oxo-heptanoate, recovery increased from 43 % to 88 %, while recovery rates for different chain lengths and a novel synthesized internal standard improved from a range of 43 %-76 % to 87 %-92 %. Additionally, ω-dioxane derivatives displayed favorable GC-MS behavior, enabling clear identification and increased sensitivity. Finally, ω-oxo-fatty acids were quantified as their ω-dioxane-derivatives in thermally treated sunflower and rapeseed oil.

[Influence of different processing methods on volatile components of Atractylodis Rhizoma based on HS-GC-MS technology].

The volatile components of Atractylodis Rhizoma have obvious pharmacological effects and are considered to be the main dry components of Atractylodis Rhizoma. The differences of different processed products of Atractylodis Rhizoma were analyzed from the perspective of volatile oil changes to explain the reasons for dryness reduction and efficacy increase of Atractylodis Rhizoma after processing. HS-GC-MS technology was used to obtain the volatile components of raw Atractylodis Rhizoma, bran-fried Atractylodis Rhizoma, roasted Atractylodis Rhizoma, and rice-water processed Atractylodis Rhizoma under four different processes, and then SIMCA software was used to analyze the volatile oil components of Atractylodis Rhizoma and its different processed products. A total of 87 volatile components were identified in the HS-GC-MS results. A total of 76 volatile components were identified in raw products; 79 volatile components were identified in bran-fried Atractylodis Rhizoma; 70 volatile components were identified in Zhangbang rice-water processed Atractylodis Rhizoma; 81 volatile components were identified in roasted Atractylodis Rhizoma; 78 volatile components were identified in Hunan rice-water processed Atractylodis Rhizoma; 73 volatile components were identified in Jilin rice-water processed Atractylodis Rhizoma, and 77 volatile components were identified in Shanghai rice-water processed Atractylodis Rhizoma. Through multivariate statistical analysis, it was found that there were significant differences between the processed products of Atractylodis Rhizoma. Then, a total of 28 significant differential components between the symbiotic products and the six processed products were established by the OPLS-DA model. Among them, 11 volatile components that generally increased significantly after processing were α-pinene, phellandrene,(1S)-(+)-3-carene, o-isopropyltoluene, D-limonene, α-ocimene, α-isoterpinene, silphiperfol-5-ene,silphinene, γ-alkenyl, and germacrene B, which may be related to their synergistic effect. Five volatile components that generally decreased significantly after processing were ß-elemene, 1-methyl-4-(6-methylhept-5-en-2-yl) cyclohexa-1, 3-diene, ß-selinene,ß-sesquiphellandrene, and atractylon, which may be related to their dryness.

Analysis of PFAS and further VOC from fluoropolymer-coated cookware by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS).

Per- and polyfluoroalkyl substances (PFAS) are used in the production of PTFE based coatings for cookware. In this study, emission of PFAS and further volatile organic compounds (VOC) from kitchenware articles were investigated. First, method development for thermal extraction of baking trays, frying pans and baking mats at 250 °C was done by testing three different extraction devices. A thermal desorption oven showed the best blank and highest recoveries of PFAS analytes (70-101% for 12 perfluorocarboxylic acids (PFCAs), 2 fluorotelomer alcohls (FTOHs), 3 per- and polyfluoroether carboxylic acids (PFECAs), 1 polyfluoroether (PFE)). Second, 18 cookware samples, a PTFE micro powder and 2 lab made coating strips have been investigated. No PFAS were detected in 12 samples (limits of detection: 1-13 ng/dm2). PFCAs (C5-C23) were detected in a baking tray in amounts up to 34 ng/dm2. A baking mat contained 3 ng/dm2 PFOA. FTOHs were not detected in the samples. A PFECA (bC7O2) and its hydride (bC6O2H PFE) were detected in one coating intended for use in frying pans. The hydrides of the PFECA mixture, b(C3O1)nC3 PFECA (Krytox 157FSH), were detected in five baking trays. The PFAS target analytes were not detectable in the five investigated frying pans. Analysing further VOC in the emissions of coatings, 175 compounds could be identified, including alkanes, alkenes, aromatic substances, esters, aldehydes, ketones, ethers, alcohols, carboxylic acids, siloxanes and sulphur, nitrogen, as well as chlorine containing compounds (< 10 µg/dm2). The identified substances cannot be connected to the basic coating polymer of the kitchenware articles, which were PTFE and PES. All samples have undergone a threefold thermal extraction. No substances could be detected in the second and third consecutive extraction, which means that a removal and no new formation of the investigated PFAS as well as the further VOC at 250 °C has occurred.

Anti-arthritic studies of ethnomedicine Gaultheria trichophylla Royle extract and salicylate-rich fraction using complete Freud's adjuvant-induced rats: molecular docking and network pharmacology analysis.

Gaultheria trichophylla Royle is a traditional treatment for inflammatory conditions including arthritis. The objective was to evaluate the anti-arthritic activity of the extracts and salicylate-rich fractions through adjuvant-induced arthritis, histopathological analysis, radiological imaging, hematological, biochemical parameters along with using bioinformatic tools. In vivo anti-arthritic efficacy of the extract and SRF (at 100, 200, 300, and 150 mg/kg doses) was assessed using healthy albino rats. Molecular docking of identified compounds along with network pharmacology analysis helped to determine the route of action of drug. Both the extract and SRF showed dose-dependent anti-arthritic activity by decreasing the joint diameter, increase in pain threshold and body weight compared with negative control group. Along with SRF (150 mg/kg), EEGT (300 and 200 mg/kg) shows significant (P < 0.01) anti-arthritic activity by lowering levels of WBC, platelets, serum C-reactive protein (CRP), and rheumatoid factor (RF) and raising levels of RBC and Hb. The modified biochemical measures (AST, ALT, ALP, and total protein level) further supported the anti-arthritic action. Histopathology and radiology study showed that EEGT (300 and 200 mg/kg), SRF (150 mg/kg) and diclofenac (10 mg/kg) inhibited joint destruction. GCMS analysis showed the presence of methyl salicylate, sitosterol, calcifediol, and ergosta-5,22-dien-3-ol, acetate as important bioactive constituents. Moreover, as the significant node in the pharmacology network and docking against TNF-α, a classical therapeutic target in RA showed potential of G. trichophylla in treatment of RA. The results showed that G. trichophylla have effectively reduced the inflammation of the joints.

Spectroscopic and chromatographic studies of chemical constituents of wild A.pindrow royle: facile foliar fuel for the synthesis of nanomaterials.

The current work is the first ever report on the functionalization of CoO nanoparticles (NPs) using the bio active constituents of Abies pindrow Royle (A.pindrow) leaves. An efficient phytochemical extraction method was determined by comparing different extraction strategies for extracting the biologically active compounds of A.pindrow leaves. The phytocompounds were noticed via chromatographic techniques; High-performance liquid chromatography (HPLC) as well as the Gas chromatography-mass spectroscopy (GC-MS) followed by spectroscopic analysis that is the Fourier transform infrared spectroscopy (FTIR) along with Ultraviolet-visible spectroscopy (UV-Vis). The reducing properties of the phytochemicals were investigated by efficiently synthesizing metal oxides nanoparticles (CoO NPs) by treating aqueous plant extract with Co(NO3). 6H2O aqueous complex. The newly synthesized NPs were characterized via X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and field emission-scanning electron microscopy (FE-SEM). Finally, the GCMS, FTIR and UV-Vis identified the A.pindrow leaves biocomponents as capping and reducing mediator of the synthesized CoO nanoparticles. FTIR confirmed the prepartion of CoO NPs as well as the capping and stabilizing agents of A.Pindrow at 2378.31 cm-1, 1370.11 cm-1, 1260.57 cm-1, 937.4 cm-1 and 607.24 cm-1 having carboxylic acid, alcohols, aromatics, alkenes, aromatic amines, esters as well as ethers functional groups, flavonols and flavonoids phytochemicals. Moreover GCMS analysis revealed the dominating constituents of A.pindrow leaf extracts are carbohydrates, terpenoids, alkanoids, flavonoids as well as phenols. Furthermore, the antibacterial and bioactive agent, tannis was also observed in aqueous extract. These phytochemicals noticed in this current work, has antioxidant potential, that is why they have shown biomedical applications. The present manipulation, further articulated that, maximum phytochemicals extraction of A. pindrow leaves was illustrated in the aqueous extract as compared to ethyl acetate and ethanol.

'Bhim Kol (Musa balbisiana)' Wine: Chemical Profiling and Antidiabetic Properties with MD Simulation Insights.

Musa balbisiana (Bhim Kol), an exotic fruit that offers numerous benefits can be fermented to obtain a unique indigenous wine. This study explores the fermentation of Musa balbisiana (Bhim Kol) fruit to produce a unique indigenous wine using strain of Saccharomyces cerevisiae and sugar over a 21-day period. Chemical profiling via GC-MS analysis revealed the presence of major volatile compounds such as butan-1-ol, propanoic acid, 2-phenylethanol, oxolane-2,5-dione etc. The wine exhibited in vitro α-glucosidase inhibition activity with an IC50 value of 8.56 ± 0.14 µg/mL and antioxidant properties (DPPH· scavenging activity (AAR) of 1.29 ± 0.18 mM TRE). Molecular docking and simulation studies indicated potential binding of volatile compounds like 4-Hydroxy-3-methoxybenzoic acid, 2-phenylethanol, butan-1-ol and butane-2,3-diol with α-glucosidase enzyme. The study suggests the medicinal potential of the wine and its suitability for commercial production in the winery industry. Further studies are warranted to explore its full medicinal benefits.

Chemical Characterization, Evaluation of Acute Oral Toxicity, and Anti-Diabetic Activity of Aloe sabaea Flowers Extract on Alloxan-Induced Diabetic Rats.

The study aimed to conduct chemical profiling, acute in-vivo toxicity evaluation, and the potential anti-diabetic effect of standardized Aloe sabaea flowers ethanolic extracts (ASFEE) on alloxan-induced diabetic rats. The chemical composition was analyzed using GC-MS and TLC techniques. The oral acute toxicity study was performed according to the WHO 2000 and the OECD 420 guidelines. Furthermore, anti-diabetic activity was investigated using two doses of ASFEE (0.2 and 0.5 g/kg/day BW, p.o.) compared with glibenclamide (5 mg/kg/day, p.o.). A molecular docking investigation of the identified components with the PTPN9 enzyme was performed to figure out the proposed anti-diabetic mechanism. GC-MS analysis displayed the existence of 18 compounds; most of the compounds were fatty acids and their esters, and phytosterols. Total phenolic and flavonoid contents were 42.00±1.26 mg GAE/g DW and 22.21±1.55 mg QE/g DW, respectively. The results of the in-vivo toxicity study revealed the absence of noticeable signs of toxicity or mortality at various doses establishing the safety of the tested extract. The estimated LD50 value was higher than 10 g/kg. Antidiabetic action exhibited a noticeable decline in fasting blood glucose (FBG) levels comparable to glibenclamide with no inducing intense hypoglycemia and considerable excess weight.

Bioactive constituents and acute toxicity of Blighia sapida capsule extracts using wistar rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Blighia sapida, commonly known as Ackee, is a plant native to West Africa, with great cultural and therapeutic value, particularly in Western Nigeria. Traditionally, Blighia sapida capsule is used in western Nigeria to treat ecthyma in sheep and goats by heating it in hot ash. This process causes the capsule to release a liquid, which is then directly applied to the entire affected area of the skin. However, there is limited information available on its phyto-constituents and medicinal effects. AIM OF THE STUDY: This work examined the bioactive constituents, acute toxicity, and sub-acute toxicity of aqueous and ethanolic extracts of Blighia sapida capsule. MATERIALS AND METHODS: Extraction of phytochemical constituents was carried out with distilled water and ethanol and was concentrated at 40 °C. The phytochemical constituents were determined using a variant 3800/4000 gas chromatography-mass spectrometry (GC-MS) machine. Lorke's method was employed to determine the acute toxicity of the aqueous and ethanolic extracts of Blighia sapida capsule. RESULTS: The GC-MS analysis revealed 15 bioactive compounds in both extracts, with kaempferol being the most abundant. Notable pharmacologically active compounds included pyrrolidin-2-ylmethanol, rutin, quinoline, apigenin, and naringenin. The study observed distinctive differences in aqueous and ethanolic extracts compound weights and peak areas. Acute toxicity study depicts that the lethal dose of aqueous and ethanolic extracts of Blighia sapida capsule is above 5000 mg/kg as no mortality was recorded in the oral administration of 10, 100, 1000, 1600, 2900, and 5000 mg/kg of aqueous and ethanolic extracts. Sub-acute toxicity results indicated no significant adverse effects on kidney and liver function, although some variations in biochemical parameters were observed. Histological analysis showed normal renal and hepatic architecture in treated animals. CONCLUSION: This study demonstrated that aqueous and ethanolic extracts of Blighia sapida capsule exhibited no acute toxicity and minimal sub-acute toxicity, suggesting they are safe for consumption at the tested doses.

Wild Pepper (Piper laetispicum) Fruit Quality Traits at Different Developmental Stages.

High-quality Piper laetispicum (Piper laetispicum C. DC) is the key to the development of foods, natural medicines, and cosmetics. Its crude fat, ash, piperine, protein, and aroma compounds were determined in this experiment. Principal component (PCA) and hierarchical cluster analyses (HCA) were used to evaluate the aroma compounds at different developmental stages. The main aroma compounds identified using steam distillation combined with GC-MS were sabinene (34.83-76.14%), α-copaene (5.11-19.51%), linalool (2.42-15.70%), trans-caryophyllene (2.37-6.57%), α-pinene (1.51-4.31%), and germacrene D (1.30-4.10%). The aroma metabolites at different developmental stages were analysed using non-targeted metabolomes, and linalool was found to be the most abundant. Based on the experimental results, there were more nutrient compounds in young Piper laetispicum than in the last three developmental stages. The aromatic metabolites contributed the most to PC1. There were also more different metabolites of aroma between the young and expanding stages. Therefore, regarding quality, young fruits have great potential.

The Effect of the Extraction Conditions on the Antioxidant Activity and Bioactive Compounds Content in Ethanolic Extracts of Scutellaria baicalensis Root.

Ethanolic extracts of Baikal skullcap (Scutellaria baicalensis) root were obtained using various techniques, such as maceration, maceration with shaking, ultrasound-assisted extraction, reflux extraction, and Soxhlet extraction. The influence of the type and time of isolation technique on the extraction process was studied, and the quality of the obtained extracts was determined by spectrophotometric and chromatographic methods to find the optimal extraction conditions. Radical scavenging activity of the extracts was analyzed using DPPH assay, while total phenolic content (TPC) was analyzed by the method with the Folin-Ciocalteu reagent. Application of gas chromatography with mass selective detector (GC-MS) enabled the identification of some bioactive substances and a comparison of the composition of the particular extracts. The Baikal skullcap root extracts characterized by both the highest antioxidant activity and content of phenolic compounds were obtained in 2 h of reflux and Soxhlet extraction. The main biologically active compounds identified in extracts by the GC-MS method were wogonin and oroxylin A, known for their broad spectrum of biological effects, including antioxidant, anti-inflammatory, antiviral, anticancer, and others.

The Cytotoxic Activity and Metabolic Profiling of Hyptis rhomboidea Mart. et Gal.

Many naturally occurring chemical metabolites with significant cytotoxic activities have been isolated from medicinal plants and have become the leading hotspot of anti-cancer research in recent years. Hyptis rhomboidea Mart. et Gal is used as a folk medicine in South China to treat or assist in the treatment of liver disease, ulcers, and edema. But its chemical constituents have not been fully investigated yet. This study aimed to assess the cytotoxicity of H. rhomboidea, which was chemically characterized by chromatography-mass spectrometry methods. The results showed that the 95% ethanol extract of H. rhomboidea has marked inhibitory effects on five human cancer cell lines (HL-60, A549, SMMC-7721, MDA-MB-231, and SW480), with IC50 values ranging from 15.8 to 40.0 µg/mL. A total of 64 compounds were identified by ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and gas chromatograph-mass spectroscopy (GC-MS) analysis of H. rhomboidea crude extract. Among them, kaempferol, quercetin, rosmarinic acid, squalene, and campesterol were found to be abundant and might be the major metabolites involved to its bioactivity. The cytotoxic characterization and metabolite profiling of H. rhomboidea displayed in this research provides scientific evidence to support its use as medicinal properties.

The Content of Volatile Organic Compounds in Calypogeia suecica (Calypogeiaceae, Marchantiophyta) Confirms Genetic Differentiation of This Liverwort Species into Two Groups.

Calypogeia is a genus of liverworts in the family Calypogeiaceae. The subject of this study was Calypogeia suecica. Samples of the liverwort Calypogeia suecica were collected from various places in southern Poland. A total of 25 samples were collected in 2021, and 25 samples were collected in 2022. Volatile organic compounds (VOCs) from liverworts were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 107 compounds were detected, of which 38 compounds were identified. The identified compounds were dominated by compounds from the sesquiterpene group (up to 34.77%) and sesquiterpenoids (up to 48.24%). The tested samples of Calypogeia suecica also contained compounds belonging the aromatic classification (up to 5.46%), aliphatic hydrocarbons (up to 1.66%), and small amounts of monoterpenes (up to 0.17%) and monoterpenoids (up to 0.30%). Due to the observed differences in the composition of VOCs, the tested plant material was divided into two groups, in accordance with genetic diversity.

The Role of Indigenous Yeasts in Shaping the Chemical and Sensory Profiles of Wine: Effects of Different Strains and Varieties.

The microbial terroir is an indispensable part of the terroir panorama, and can improve wine quality with special characteristics. In this study, eight autochthonous yeasts (Saccharomyces cerevisiae), selected in Huailai country, China, were trailed in small-scale and pilot fermentations for both white (Riesling and Sémillon) and red (Cabernet Sauvignon and Syrah) wines and evaluated by GC-MS analysis and the rate-all-that-apply (RATA) method. Compared to commercial yeast strains, the indigenous yeasts were able to produce higher concentrations of ethyl esters and fatty acid ethyl esters, and higher alcohol, resulting in higher odor activity values of fruity, floral attributes. Marked varietal effects were observed in the pilot fermentation, but yeast strains exerted a noticeable impact in modulating wine aroma and sensory profile. Overall, indigenous yeast could produce more preferred aroma compounds and sensory characteristics for both white and red wines, demonstrating the potential for improving wine quality and regional characteristics.

The optimization and validation of a gas chromatography-mass spectrometry method to analyze the concentration of acetate, propionate and butyrate in human plasma or serum.

Fermentation-derived short-chain fatty acids (SCFA)4 are potential mediators of the health benefits associated with dietary fiber intake. SCFA affect physiological processes locally in the gut and on distant organs via the systemic circulation. Since SCFA are used as energy source for colonocytes and substrate for the liver metabolism, their concentrations in the systemic circulation are low. Therefore, quantification of systemic SCFA requires sensitive analytical techniques. This article covers the optimization and validation of a gas chromatography-mass spectrometry method to measure systemic SCFA concentrations following derivatization with 2,4-difluoroaniline (DFA)5 and extraction in ethyl acetate. Sample preparation was optimized by varying the amount of DFA, coupling agent 1,3-dicyclohexylcarbodiimide, ethyl acetate and sodium bicarbonate, which is used to quench derivatization. In addition, evaporation of the samples using a vacuum concentrator resulted in less contamination, notably of acetate, compared to drying with N2 gas. The method showed excellent linearity with coefficient of variation (R2) > 0.99 and a good precision (relative standard deviation < 20 %) and accuracy. Finally, systemic concentrations of SCFA in human plasma samples could successfully be determined.

Comparison and identification of aroma components in 21 kinds of frankincense with variety and region based on the odor intensity characteristic spectrum constructed by HS-SPME-GC-MS combined with E-nose.

Frankincense is an important seasoning and spice known for its distinctive and intricate flavor profile. Considering the considerable variation in the aromatic quality of frankincense due to geographical origin, species diversity and cultivation conditions, frankincense from major global origins was characterized holistically for the first time. The electronic nose (E-nose) with headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) and sensory evaluation were implemented to characterize the aroma components of 21 commercial varieties of frankincense from around the world. The results showed that a total of 149 volatile organic compounds (VOCs) of 10 categories were identified in frankincense, among which the numbers of alcohols, terpenes and esters compounds accounted for 22.15 %, 18.79 % and 15.44 % of the total VOCs of frankincense, respectively. The PLS-DA model effectively distinguished frankincense from Oman/Somalia and other origins. Furthermore, the study identified two differential VOCs with VIP > 1 in three Asian countries and five in six African countries. The total VOCs content and sensory characteristic score of "Lemon/Citrus" in Oman frankincense is significantly higher than other regions. The OAV results showed that 61 substances (e.g., Diacety, alpha-Pinene, Camphene, Myrcene) as key aroma compounds and OICS model indicated that p-Cymenol was found to contribute significantly to the citrus aroma in frankincense. This study identified the fundamental components of frankincense flavor and revealed different flavor descriptors of frankincense, which are crucial for reconstructing frankincense flavor and improving flavor quality.

Comprehensive determination of fatty acids in real samples without derivatization by DMU-SPME-GC methods.

The comprehensive determination of fatty acids without derivatization, including short-chain fatty acids (SCFAs), medium-chain fatty acids (MCFAs) and long-chain fatty acids (LCFAs), is a big challenge but powerful for lipidomics in biology, food, and environment. Herein, the dual mode unity solid-phase microextraction (DMU-SPME) combined with gas chromatography-flame ionization detector (GC-FID) or mass spectrometry (MS) was proposed as a powerful method for the determination of comprehensive free fatty acids in real samples. Under the optimized DMU-SPME conditions, the proposed method has good linearity (R2 ≥ 0.994) and low limits of determination (0.01-0.14 mg/L). In the stability analysis, the intra-day relative standard deviation was 1.39-12.43 %, and the inter-day relative standard deviation was 2.84-10.79 %. The recoveries of selected 10 fatty acids in real samples ranged from 90.18 % to 110.75 %, indicating that the method has good accuracy. Fatty acids ranging from C2 to C22 were detected in real samples by the untargeted determination method of DMU-SPME combined with gas chromatography-mass spectrometry (GC-MS). The DMU-SPME method proposed in this study can be used for lipid metabolism analysis and free fatty acid determination in the fields of biology, food, and environment.