Identifying potential breath biomarkers for early diagnosis of papillary thyroid cancer based on solid-phase microextraction gas chromatography-high resolution mass spectrometry with metabolomics.

INTRODUCTION: Thyroid cancer incidence rate has increased substantially worldwide in recent years. Fine needle aspiration biopsy (FNAB) is currently the golden standard of thyroid cancer diagnosis, which however, is invasive and costly. In contrast, breath analysis is a non-invasive, safe and simple sampling method combined with a promising metabolomics approach, which is suitable for early cancer diagnosis in high volume population. OBJECTIVES: This study aims to achieve a more comprehensive and definitive exhaled breath metabolism profile in papillary thyroid cancer patients (PTCs). METHODS: We studied both end-tidal and mixed expiratory breath, solid-phase microextraction gas chromatography coupled with high resolution mass spectrometry (SPME-GC-HRMS) was used to analyze the breath samples. Multivariate combined univariate analysis was applied to identify potential breath biomarkers. RESULTS: The biomarkers identified in end-tidal and mixed expiratory breath mainly included alkanes, olefins, enols, enones, esters, aromatic compounds, and fluorine and chlorine containing organic compounds. The area under the curve (AUC) values of combined biomarkers were 0.974 (sensitivity: 96.1%, specificity: 90.2%) and 0.909 (sensitivity: 98.0%, specificity: 74.5%), respectively, for the end-tidal and mixed expiratory breath, indicating of reliability of the sampling and analysis method CONCLUSION: This work not only successfully established a standard metabolomic approach for early diagnosis of PTC, but also revealed the necessity of using both the two breath types for comprehensive analysis of the biomarkers.

Toxicity Assessment of Environmental Liquid Crystal Monomers: A Bacteriological Investigation on Escherichia coli and Staphylococcus epidermidis.

The widespread existence of liquid crystal monomers (LCMs) in various environmental matrices has been demonstrated, yet studies on the toxicological effects of LCMs are considerably scarce and are urgently needed to be conducted to assess the adverse impacts on ecology and human health. Here, we conducted a bacteriological study on two representative human commensal bacteria, Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis), to investigate the effect of LCMs at human-relevant dosage and maximum environmental concentration on growth, metabolome, enzymatic activity, and mRNA expression. Microbial growth results exhibited that the highest inhibition ratio of LCMs on S. epidermidis reached 33.6% in our set concentration range, while the corresponding data on E. coli was only 14.3%. Additionally, LCMs showed more dose-dependent toxicity to S. epidermidis rather than E. coli. A novel in vivo solid-phase microextraction (SPME) fiber was applied to capture the in vivo metabolites of microorganisms. In vivo metabolomic analyses revealed that dysregulated fatty acid metabolism-related products of both bacteria accounted for >50% of the total number of differential substances, and the results also showed the species-specific and concentration-dependent metabolic dysregulation in LCM-exposed bacteria. The determination of enzymatic activity and mRNA relative expression levels related to oxidative stress confirmed our speculation that the adverse effects were related to the oxidative metabolism of fatty acids. This study complements the gaps in toxicity data for LCMs against bacteria and provides a new and important insight regarding metabolic dysregulation induced by environmental LCMs in human commensal bacteria.

Solid-phase microextraction coupled to comprehensive multidimensional gas chromatography for food analysis.

Solid-phase microextraction and comprehensive multidimensional gas chromatography represent two milestone innovations that occurred in the field of separation science in the 1990s. They have a common root in their introduction and have found a perfect coupling in their evolution and applications. This review will focus on food analysis, where the paradigm has changed significantly over time, moving from a targeted analysis, focusing on a limited number of analytes at the time, to a more holistic approach for assessing quality in a larger sense. Indeed, not only some major markers or contaminants are considered, but a large variety of compounds and their possible interaction, giving rise to the field of foodomics. In order to obtain such detailed information and to answer more sophisticated questions related to food quality and authenticity, the use of SPME-GC × GC-MS has become essential for the comprehensive analysis of volatile and semi-volatile analytes. This article provides a critical review of the various applications of SPME-GC × GC in food analysis, emphasizing the crucial role this coupling plays in this field. Additionally, this review dwells on the importance of appropriate data treatment to fully harness the results obtained to draw accurate and meaningful conclusions.

The influence of drying and storage conditions on the volatilome and cannabinoid content of Cannabis sativa L. inflorescences.

The increasing interest in hemp and cannabis poses new questions about the influence of drying and storage conditions on the overall aroma and cannabinoids profile of these products. Cannabis inflorescences are subjected to drying shortly after harvest and then to storage in different containers. These steps may cause a process of rapid deterioration with consequent changes in precious secondary metabolite content, negatively impacting on the product quality and potency. In this context, in this work, the investigation of the effects of freeze vs tray drying and three storage conditions on the preservation of cannabis compounds has been performed. A multi-trait approach, combining both solid-phase microextraction (SPME) two-dimensional gas chromatography coupled to mass spectrometry (SPME-GC × GC-MS) and high-performance liquid chromatography (HPLC), is presented for the first time. This approach has permitted to obtain the detailed characterisation of the whole cannabis matrix in terms of volatile compounds and cannabinoids. Moreover, multivariate statistical analyses were performed on the obtained data, helping to show that freeze drying conditions is useful to preserve cannabinoid content, preventing decarboxylation of acid cannabinoids, but leads to a loss of volatile compounds which are responsible for the cannabis aroma. Furthermore, among storage conditions, storage in glass bottle seems more beneficial for the retention of the initial VOC profile compared to open to air dry tray and closed high-density polyethylene box. However, the glass bottle storage condition causes formation of neutral cannabinoids at the expenses of the highly priced acid forms. This work will contribute to help define optimal storage conditions useful to produce highly valuable and high-quality products.

Volatolomics to Decrypt the Monophagous Nature of a Rice Pest, Scirpophaga Incertulas (Walker).

Scirpophaga incertulas Walker (Lepidoptera: Crambidae, yellow stem borer, YSB) is a monophagous insect pest that causes significant yield loss in rice (Oryza staiva L.). Semiochemical based pest management is being sought as an alternate to chemical pesticides to reduce pesticide footprints. We hypothesized differential release of volatiles from host rice and two companion non-host weeds, Echinochloa colona and Echinochloa crus-galli could be responsible for oviposition and biology of YSB and these chemicals could be used for YSB management. Number of eggs laid, and number of larvae hatched were significantly higher in rice plant as compared to weeds. YSB could only form dead hearts in rice plants. YSB significantly preferred host-plant volatiles compared to the non-host plants both in choice and no-choice tests in an Y-tube olfactometer. 2-Hexenal, hexanal, 2,4-hexadienal, benzaldehyde, nonanal, methyl salicylate and decanal were found in the leaf volatolomes of both the host and non-host plants in HS-SPME-GC-MS (Headspace-Solid phase micro extraction-Gas chromatography-Mass spectrometer). Pentene-3-one, 2-pentyl furan, 2,4-heptadienal, 2-octenal, 2-octenol and menthol were present only in the non-host plants. Fourteen rice unique compounds were also detected. The built-in PCA (Principal Component Analysis) and PLS-DA (Partial least squares-discriminant analysis) analysis in the MS-DIAL tool showed that the volatiles emitted from TN1 formed a cluster distinct from Echinochloa spp. and 2-octenal was identified as a unique compound. Olfactometer bioassays using synthetic compounds showed that rice unique compounds, like xylene, hexanal served as attractants whereas non-host unique compounds, like 2-pentylfuran, 2-octenal acted as repellent. The results indicate that the rice unique compounds xylene, hexanal along with other volatile compounds could be responsible for higher preference of YSB towards rice plants. Similarly, the non-host unique compounds 2-pentylfuran, 2-octenal could possibly be responsible for lower preference and defence against YSB. These compounds could be utilised for devising traps for YSB monitoring and management.

Sex Pheromone of the Saturniid Moth Hemileuca nevadensis from Southern California.

The major and possibly only component of the sex attractant pheromone of the moth Hemileuca nevadensis (Lepidoptera: Saturniidae) from southern California was determined to be (E10,Z12)-hexadecadienal (E10,Z12-16:Ald). Detectable quantities of the analogs (E10,Z12)-hexadecadien-1-yl acetate (E10,Z12-16:Ac) and (E10,Z12)-hexadecadien-1-ol (E10,Z12-16:OH) were also present in solvent extracts of sex pheromone glands, and stimulated male antennae in coupled gas chromatography-electroantennogram detector (GC-EAD) assays. GC-EAD traces from solid phase microextraction (SPME) wipe samples of sex pheromone glands of calling females confirmed the presence of E10,Z12-16:Ald and traces of E10,Z12-16:OH on the gland surface, but E10,Z12-16:Ac was not detected. Despite evidence for the presence of all three compounds in extracts, behavioral responses to synthetic compounds in the field suggested that only E10,Z12-16:Ald is required for optimal attraction.

Comprehensive characterization of organics in oil sands process water in constructed mesocosms utilizing multiple analytical methods.

This study aims to provide a thorough characterization of dissolved organics in oil sands process water (OSPW) in field-based aquatic mesocosms at both molecular and bulk measurement levels using multiple analytical methods. In a 3-year outdoor mesocosm experiment, the analysis of naphthenic acid (NA) species was conducted using ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOFMS). The results revealed the removal of both total NAs (38% and 35%) and classical NAs (O2-NAs, 58% and 49%) in undiluted and half-diluted OSPW, respectively. The increased ratios of oxidized NAs (O3-O6 NAs) to classical NAs suggested a transformation trend. The results also indicated that O2-NAs with higher carbon number and lower double bond equivalent (DBE) were more easily degraded in the mesocosm systems. Biomimetic extraction using solid-phase microextraction (BE-SPME) measurement displayed 26% (undiluted OSPW) and 30% (half-diluted OSPW) decrease in total bioavailable organics over 3 years. Naphthenic acids fraction compounds (NAFCs) obtained by liquid-liquid extraction (LLE) were also determined using Fourier transform infrared spectroscopy (FTIR). Reduction in acute toxicity for undiluted (43%) and half-diluted (26%) OSPW was observed over 3 years, which are well correlated with the decreases of NAs and BE-SPME concentrations. Moreover, BE-SPME values were found to be linearly correlated with total NAs concentrations (r = 0.96) and NAFCs (r = 0.96). Additionally, the linear relationships of individual O2-O6 NA species and BE-SPME concentrations unveiled the changes in the relative abundances of O2-O6 NA species in total bioavailable organics over time in the mesocosms. The present study has provided comprehensive insights by integrating various analytical methods, contributing valuable information for assessing the effectiveness of aquatic mesocosm systems in studying the temporal changes of organics in OSPW.

Micro-Morphology characterization and HS-SPME-GC-MS Analysis of Floral parts of Quararibea funebris (La Llave) Vischer, traditionally known as Rosita de Cacao.

The flowers of Quararibea funebris are used to make a traditional drink called tejate, to which they add aroma, flavor and consistency. The study aims to profile the morphoanatomy of the floral parts of Q. funebris and analyze the changes in its volatile chemical composition during the drying process from 0 to 180 days by HS-SPME-GC-MS. The calyx, corolla, androecium, and gynoecium have distinct characteristics, such as non-glandular fused stellate trichomes, calcium oxalate crystals, and large secretory ducts. Histochemical localization reveals the presence of mucilage and total lipids in all parts of the flower. The chemical analysis of the essential oil, extracted from the flowers, showed that transfarnesol and geraniol were the most abundant compounds, with a yield of 0.04 %. HS-SPME analysis indicated that fresh flowers had a more complex composition than dried ones. In total, 31 components were identified. Nonanal and geranyl acetone were found to be distinctive components of dried flowers. Microscopic examination helps in identifying and authenticating raw materials and also reveals the presence of secretory ducts in all floral parts, which is a distinctive feature. The chemical profile of volatiles provides an important parameter for the evaluation of the quality of Rosita de Cacao raw materials.

Electrospun of functionalized mesoporous UiO-66 as the selective coating of solid phase microextraction Arrow for the determination of nine alkylphenols.

A solid-phase microextraction (SPME) Arrow and high-performance liquid chromatography-UV detector (HPLC-UV, detection at 225 nm) based method was developed for the selective determination of nine alkylphenols (APs) in milk. The functionalized mesoporous UiO-66 (4-meso-UiO-66) was utilized as the new coating material, which was synthesized by post-modification of pore-expanded UiO-66-NH2 by an esterification reaction with 4-pentylbenzoic acid. It was fully characterized by X-ray photoelectron spectroscopy (XPS), fourier transformation infrared spectrometry, nitrogen sorption-desorption test, scanning electron microscopy, transmission electron microscopy, and X-ray diffractometer. The characterization results showed the ester groups and benzene rings were introduced into the 4-meso-UiO-66, and the mesoporous structure was predominant in the 4-meso-UiO-66. The extraction mechanism of 4-meso-UiO-66 to APs is the synergistic effect of Zr-O electrostatic interaction and the size exclusion effect resulting from XPS, selectivity test, and nitrogen sorption-desorption test. The electrospinning technique was utilized to fabricate the 4-meso-UiO-66 coated SPME Arrow and polyacrylonitrile (PAN) was used as the adhesive. The mass rate of 4-meso-UiO-66 to PAN and the electrospinning time were evaluated. The extraction and desorption parameters were also studied. The linear range of this method was 0.2-1000 µg L-1 with a coefficient of determination greater than 0.9989 under the optimal conditions. The detection limits were 0.05-1 µg L-1, the inter-day and intra-day precision (RSD) were 2.8-11.5%, and the recovery was 83.6%-112%. The reusability study showed that the extraction performance of this new SPME Arrow could be maintained after 80 adsorption-desorption cycles. This method showed excellent applicability for the selective determination of APs in milk.

Direct Immersion-Solid Phase Microextraction for Therapeutic Drug Monitoring of Patients with Mood Disorders.

This article discusses a new method for monitoring drug concentrations in blood samples from patients with mood disorders. The method uses solid-phase microextraction to extract analytes directly from blood samples. It has been adapted to identify the most commonly used drugs in mood disorders, including amitriptyline, citalopram, fluoxetine, paroxetine, sertraline, trazodone, duloxetine, venlafaxine, lamotrigine, quetiapine, olanzapine, and mirtazapine. The analysis is carried out using high-performance liquid chromatography coupled with mass spectroscopy. The proposed DI-SPME/LC-MS method allows for a simple and quick screening analysis while minimizing the volume of the tested sample and solvent, in line with the principles of green analytical chemistry. The method was used to analyze 38 blood samples taken from patients with mood disorders, and drug concentrations were determined and compared with therapeutic and toxic dose ranges. This allowed for better control of the course of treatment.

Development of In-Needle SPME Devices for Microextraction Applied to the Quantification of Pesticides in Agricultural Water.

The chemical industry explosion in the 20th century has led to increased environmental pollution, affecting fauna, flora, and waterways. These substances alter water's taste, color, and smell, making it unfit for consumption or toxic. Agricultural water networks face threats from pollution before and after treatment. Some chemical contaminants, like pesticides, are embedded in natural biogeochemical cycles. In this study, we developed a simple and low-cost procedure for the fabrication of needles coated with polydimethylsiloxane (PDMS) as an efficient sorbent for the microextraction of organic pollutant traces from water. The prepared needles were used as an alternative for commercial solid-phase micro-extraction (SPME) devices in analytical chemistry. The PDMS polymeric phase was characterized by Fourier-transform infrared spectroscopy (FT-IR), thermogravimetry (TGA), and scanning electron microscopy (SEM). The PDMS-coated needles were used for extraction of thirteen pesticides by direct-immersion solid-phase microextraction (DI-SPME) from contaminated waters, followed by determination with gas chromatography-mass spectrometry (GC-MS). The developed analytical method showed limits of detection (LODs) between 0.3 and 2.5 ng mL-1 and RSDs in the range of 0.8-12.2%. The homemade needles were applied for the extraction of pesticides in surface and ground aqueous samples collected from an agricultural area. Several target pesticides were identified and quantified in the investigated water samples.

Evaluation of Aromatic Characteristics and Potential Applications of Hemerocallis L. Based on the Analytic Hierarchy Process.

Hemerocallis L. possesses abundant germplasm resources and holds significant value in terms of ornamental, edible, and medicinal aspects. However, the quality characteristics vary significantly depending on different varieties. Selection of a high-quality variety with a characteristic aroma can increase the economic value of Hemerocallis flowers. The analytic hierarchy process (AHP) is an effective decision-making method for comparing and evaluating multiple characteristic dimensions. By applying AHP, the aromatic character of 60 varieties of Hemerocallis flowers were analyzed and evaluated in the present study. Headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) was employed to identify volatile components in Hemerocallis flowers. Thirteen volatile components were found to contribute to the aroma of Hemerocallis flowers, which helps in assessing their potential applications in essential oil, aromatherapy, and medical treatment. These components include 2-phenylethanol, geraniol, linalool, nonanal, decanal, (E)-ß-ocimene, α-farnesene, indole, nerolidol, 3-furanmethanol, 3-carene, benzaldehyde and benzenemethanol. The varieties with better aromatic potential can be selected from a large amount of data using an AHP model. This study provides a comprehensive understanding of the characteristics of the aroma components in Hemerocallis flowers, offers guidance for breeding, and enhances the economic value of Hemerocallis flowers.

Effects of Non-Saccharomyces Yeasts and Their Pairwise Combinations in Co-Fermentation with Saccharomyces cerevisiae on the Quality of Chunjian Citrus Wine.

Non-Saccharomyces (NSc) yeasts have great potential in improving wine qualities. In this study, two NSc and two Saccharomyces cerevisiae (Sc) samples were tested on their performance of mono-inoculated and composite culture in the fermentation of Chunjian citrus wine. The cell count, Brix degree, total sugar, total acidity, alcohol level, pH value, color intensity (CI), and tonality were determined to evaluate the contribution of NSc to the quality of citrus wine in the mixed fermentation. Volatile compounds were analyzed by HS-SPME-GC-MS, and sensory evaluation was carried out. During the 9-day fermentation, the mixed-culture wine exhibited a higher cell concentration than the pure culture. After the fermentation, mixed-culture wine specifically decreased the concentrations of unfavorable volatile compounds, such as isobutanol and octanoic acid, and increased favorable volatile compounds, including ethyl octanoate, ethyl decanoate, and phenylethyl acetate. The quality category of the citrus wine was improved compared with the Sc mono-inoculated wines, mainly in regard to aroma, retention, and sweetness. The study shows that the mixed fermentation of NSc and Sc has positive impacts on reducing alcohol level and total acidity and increasing CI. The present work demonstrates that the mixed fermentation of NSc and Sc has enormous beneficial impacts on improving the quality of citrus wine.

Comprehensive Two-Dimensional Gas Chromatography with a TOF MS Detector-An Effective Tool to Trace the Signature of Grape Varieties.

Varietal volatile compounds are characteristic of each variety of grapes and come from the skins of the grapes. This work focuses on the development of a methodology for the analysis of free compounds in grapes from Trincadeira, Cabernet Sauvignon, Syrah, Castelão and Tinta Barroca from the 2021 and 2022 harvests, using HS-SPME-GC × GC-TOFMS. To achieve this purpose, a previous optimization step of sample preparation was implemented, with the optimized conditions being 4 g of grapes, 2 g of NaCl, and 2 mL of H2O. The extraction conditions were also optimized, and it was observed that performing the extraction for 40 min at 60 °C was the best for identifying more varietal compounds. The fiber used was a triple fiber of carboxen/divinylbenzene/polydimethylsiloxane (CAR/DVB/PDMS). In addition to the sample preparation, the analytical conditions were also optimized, enabling the adequate separation of analytes. Using the optimized methodology, it was possible to identify fifty-two free volatile compounds, including seventeen monoterpenes, twenty-eight sesquiterpenes, and seven C13-norisoprenoids. It was observed that in 2021, more free varietal volatile compounds were identifiable compared to 2022. According to the results obtained through a linear discriminant analysis (LDA), the differences in volatile varietal signature are observed both among different grape varieties and across different years.

Solid-Phase Microextraction/Gas Chromatography-Time-of-Flight Mass Spectrometry Approach Combined with Network Pharmacology Analysis to Evaluate the Quality of Agarwood from Different Regions against Anxiety Disorder.

Agarwood (Aquilaria malaccensis Lam.) is a resinous material from different geographical locations. The current evaluation of agarwood quality is usually based on its physical properties and chemical compounds, yet only a few studies have linked agarwood quality with its anxiolytic effect, as indicated by characteristic compounds. In this study, using solid-phase microextraction/gas chromatography-time-of-flight mass spectrometry (SPME/GC-TOFMS) and multivariate analysis, we found 116 significantly different compounds in agarwood samples from four locations in Southeast Asia with regard to their quality. Brunei and Nha Trang agarwood had abundant sesquiterpenoids, exhibiting notable pharmacological efficacy in relieving anxiety. Malaysian and Irian agarwood had abundant alcohols and aldehydes, qualifying them as high-quality spices. Compound-target-disease network and pathway enrichment analysis were further employed to predict 79 gene targets and 20 pathways associated with the anxiolytic effects based on the 62 sesquiterpenoids. The correlated relationships among the sesquiterpenoids and targets suggest that agarwood treats anxiety via multiple compounds acting on multiple targets. Varying levels of sesquiterpenes across agarwood groups might lead to differences in the anxiolytic effects via signaling pathways, such as neurotransmitter- and hormone-regulated pathways. Our study originally evaluates agarwood quality and its anxiolytic effect by linking the characteristic compounds to potential gene targets and pathways.

Comparison of Flavonoid Content, Antioxidant Potential, Acetylcholinesterase Inhibition Activity and Volatile Components Based on HS-SPME-GC-MS of Different Parts from Matteuccia struthiopteris (L.) Todaro.

Matteuccia struthiopteris is one of the most globally consumed edible ferns and widely used in folk medicine. Reports mainly focus on young fronds and the rhizome which are common edible medicinal parts. However, there are few detailed reports on other parts. Therefore, the volatile components of different parts based on HS-SPME-GC-MS were identified, and total flavonoid contents, antioxidant activities and acetylcholinesterase inhibitory activities were compared in order to reveal the difference of volatile components and potential medicinal value of different parts. The results showed that total flavonoid contents, antioxidant activities and volatile components of different parts were obviously different. The crozier exhibited the strongest antioxidant activities, but only underground parts exhibited a dose-dependent inhibition potential against AChE. Common volatile compounds were furfural and 2-furancarboxaldehyde, 5-methyl-. In addition, it was found that some volatile components from adventitious root, trophophyll, sporophyll and petiole were important ingredients in food, cosmetics, industrial manufacturing and pharmaceutical applications.

Profiling of Volatile Compounds in 'Muscat Hamburg' Contaminated with Aspergillus carbonarius before OTA Biosynthesis Based on HS-SPME-GC-MS and DLLME-GC-MS.

Aspergillus carbonarius is known to produce the carcinogenic ochratoxin A (OTA) in grapes. The metabolism process before OTA biosynthesis influences the content and composition of the volatile compounds in grapes. In this study, a self-established method based on QuEChERS coupled with high-performance liquid chromatography-fluorescence detection (HPLC-FLD) was used to determine the OTA levels during a seven-day contamination period. The results showed that OTA was detected on the second day after contamination with A. carbonarius. Thus, the first day was considered as the critical sampling timepoint for analyzing the volatiles in grapes before OTA biosynthesis. Additionally, the volatile compounds in grapes were analyzed using headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) and dispersive liquid-liquid microextraction gas chromatography-mass spectrometry (DLLME-GC-MS). The corresponding data were evaluated via multivariate data analysis using projection methods, including PCA and OPLS-DA. The results indicated significant differences in the nine volatile compounds in grapes contaminated with A. carbonarius before OTA biosynthesis. The results of the Pearson correlation analysis showed positive correlations between ethyl acetate, styrene, 1-hexanol and OTA; (E)-2-hexenal and nerolic acid were negatively correlated with OTA. Overall, these findings provide a theoretical basis for the early prediction of OTA formation in grape and grape products using GC-MS technology.

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.

Efficient Capture of Cannabis Terpenes in Olive Oil during Microwave-Assisted Cannabinoid Decarboxylation.

The development of selective extraction protocols for Cannabis-inflorescence constituents is still a significant challenge. The characteristic Cannabis fragrance can be mainly ascribed to monoterpenes, sesquiterpenes and oxygenated terpenoids. This work investigates the entrapment of Cannabis terpenes in olive oil from inflorescences via stripping under mild vacuum during the rapid microwave-assisted decarboxylation of cannabinoids (MW, 120 °C, 30 min) and after subsequent extraction of cannabinoids (60 and 100 °C). The profiles of the volatiles collected in the oil samples before and after the extraction step were evaluated using static headspace solid-phase microextraction (HS-SPME), followed by gas chromatography coupled to mass spectrometry (GC-MS). Between the three fractions obtained, the first shows the highest volatile content (~37,400 mg/kg oil), with α-pinene, ß-pinene, ß-myrcene, limonene and trans-ß-caryophyllene as the main components. The MW-assisted extraction at 60 and 100 °C of inflorescences using the collected oil fractions allowed an increase of 70% and 86% of total terpene content, respectively. Considering the initial terpene amount of 91,324.7 ± 2774.4 mg/kg dry inflorescences, the percentage of recovery after decarboxylation was close to 58% (mainly monoterpenes), while it reached nearly 100% (including sesquiterpenes) after extraction. The selective and efficient extraction of volatile compounds, while avoiding direct contact between the matrix and extraction solvents, paves the way for specific applications in various aromatic plants. In this context, aromatized extracts can be employed to create innovative Cannabis-based products within the hemp processing industry, as well as in perfumery, cosmetics, dietary supplements, food, and the pharmaceutical industry.

Fermentation Characteristics of Fermented Milk with Streptococcus thermophilus CICC 6063 and Lactobacillus helveticus CICC 6064 and Volatile Compound Dynamic Profiles during Fermentation and Storage.

The lactic acid bacteria Streptococcus thermophilus and Lactobacillus helveticus are commonly used as starter cultures in dairy product production. This study aimed to investigate the characteristics of fermented milk using different ratios of these strains and analyze the changes in volatile compounds during fermentation and storage. A 10:1 ratio of Streptococcus thermophilus CICC 6063 to Lactobacillus helveticus CICC 6064 showed optimal fermentation time (4.2 h), viable cell count (9.64 log10 colony-forming units/mL), and sensory evaluation score (79.1 points). In total, 56 volatile compounds were identified and quantified by solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS), including aldehydes, ketones, acids, alcohols, esters, and others. Among these, according to VIP analysis, 2,3-butanedione, acetoin, 2,3-pentanedione, hexanoic acid, acetic acid, acetaldehyde, and butanoic acid were identified as discriminatory volatile metabolites for distinguishing between different time points. Throughout the fermentation and storage process, the levels of 2,3-pentanedione and acetoin exhibited synergistic dynamics. These findings enhance our understanding of the chemical and molecular characteristics of milk fermented with Streptococcus thermophilus and Lactobacillus helveticus, providing a basis for improving the flavor and odor of dairy products during fermentation and storage.