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The present study was performed to determine the amount of polycyclic aromatic hydrocarbons (PAHs) and health risk in potato and related products (raw potato, fries potato, charcoal-grilled potato, gas-grilled potato, boiled potato and industrial potato chips) using the MSPE technique (magnetic solid phase extraction) and GC/MS method (gas chromatography-mass spectrometry). The results exhibited that the median of 16 PAHs was 10.63 µg/kg. Also, the median level of BaP (Benzo[a]pyrene) in samples was 0.07 µg/kg, which was less than standard level of the European Commission (maximum level of BaP in vegetables is 1 and in dried herbs is 10 μg/kg). The highest and lowest median level of ƩPAHs were evaluated in potato chips (19.28 μg/kg) and raw potatoes (6.31 μg/kg), respectively. The simulation of Monte Carlo used to estimate the indexes of Chronic Daily Intake (CDI) and Incremental Life Cancer Risk (ILCR). This results showed the rank order of the index of CDI according to percentile 95% was Nap > Ace > Acy > Ph > Fla > An > Chr > B(k)F > B(a)P. The cancer risk assessment exhibited PAHs in samples did not pose a serious concern to humans (ILCR<10−6), which were below the provisional maximum tolerable daily (10 ng/kg bw day−1). [ABSTRACT FROM AUTHOR]

Preen oil – the secretion from the uropygial gland of birds – may have diverse functions in avian reproduction: protection against eggshell bacteria, olfactory crypsis against nest predators and olfactory mate choice. To investigate such functions, we should first characterise variation in preen oil composition, but also confirm that previously described patterns are robust. Replication studies are crucial to test the reproducibility of previous findings, but are rarely undertaken in chemical ecology. Here, we conducted an almost exact replication of a previous study on the chemical composition of preen oil in a wild passerine bird, the pied flycatcher Ficedula hypoleuca. We aimed to estimate the reproducibility of the previous results using larger sample sizes and following a pre‐registered analysis. In addition, we explored the ontogeny of preen oil composition by comparing nestling and adult preen oil. In line with previous findings, preen oil composition was similar between breeding partners and not repeatable within individual females across breeding stages. Female preen oil changed across breeding stages more clearly than in the original study (higher richness, diversity and volatility during incubation than nestling‐rearing), further refuting a role of preen oil in olfactory crypsis in this species. Unlike the original study, we found no difference in chemical profiles between sexes (nestling‐rearing), casting doubt on the proposed role of preen oil as a sex semiochemical in this species. Nestling preen oil differed from adults, was more similar to adult males than to adult females, but was not more similar to parents than to non‐parents. We found family chemical signatures, which, along with the breeding pair signature, suggests an influence of the nest environment on preen oil composition. Our study highlights the importance of replication and provides novel insights into the function and development of preen oil. [ABSTRACT FROM AUTHOR]

AbstractThe utilization of celery seeds as seasonings and in herbal teas is widespread due to their significant nutritional and medicinal value. The determination of volatile organic compounds (VOCs) is a valuable tool for species identification and classification. Currently, there is an absence of information investigating the volatile constituents present in the cultivars of celery seeds. To analyze the varietal differences of celery seeds, VOCs were isolated using headspace solid-phase microextraction with by determination by gas chromatography-mass spectrometry. The samples underwent further comparison using multivariate statistical analysis to determine the changes in VOCs. Cluster analysis and principal component analysis were used to conduct correlation measurements on the samples. An orthogonal partial least squares discriminant analysis (OPLS-DA) model was developed to discriminate between samples and identify differential compounds. The distribution of these key compounds in these seeds was analyzed using a Sankey diagram. The samples contained 30 volatile components, mainly terpenes and esters. Correlation analysis revealed distinct variations in the VOCs. Furthermore, the utilization of the OPLS-DA model facilitated the identification of 11 differential compounds. The Sankey diagram illustrated significant disparities in the distribution patterns of these key compounds in the celery seeds. [ABSTRACT FROM AUTHOR]

ABSTRACT Shanxi aged vinegar (SAV) is a traditional vinegar produced mainly in southern China from rice and wheat, undergoing prolonged fermentation for maturation, which distinguishes it from other vinegar. To explore its flavour, a selection of 12 SAV varieties was meticulously chosen for in‐depth aroma analysis. Sensory analysis and electronic nose (E‐nose) were used to compare flavour profiles. Volatile components were extracted via liquid–liquid extraction (LLE) with solvent‐assisted flavour evaporation (SAFE), analysed by gas chromatography–mass spectrometry (GC–MS) and gas chromatography olfactometry‐mass spectrometry (GC‐O‐MS). The results revealed 145 volatile compounds, predominantly acids, alcohols, ketones and heterocycles, with acids as the most prevalent (ranging from 960.17 to 1231.78 μg/mL). Additionally, 90 aroma‐active compounds were identified, notably acetic acid, furfuryl alcohol, 2,3‐dimethylpyrazine, lactic acid, phenol, propyl acetate, ethyl propionate and 2(5H)‐furanone. Accordingly, a flavour wheel was constructed highlighting dominant volatile components, featuring acidic, alcohol, tangerine peel‐like and yeasty aromas. Partial least squares regression (PLSR) analysis showed that the acidity note in SAV positively correlates with acetic acid, isovaleric acid, hexanoic acid, phenethyl alcohol and butyric acid. Understanding the flavour composition of SAV provides vital insight for flavour research and product quality control. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study is to develop and optimize a method for evaluating the persistence of residual fragrance after body washing, addressing a significant requirement in the development of personal care products. The main objective is to establish a reliable, sensitive and reproducible analytical technique to assess fragrance longevity on skin post‐use of body wash products. Methods: Headspace solid‐phase microextraction (HS‐SPME) coupled with gas chromatography–mass spectrometry (GC–MS) is used to analyse residual fragrances. We investigate the extraction efficiencies of various SPME fibres and compare different methods for sampling skin‐emitted fragrances, including tape stripping and sealed glass funnels. A controlled body‐washing procedure is implemented to standardize the cleansing process. Results: Our findings indicate that the relative standard deviation for measuring five distinct fragrances is within the range of 3%–14%, highlighting the precision of the method. A notable variance exists in the extraction efficiency of fragrances using different types of SPME fibres, with some exhibiting over a threefold difference. Furthermore, the glass funnel method for fragrance collection demonstrates an 11.7 times greater sensitivity to galaxolide than that of the tape‐stripping method. Residual fragrances with base notes as the main components can be detected on the skin up to 24 h after body washing. Conclusion: The optimized method for residual fragrance evaluation developed in this study offers a robust tool for analysing fragrance components persisting on the skin for up to 24 h post‐wash. This advancement facilitates a deeper understanding of fragrance longevity in personal care products, enabling comparative analyses between different products. [ABSTRACT FROM AUTHOR]

In the field of chemical warfare agents (CWAs), ethanolamines are important building blocks for the preparation of nerve agents belonging to the V-series such as VX and VR as well as the nitrogen-based mustards. In this work, the determination of three members in this class of Schedule 2B reportable chemicals, namely N,N-dimethylethanolamine (DMEA), N,N-diethylethanolamine (DEEA), and N,N-diisopropylethanolamine (DIEA) by electron ionization gas chromatography-mass spectrometry (EI-GC-MS) is presented. The three dialkylethanolamines were spiked in a high organic content soil matrix featured during the 45th Organization for the Prohibition of Chemical Weapons (OPCW) proficiency test (PT) at two separate concentrations each (1 and 10 µg/g separately), simulating values often encountered during these tests. The N,N-dialkylethanolamines were O-alkylated using benzyl bromide and sodium carbonate at 55 °C and were detected as their benzylated versions by electron ionization GC-MS. The benzylation of each dialkylethanolamine yielded derivatives with higher molecular weight and therefore different GC-MS profiles such as longer retention times and sharper peak chromatography relative to their unmodified counterparts. These characteristics enable the analytical chemist to detect and confirm these important CWA-related chemicals specifically in instances where they are present in low concentrations (i.e. <10 µg/g) among more abundant interferences. [ABSTRACT FROM AUTHOR]

[Objective] A method for simultaneous determination of ẞ-sitosterol, stigmasterol, campesterol and brassicasterol in edible oil was established by gas chromatography-mass (GC-MS). [Method] Sample was saponified by potassium hydroxide-ethanol solution, n-hexane extraction, concentration, derivatization, and then diluted with n-hexane.GC-MS was used to select ion scanning mode (SIM) and external standard method was used for quantification. [Result] There were good linear relationships for ẞ-sitosterol, stigmasterol, brassicasterol in 5-500 µg/mL, and campesterol in 2.5-250.0 µg/mL, respectively. Linear correlation coefficients (R²) were greater than 0.999. Limits of detection were 0.05- 0.10 mg/kg and limits of quantification were 0.1-0.3 mg/kg, respectively. Adding standard recovery rate was 80.5%-107.8%, relative standard deviation (RSD) was 2.3%-9.8%. [Conclusion] This method is easy to operate, efficient, highly sensitive, and has good repeatability, which is suitable for the determination of ẞ-sitosterol, stigmasterol, campesterol and brassicasterol contents in edible vegetable oil samples. [ABSTRACT FROM AUTHOR]

Lonicera japonica is a commonly used Chinese herbal medicine, but few studies have focused on its pesticide residues. In this study, a quick, easy, cheap, effective, rugged, safe (QuEChERS) pretreatment combined with gas chromatography-mass spectrometry (GC-MS) was established to determine 16 pesticides in L. japonica. Various factors including the type and volume of extraction solvent, times of ultrasound-assisted extraction, and type and weight of purifying agents were optimized. The established method showed good linearity with correlation coefficient (r) > 0.99 within the range of 0.01–5.0 mg·L−1, and average recoveries (AR) were 82.3%-102.5% at spiking levels of 0.01, 0.1, and 0.5 mg·kg−1 with relative standard deviations (RSD) of 0.43%-4.75%. Only bifenthrin and fenvalerate can be detected with maximum detected concentrations of 1.41 and 0.13 mg·kg−1. The results showed that the established method can be applied to detect pesticide residues in L. japonica with potential applications for other Chinese herbal medicines. [ABSTRACT FROM AUTHOR]

This study investigates the volatolome in an individual with chromhidrosis, utilizing solid-phase microextraction (SPME) and pentane extraction, followed by gas chromatography–mass spectrometry (GC-MS), to identify key volatile organic compounds (VOCs). A total of 31 compounds were identified, including aldehydes, fatty acid esters, and benzoic acid derivatives. SPME was more effective in capturing highly volatile compounds, while pentane extraction primarily isolated lipophilic substances such as squalene and cholesterol. The findings suggest that lipid peroxidation and metabolic dysregulation contribute to the formation of lipofuscin, the pigment responsible for colored sweat. Additionally, the detection of 9-octadecenamide and benzoic acid derivatives highlights the role of oxidative processes in chromhidrosis. [ABSTRACT FROM AUTHOR]

The significance of Thymus species in the scientific community is growing steadily due to their extensive utilization in traditional medicine, food industry, and pharmaceutical sector, owing to their abundance in essential oil and phytochemical content, rendering them commercially significant species. The current work focuses on conducting a comprehensive analysis of the ethanol extract and essential oil derived from the root and aerial portions of Thymus brachychilus Jalas, an endemic species that has not been previously investigated. Additionally, a novel GC-MS (gas chromatography–mass spectrometry) technique was developed to quantify the levels of triterpenoids, which are frequently found in many plants, particularly those belonging to the Lamiaceae family. The approach was then used to assess the triterpenoid content of the species. While the phenolic content of the species was determined by LC-MS/MS (liquid chromatography–tandem mass spectrometry), the chemical composition of triterpenoid, essential oil and flavor (aroma) of the plant was determined by GC-MS. Eucalyptol was the primary ingredient in both the essential oil and the flavor, accounting for 11.05% and 12.35%, respectively. In the DPPH and ABTS radical scavenging techniques, the root ethanol extract exhibited the greatest antioxidant activity with IC50 values of 26.70 ± 0.23 and 19.16 ± 0.11 µg/mL, respectively. There was a high level of urease (59.54 ± 1.67% at 100 µg/mL) inhibitory activity observed in the root ethanol extract in enzyme inhibition assays, as well as angiotensin (94.80 ± 0.56%), elastase (40.19 ± 0.39%), and collagenase (48.26 ± 0.12%) inhibition in the aerial ethanol extract. Moreover, the MCF-7 cell line for breast cancer had a strong cytotoxic impact when exposed to the essential oil of the species (vitality%: 1.45 ± 0.01 at 200 µg/mL. The LC-MS/MS and GC-MS studies revealed that the roots had a significant concentration of rosmarinic acid (15,801 µg analyte/g extract), but the aerial portions had a substantial quantity of ursolic acid (152,374 µg analyte/g extract). The plant exhibits potential in the food, cosmetic, and pharmaceutical sectors on account of its elevated levels of rosmarinic and ursolic acid, superior antioxidant capacity, and angiotensin and urease inhibitory effect. [ABSTRACT FROM AUTHOR]

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AbstractAn extraction protocol from silt sediment of fentanyl and three analogs: acetylfentanyl, thiofentanyl and acetylthiofentanyl, spiked at two concentrations each and separately (at ∼1 and ∼10 µg/g), is described. In addition, the identity of the fentanyls preliminarily identified by electron ionization gas chromatography-mass spectrometry (EI-GC-MS) analysis, can be corroborated by reacting each opioid in the silt’s extract with 2,2,2-trichloroethoxycarbonyl chloride (Troc-Cl). Reaction between Troc-Cl and each opioid generates two unique products that can be used to retrospectively identify the original opioid therefore serving as a corroborating tool for known opioids as well as new, unknown fentanyl analogs. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

AbstractA simple needle-trap device (NTD) coupled with gas chromatography-mass spectrometry (GC-MS) was developed to determine trace levels of nitrobenzenes (NBs) in workplace air. The NTD with sorbent inside the needle was employed for the quantification of nitrobenzene, o-nitrotoluene, m-nitrotoluene, p-nitrotoluene, o-nitrochlorobenzene, m-nitrochlorobenzene, and p-nitrochlorobenzene. The optimum temperature and time for desorption of analytes were 270 °C and 4 min, and parameters such as sampling flow rate, breakthrough volume, and storage capability were also optimized. The limits of detection and quantification were in the ranges of 1.8 × 10−4–1.1 × 10−3 and 5.9 × 10−4–3.6 × 10−3 mg m−3, respectively. The developed protocol was successfully applied for the determination of NBs in vehicle repair plants where the highest detected concentration was 0.11 mg m−3. The established NTD-GC-MS generally applies to monitoring trace levels of NBs in the air. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Condiment is the property of China Condiment and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this experiment, five different parts of beef were selected to make boletus beef sauce, namely beef hind leg (BHL), beef shoulder (BS), beef knuckle (BK), beef brisket (BB), and beef tendon (BT), and the effects of different beef parts on the quality and volatile aroma components of spicy beef boletus sauce were investigated. The boletus beef sauce made from BB reported the highest sensory score of 87.4. In terms of texture, beef sauce made from BB exhibited the best quality, with hardness, elasticity, gumminess, and chewiness values of 14.01 N, 4.71 mm, 3.22 N, and 15.30 mJ, respectively. Significant differences (P<0.05) in color of beef sauce were observed among different beef parts based on the L* and a* values. Electronic nose could effectively distinguish the spicy beef boletus sauce made from different parts of beef. In terms of flavor substances, 84 volatile flavor substances were detected in BHL, 36 in BS, 52 in BT, 102 in BK, and 87 in BB. The main aroma components were consistent with the types of sensitive substances identified by the electronic nose. Among them, hexanal, D-limonene, α-pinene, diallyl disulfide, and anethole were the common aroma components in the five parts, with ROAV>1. In summary, the BB was proven to be the best raw material in making spicy beef boletus sauce. These research findings provide a theoretical basis and data reference for the future cooking process and flavor characteristics of beef sauce. [ABSTRACT FROM AUTHOR]

Metabolomics analysis was conducted using gas chromatography-mass spectrometry (GC-MS) data, employing principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). Two hundred samples of purple-skinned garlic from five regions (Yunnan, Shandong, Henan, Anhui, and Jiangsu) were analyzed. Three preprocessing methods encompassing maximum-minimum normalization (MMS), standardization of standard deviation (SS), and standard normal variate transform (SNV) were used. Five machine learning models including random forest (RF), support vector machine (SVM), XGBoost, convolutional neural network (CNN), and long short-term memory neural network (LSTM) were utilized to classify and discriminate the origin of garlic. The analysis revealed 66 metabolites screened across garlic samples from different origins, with 12 differential metabolites identified through PLS-DA analysis. These metabolites were associated with 6 metabolic pathways: valine, leucine, and isoleucine biosynthesis, galactose metabolism, cyanoamino acid metabolism, glyoxylate and dicarboxylic acid metabolism, glycine, serine, and threonine metabolism, D-amino acid metabolism. Among the five machine learning models, LSTM exhibited the best performance, achieving 100% accuracy on the test set across three preprocessing methods. This study based on the combination of metabolomics and LSTM, a type of machine learning, demonstrates high accuracy and reliability in identifying the origin of garlic, providing a reliable technical means for tracing the source of garlic products.

To evaluate the effects of long-term frozen storage on the flavor quality of Rosa roxburghii juice, sensory evaluation, electronic nose, and headspace solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) were utilized to analyze the dynamic changes of sensory and aroma characteristics of Rosa roxburghii juice at −20 ℃ for various storage times(0, 2, 4, 6, 8 M). The results revealed the identification of a total of 127 volatile compounds, the majority of which were alcohols (31), hydrocarbons (34), and esters (24). The contents of 1-hexanol, (Z)-3-hexen-1-ol, 1-octene-3-ol, linalool, 1-octanol, α-copaene, ethyl hexanoate, ethyl octanoate, and methyl eugenol decreased over time, indicating that the fragrance of green grass, fruit, and flowers may diminish over time. The concentration of nonanal increased substantially (P

In this experiment, five different parts of beef were selected to make boletus beef sauce, namely beef hind leg (BHL), beef shoulder (BS), beef knuckle (BK), beef brisket (BB), and beef tendon (BT), and the effects of different beef parts on the quality and volatile aroma components of spicy beef boletus sauce were investigated. The boletus beef sauce made from BB reported the highest sensory score of 87.4. In terms of texture, beef sauce made from BB exhibited the best quality, with hardness, elasticity, gumminess, and chewiness values of 14.01 N, 4.71 mm, 3.22 N, and 15.30 mJ, respectively. Significant differences (P1. In summary, the BB was proven to be the best raw material in making spicy beef boletus sauce. These research findings provide a theoretical basis and data reference for the future cooking process and flavor characteristics of beef sauce.

In order to investigate the differences in volatile substances of bighead carp (Aristichthys nobilis) meat from various habitats, gas chromatography-mass spectrometry (GC-MS) was employed to detect and compare the volatile substances of bighead carp meat from five different habitats, including Hongmen Reservoir, Junshan Lake, Zhelin Lake, Datang Reservoir, and Nanxin culture pond. The results showed that a total of 56 volatile substances were detected in bighead carp meat from five habitats, including 12 aldehydes, 8 ketones, 15 alcohols, 8 hydrocarbons, 13 aromatic and other substances. Moreover, hexyl aldehyde, heptyl aldehyde, nonyl aldehyde, n-hexyl alcohol, 1-octene-3-alcohol, and heptadecane were common chemicals found in bighead carp meat of all habitats. Utilizing relative odor activity value (ROAV), aldehydes, alcohols, and phenols were identified as the key odor substances in bighead carp meat. Cluster analysis (CA) and principal component analysis (PCA) results showed the cumulative contribution rate of PC1 and PC2 reached 73.5%. Moreover, the volatile substance composition and odor of bighead carp meat from macro-aquatic habitats were similar. Meanwhile, the odor was significantly better than that of bighead carp meat from high-density aquaculture habitats. On the whole, significant differences were observed in the composition, content of volatile compounds, and key odor substances among bighead carp meat from different habitats (P

Fusarium graminearum is the main pathogenic fungus causing wheat head blight. It not only causes severe crop yield reduction, but also produces fungal toxins such as deoxynivalenol (DON) and 15-acetyl deoxynivalenol (15-ADON), which are dangerous food pollutants to people and livestock. For the genetic functional study of Fusarium graminearum, it is often necessary to culture mycelium on LTB medium in the laboratory to investigate its regulatory effect on DON and 15-ADON synthesis. However, the detection of DON and 15-ADON in the mycelium is focused on extracellular, with less focus on the detection of intracellular. Simultaneous detection of intracellular and extracellular DON and 15-ADON can provide more in-depth information of fungal toxin production and secretion functions. In the study, a method based on gas chromatography-mass spectrometry (GC-MS) for simultaneous detection of DON and 15-ADON was developed. The solvents for extracting DON and 15-ADON can be completely separated and the calibration curves of each extract show good linear relationship within a certain range. The mass spectrometric characteristic scan shows high ionization efficiency for both DON and 15-ADON. The retention time of DON and 15-ADON in chromatogram are 6.98 and 7.68 min, respectively. Qualitative analysis of DON was performed using m/z 295, 235, and 193 under single ion monitor (SIM) mode, while m/z 392, 235, and 193 were used for 15-ADON. The highest intensity ion m/z 235 was selected for the quantification of DON, and m/z 193 for the quantification of 15-ADON. This method was used to detect the intracellular and extracellular levels of DON and 15-ADON in wild-type PH-1 and tri5 mutant with DON biosynthesis deficiency. The intracellular DON and 15-ADON levels in PH-1 are determined to be (149.13±9.15) μg/g and (1833.31±185.33) μg/g, extracellular levels are (5910.35±468.23) μg/g and (45222.12±2726.81) μg/g, respectively. The study identified a mutant strain with the deletion of the first enzyme involved in the synthesis pathway of DON and 15-ADON，both DON and 15-ADON are not detected in the extracellular and intracellular of the tri5 mutant. Additionally, this research confirms that after 7 days of cultivation in LTB medium, the wild-type strain exhibits higher levels of 15-ADON in both intracellular and extracellular compared to DON, with extracellular levels of DON and 15-ADON being higher than intracellular levels. This method can provide a methodological reference for the functional study of toxin synthesis in Fusarium graminearum.

A method of combining headspace microextraction technique based on a polyurethane sponge-supported liquid film with gas chromatography-mass spectrometry (GC-MS) was developed for convenient and sensitive analysis of six polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. The microextraction device consists of three parts, namely injector, polyurethane sponge, and headspace bottle. Firstly, the commercially available polyurethane sponge was specially tailored to be fitted into miniature cylinders that were compatible with the internal cavity of the 2.5 mL syringe needle. Then the extraction solvents were loaded to form a microextraction liquid film on the surface and inside of the sponge. After sealed with syringe barrel, the syringe needle was inserted into the septum of headspace bottle for headspace microextraction. The dynamic suction, heating assistance, and magnetic stirring were adopted to accelerate the volatilization process and transferring of the analytes in gas-liquid interface. Given the excellent elasticity of polyurethane sponge, the extraction solution could be successfully recovered through solvent elution and physical extrusion. The influence of the types and amounts of extraction solvents, suction time, heating (extraction) temperatures, stirring speeds, and eluent volumes on the enrichment efficiency of the monitored PAHs were systematically investigated. The results indicated that the satisfactory extraction efficiency could be achieved by using 40 µL of carbon tetrachloride as an extractant, which were loaded into a polyurethane sponge microcylinder with a bottom diameter and height of 4 mm, and followed by 150 cycles dynamic suction under extraction conditions of 65 ℃ and 1 000 r/min. Subsequently, physical extrusion was adopted to collect the extraction solution after elution with 30 µL of carbon tetrachloride. The validation results demonstrated that the proposed method achieves good relative recoveries of PAHs ranging from 94.7% to 113.2% at three spiked levels of 0.1, 0.5, and 1 μg/L. The intra- and inter-day precisions are in the range of 1.0%-8.1% and 4.2%-9.5%, respectively. Good linearities are observed for all monitored PAHs with the regression coefficients (R2) greater than 0.997 in the concentration range of 0.01-5 μg/L. The limits of detection (LODs) and quantification (LOQs) are in the range of 3-30 ng/L and 10-100 ng/L, respectively. This method is easy to operate, and has the advantages of low cost, high sensitivity as well as fast speed, having highly potential in the field of trace volatile analysis in environmental samples.

To explore the quality and material basis of Shoumei white tea from different varieties of tea trees, in this study, Shoumei white tea made from the raw materials of Fu'an Da Bai (FA), Fuding Da Hao (FD), Meizhan (MZ) and Fengqing Da Ye Zhong (FQ) were analyzed for their quality using sensory evaluation, high performance liquid chromatography (HPLC), headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). Orthogonal partial least squares discriminant analysis (OPLS-DA) and its permutation test were used to distinguish the differences among the samples, and variables were selected based on the variable importance in projection (VIP) values and P-values. The results indicated that there were differences in both sensory evaluation and physicochemical properties among the white teas processed from the four varieties of tea trees. Each of the Shoumei white teas from the four varieties of tea trees exhibited good sensory qualities and distinct characteristics. The water extract content of the different Shoumei white teas ranged from 45.48% to 46.89%, the tea polyphenol content ranged from 16.79% to 19.96%, the caffeine content ranged from 41.34 to 56.61 mg/g, the total theaflavin content ranged from 3.31 to 8.22 mg/g, the total catechin content ranged from 143.90 to 165.62 mg/g, the non-esterified catechin content ranged from 21.55 to 36.01 mg/g, the esterified catechin content ranged from 114.14 to 134.16 mg/g, and the total free amino acid content ranged from 30.35 to 38.31 mg/g. Furthermore, differences in the content of non-volatile compounds were observed among the different tea samples. A total of 57 volatile compounds were detected in the four tea samples, with a total concentration ranging from 121.63 to 203.43 μg/g. Among them, alcohols and aldehydes accounted for the majority. Significant differences were observed among the tea samples in terms of the aroma profile, types, and concentrations of volatile compounds. OPLS-DA based on 93 compounds from the four tea samples was employed to effectively differentiate between the tea samples and identify 56 differentiating compounds (VIP>1 and P

[Objective] This study aimed to investigate the chemical constituents of walnut leaves. [Methods] The volatile components of walnut leaves were analyzed by head-space solid micro-extraction and coupled with GC-MS. The chemical composition of ethanol extract was identified using ultra-high performance liquid chromatography coupled with quadrupole Orbitrap high resolution mass spectrometry (UPLC-Q-Exactive). [Results] 88 kinds of volatile compounds were identified in walnut leaves, mainly terpenoids, of which sesquiterpenoids account for 78.35%. 30 kinds of active components were identified from ethanol extracts, including twenty kinds of polyphenols (twelve kinds of flavonoids), four kinds of phenylpropanoids, three kinds of pentacyclic triterpenoids, two kinds of essential amino acids and 1 tricarboxylic acid compounds in the ethanol extract in walnut leaves. [Conclusion] The combined use of SPME-GC-MS and UPLC-Q Exactive technology can determine and analyze the chemical composition of walnut leaves systematically, accurately and rapidly.

A method of gas chromatography-mass spectrometry (GC-MS) was established to determine the migration of dibutyl sebacate, dioctyl sebacate, diisooctyl sebacate, decanedioic acid bis(2,2,6,6-tetramethyl-4-piperidinyl)ester in water-based, acidic and alcoholic food simulants, and olive oil and chemical alternative solvents. The 95% ethanol and isooctane chemical substitution solutions were directly analyzed by GC-MS. The olive oil samples were extracted with acetonitrile followed by QuEChERS purification, and then analyzed by GC-MS. Other simulants (water, 4% acetic acid, 10% ethanol, 20% ethanol, and 50% ethanol) were extracted with n-hexane and then determined by GC-MS. The results showed that the method is well performed under optimized conditions, with the correlation coefficient (r2) greater than 0.995. The limits of detection and the limits of quantitation of the four sebacic acid ester compounds in water, 4% acetic acid, 10% ethanol, 20% ethanol, 50% ethanol, 95% ethanol, isooctane, and olive oil simulants are 0.1-0.2 mg/kg, 0.3-0.5 mg/kg, respectively. Migration experiments on plastic samples were conducted, and spiking experiments at three concentration levels of 0.30, 2.0, 4.0 mg/kg in water, 4% acetic acid, 10% ethanol, 20% ethanol, 50% ethanol, 95% ethanol, and isooctane food simulants, and three concentration levels of 0.50, 2.0, 4.0 mg/kg in olive oil food simulants were carried out. The spiking recoveries range from 92.5% to 108%, and the relative standard deviations (RSDs) are 2.4%-8.8%. The method solves the problem that decanedioic acid bis(2,2,6,6-tetramethyl-4-piperidinyl)ester cannot be extracted into n-hexane in 4% acetic acid by adjusting pH value using ammonium hydroxide, the optimal pH range was determined by comparing the responses of four targets at different pH values. QuEChERS was firstly used for migration experiments of sebacic acid esters in food contact materials to solve the turbidity and partial oil precipitation of olive oil simulants in the concentration process after extraction. By optimizing the QuEChERS filling material, the interference of organic acids, fatty acids, sugar and other impurities on the targets were reduced, producing greater separation effect of the targets. The separation efficiency of four chromatographic columns with different polarity was compared, and the DB-17HT column was selected to detect the four sebacic acid esters simultaneously. Plastics such as polypropylene, polyethylene terephthalic acid terephthalate, polyvinyl chloride, composite membranes, paper cups, recycled PET and recycled PVC were collected and migration experiments were carried out, the migration of sebacic acid esters in these plastics materials was investigated. This method is highly sensitive, precise, and accurate, fully meeting the requirement for determining the migration of the sebacic acid esters in food contact materials and their products.

Five kinds of commercially available sour fish sauce were taken as the research object to clarify their quality and flavor characteristics. The physicochemical and nutritional indexes, free amino acids, and volatile components were analyzed. The results showed that the moisture, ash, total acid, amino acid nitrogen, reducing sugar, protein, vitamin C and fat contents in the five kinds of sour fish sauce were significantly different (P

Douchi is a highly appreciated product due to its unique flavor, high nutritional value, and health benefits. Douchi from different regions exhibits distinct characteristics. The objective of this study was to investigate the volatile profiles in douchi produced from different geographical origins using gas chromatography-mass spectrometry (GC-MS) and chemometrics. The volatiles were extracted by headspace solid-phase micro-extraction (HS-SPME) and subsequently determined by GC-MS. A comparative analysis was further conducted to identify the variations in volatile compounds among the samples. The correlation between the samples was investigated by employing cluster analysis (CA) and principal component analysis (PCA). An orthogonal partial least squares-discriminant analysis (OPLS-DA) model was established to discriminate samples from different regions and identify key differential compounds. A total of 46 volatile compounds were detected, among which terpenes, alcohols were the main compounds. Furthermore, 14 key differentiating compounds were screened out based on the OPLS-DA modle. The application of GC-MS combined with chemometrics offers a theoretical framework for douchi quality control and classification. [ABSTRACT FROM AUTHOR]

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A method of combining headspace microextraction technique based on a polyurethane sponge-supported liquid film with gas chromatography-mass spectrometry (GC-MS) was developed for convenient and sensitive analysis of six polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. The microextraction device consists of three parts, namely injector, polyurethane sponge, and headspace bottle. Firstly, the commercially available polyurethane sponge was specially tailored to be fitted into miniature cylinders that were compatible with the internal cavity of the 2.5 mL syringe needle. Then the extraction solvents were loaded to form a microextraction liquid film on the surface and inside of the sponge. After sealed with syringe barrel, the syringe needle was inserted into the septum of headspace bottle for headspace microextraction. The dynamic suction, heating assistance, and magnetic stirring were adopted to accelerate the volatilization process and transferring of the analytes in gas-liquid interface. Given the excellent elasticity of polyurethane sponge, the extraction solution could be successfully recovered through solvent elution and physical extrusion. The influence of the types and amounts of extraction solvents, suction time, heating (extraction) temperatures, stirring speeds, and eluent volumes on the enrichment efficiency of the monitored PAHs were systematically investigated. The results indicated that the satisfactory extraction efficiency could be achieved by using 40 µL of carbon tetrachloride as an extractant, which were loaded into a polyurethane sponge microcylinder with a bottom diameter and height of 4 mm, and followed by 150 cycles dynamic suction under extraction conditions of 65 ℃ and 1 000 r/min. Subsequently, physical extrusion was adopted to collect the extraction solution after elution with 30 µL of carbon tetrachloride. The validation results demonstrated that the proposed method achieves good relative recoveries of PAHs ranging from 94.7% to 113.2% at three spiked levels of 0.1, 0.5, and 1 μg/L. The intra- and inter-day precisions are in the range of 1.0%-8.1% and 4.2%-9.5%, respectively. Good linearities are observed for all monitored PAHs with the regression coefficients (R²) greater than 0.997 in the concentration range of 0.01-5 μg/L. The limits of detection (LODs) and quantification (LOQs) are in the range of 3-30 ng/L and 10-100 ng/L, respectively. This method is easy to operate, and has the advantages of low cost, high sensitivity as well as fast speed, having highly potential in the field of trace volatile analysis in environmental samples. [ABSTRACT FROM AUTHOR]

Fusarium graminearum is the main pathogenic fungus causing wheat head blight. It not only causes severe crop yield reduction, but also produces fungal toxins such as deoxynivalenol (DON) and 15-acetyl deoxynivalenol (15-ADON), which are dangerous food pollutants to people and livestock. For the genetic functional study of Fusarium graminearum, it is often necessary to culture mycelium on LTB medium in the laboratory to investigate its regulatory effect on DON and 15-ADON synthesis. However, the detection of DON and 15-ADON in the mycelium is focused on extracellular, with less focus on the detection of intracellular. Simultaneous detection of intracellular and extracellular DON and 15-ADON can provide more in-depth information of fungal toxin production and secretion functions. In the study, a method based on gas chromatography-mass spectrometry (GC-MS) for simultaneous detection of DON and 15-ADON was developed. The solvents for extracting DON and 15-ADON can be completely separated and the calibration curves of each extract show good linear relationship within a certain range. The mass spectrometric characteristic scan shows high ionization efficiency for both DON and 15-ADON. The retention time of DON and 15-ADON in chromatogram are 6.98 and 7.68 min, respectively. Qualitative analysis of DON was performed using m/z 295, 235, and 193 under single ion monitor (SIM) mode, while m/z 392, 235, and 193 were used for 15-ADON. The highest intensity ion m/z 235 was selected for the quantification of DON, and m/z 193 for the quantification of 15-ADON. This method was used to detect the intracellular and extracellular levels of DON and 15-ADON in wild-type PH-1 and tri5 mutant with DON biosynthesis deficiency. The intracellular DON and 15-ADON levels in PH-1 are determined to be (149.13±9.15) μg/g and (1 833.31±185.33) μg/g, extracellular levels are (5 910.35± 468.23) μg/g and (45 222.12±2 726.81) μg/g, respectively. The study identified a mutant strain with the deletion of the first enzyme involved in the synthesis pathway of DON and 15-ADON，both DON and 15-ADON are not detected in the extracellular and intracellular of the tri5 mutant. Additionally, this research confirms that after 7 days of cultivation in LTB medium, the wild-type strain exhibits higher levels of 15-ADON in both intracellular and extracellular compared to DON, with extracellular levels of DON and 15-ADON being higher than intracellular levels. This method can provide a methodological reference for the functional study of toxin synthesis in Fusarium graminearum. [ABSTRACT FROM AUTHOR]

To investigate the nephrotoxic effect and related pathway evaluation of Yiguan Decoction on rats using gas chromatography-mass spectrometry (GC-MS) metabolomics method. A blank group, a model group, and a consistently high, medium, and low dose administration group were set up, with rats continuously gavaged for 21 days. GC-MS technology was used to analyze the serum of rats in each group and obtain differential metabolite information. Principal component analysis (PCA) was used to classify the metabolites in the blank group and model group, and the differential metabolites and changes in content in the serum of rats with Yiguan Decoction intervention were searched and analyzed. The results show that pathological sections of the kidneys of rats in the Yiguan Decoction high, medium, and low dose groups show varying degrees of damage. The metabolic profile of the high-dose group rats approach that of the model group. 16 differential metabolites in serum were identified. The three main metabolic pathways involved in the Yiguan Decoction are: biosynthesis of phenylalanine, tyrosine, and tryptophan, sulfur metabolism, and glyceride metabolism. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are continuously emitted into the atmosphere from natural and anthropogenic sources and rapidly spread from the atmosphere to different environments. A large group of VOCs has been included in the class of air pollutants; therefore, their determination and monitoring using reliable and sensitive analytical methods represents a key aspect of health risk assessment. In this work, an untargeted approach is proposed for the evaluation of the exposure to volatile organic compounds of workers in an engine manufacturing plant by GC–MS measurements, coupled with solid-phase microextraction (SPME). The analytical procedure was optimized in terms of SPME fiber, adsorption time, desorption time, and temperature gradient of the chromatographic run. For the microextraction of VOCs, the SPME fibers were exposed to the air in two different zones of the manufacturing factory, i.e., in the mixing painting chamber and the engine painting area. Moreover, the sampling was carried out with the painting system active and running (system on) and with the painting system switched off (system off). Overall, 212 compounds were identified, but only 17 were always present in both zones (mixing painting chamber and engine painting area), regardless of system conditions (on or off). Finally, a semi-quantitative evaluation was performed considering the peak area value of the potentially most toxic compounds by multivariate data analyses. [ABSTRACT FROM AUTHOR]

In this study, the levels of polycyclic aromatic hydrocarbons (PAHs) and their carcinogenic health risks were investigated in four commonly consumed smoked fish species (Trichogaster fasciata, Chanda nama, Pethia manipurensis, and Mystus ngasep) from North-eastern part of India. Gas chromatography-mass spectrometry (GC-MS) was utilized for the separation and analysis of PAH compounds. The study revealed that concentrations of major PAHs in the investigated fish were Pyrene, Fluoranthene, Benzo(b)Fluoranthene, Chrysene, Benzo(a)anthracene, Anthracene, and Fluorene, respectively. The concentrations of these PAHs in fish samples were well below the maximum permissible level of 2.0 µg/kg for BaP, as recommended by the European Union (EU) under regulation No 835/2011. The highest recorded sum of four PAHs (BaP + Chry + BbF + BaA) was found in P. manipurensis (0.185 µg/kg), followed by T. fasciata (0.128 µg/kg), and C. nama (0.073 µg/kg). The four PAHs were not detected in M. ngasep. Importantly, sum of these four PAHs in all fish species remained well below the maximum permissible level of 12 µg/kg for BaP in smoked fish intended for human consumption, as specified by EU regulation 835/2011. Furthermore, ratio of low molecular weight (LMW) PAHs to high molecular weight (HMW) PAHs in all fish samples was found to be less than 1. This suggests that PAHs in fish samples primarily originated from pyrogenic sources, such as combustion processes, rather than petrogenic sources. The estimated daily intake of carcinogenic PAHs, expressed as Benzo(a)pyrene equivalent dose, ranged from 2.27 × 10−9 to 6.15 × 10−9 mg/kg/day. The calculated excess carcinogenic risk values varied from 1.66 × 10−8 to 4.49 × 10−8, all of which were below the permissible level (1.0 × 10−5) set by USEPA for causing cancer risk. Consequently, this study suggests that consumption of these smoked fish species does not pose significant carcinogenic health risks to consumers. [ABSTRACT FROM AUTHOR]

Strawberry aroma, crucial for determining quality, involves complex volatile compounds which are challenging to identify. This study explores strawberry aroma analysis using Gas Chromatography-Mass Spectrometry (GC-MS) and the Automated Mass Spectral Deconvolution and Identification System (AMDIS). Central to our research is the creation of a bespoke strawberry Volatile Organic Compounds (VOCs) user library using AMDIS, specifically for analyzing strawberry aromas. The library contains VOCs from 61 strawberry cultivars, integrating information on 104 VOCs, including mass spectra, retention index, chemical class, CAS number, formula, odor threshold, and odor description. This custom library significantly outperformed a commercial library by reducing potential false hits by 200, decreasing the size of report files by over 96%, and, most importantly, shortening AMDIS analysis processing time from 31 s to 9 s, representing an approximate 71% reduction. Further, the study demonstrates the library's practical application by contrasting the aroma profiles of strawberries harvested in winter and spring. This comparison revealed significant VOC variations depending on seasonal temperature changes, offering insights into environmental influences on strawberry aroma. In conclusion, this research marks a significant advance in strawberry aroma quality analysis. The strawberry VOC library developed in this study is expected to greatly aid targeted metabolomics and flavor research in strawberry breeding. [ABSTRACT FROM AUTHOR]

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Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

AbstractGamma irradiation is one of the preservation techniques used to increase the shelf life of foods. The current study was aimed to determine the volatile flavor contents of melon (Cucumis melo L.) seeds and the impact of gamma radiation upon these compounds. The seeds were irradiated with gamma rays at 1, 5, 10, and 20 kGy doses. The volatile compounds were extracted by simultaneous distillation extraction (SDE), using n-pentane/diethyl ether (1:1, v/v) and determined by gas chromatography-mass spectrometry (GC-MS). A total of 70 volatile flavor compounds were identified in the control, with 2,3-butanediole (18.01%) and 1-hexanol (6.06%) as the major compounds. The number and percentage of the volatile compounds varied with the gamma irradiation doses. Twenty-eight volatile compounds were present in the non-irradiated and irradiated samples at different concentrations. Up to the recommended gamma irradiation dose of 10 kGy, the number of volatile flavor compounds generally increased. There were changes in both the number and percentages of the identified volatile flavor compounds following gamma irradiation of the Cucumis melo L seeds. [ABSTRACT FROM AUTHOR]

Phthalates (PAEs) are a class of organic pollutants that are continuously released and present in the environment and are listed as priority-controlled pollutants. Soil is one of the main final fates of PAEs in the environment, and China has fully launched investigations and controls on soil pollution of PAEs. Analysis is the foundation of environmental monitoring and scientific research, and the certified reference materials in soil are important means to ensure the accuracy and reliability of determination for soil. However, the existing relevant reference materials do not meet the actual needs of pollution monitoring in China. In this study, according to the characteristics of PAEs pollution and quality control requirements of actual samples, four certified reference materials for PAEs analysis in soils have been developed through the nine laboratories’ collaborative analysis. The candidates were mainly collected from agricultural soils, plastic film mulched soil, industrial soil, and plastic recycling station soil. After homogeneity and stability testing, the results show that both homogeneity and stability meet the requirements. During the certification process, in response to the difficulty of controlling the PAEs analysis blank, the pollution source of the blank was identified and confirmed, and strict quality control measures were formulated to ensure that the blank concentration throughout the entire process remained stable within a certain range. Nine laboratories used gas chromatography-mass spectrometry (GC-MS) to collaboratively determine the values of 4 PAEs and evaluated their uncertainty in soils. The certified values of 4 PAEs in soils ranging from 36µg/kg to 2.87mg/kg. The authoritative domestic laboratory used isotope dilution mass spectrometry to verify the accuracy of the certification results. This series of reference materials have been approved as a national first-class reference material, numbered from GBW07595 to GBW07598, which meets the requirements of PAEs analysis quality assurance and quality control, and provides technical support for ecological geological survey and evaluation. [ABSTRACT FROM AUTHOR]

A method of gas chromatography-mass spectrometry (GC-MS) was established to determine the migration of dibutyl sebacate, dioctyl sebacate, diisooctyl sebacate, decanedioic acid bis (2,2,6,6-tetramethyl-4-piperidinyl)ester in water-based, acidic and alcoholic food simulants, and olive oil and chemical alternative solvents. The 95% ethanol and isooctane chemical substitution solutions were directly analyzed by GC-MS. The olive oil samples were extracted with acetonitrile followed by QuEChERS purification, and then analyzed by GC-MS. Other simulants (water, 4% acetic acid, 10% ethanol, 20% ethanol, and 50% ethanol) were extracted with n-hexane and then determined by GC-MS. The results showed that the method is well performed under optimized conditions, with the correlation coefficient (r²) greater than 0.995. The limits of detection and the limits of quantitation of the four sebacic acid ester compounds in water, 4% acetic acid, 10% ethanol, 20% ethanol, 50% ethanol, 95% ethanol, isooctane, and olive oil simulants are 0.1-0.2 mg/kg, 0.3- 0.5 mg/kg, respectively. Migration experiments on plastic samples were conducted, and spiking experiments at three concentration levels of 0.30, 2.0, 4.0 mg/kg in water, 4% acetic acid, 10% ethanol, 20% ethanol, 50% ethanol, 95% ethanol, and isooctane food simulants, and three concentration levels of 0.50, 2.0, 4.0 mg/kg in olive oil food simulants were carried out. The spiking recoveries range from 92.5% to 108%, and the relative standard deviations (RSDs) are 2.4%-8.8%. The method solves the problem that decanedioic acid bis (2,2,6,6-tetramethyl-4-piperidinyl) ester cannot be extracted into n-hexane in 4% acetic acid by adjusting pH value using ammonium hydroxide, the optimal pH range was determined by comparing the responses of four targets at different pH values. QuEChERS was firstly used for migration experiments of sebacic acid esters in food contact materials to solve the turbidity and partial oil precipitation of olive oil simulants in the concentration process after extraction. By optimizing the QuEChERS filling material, the interference of organic acids, fatty acids, sugar and other impurities on the targets were reduced, producing greater separation effect of the targets. The separation efficiency of four chromatographic columns with different polarity was compared, and the DB-17HT column was selected to detect the four sebacic acid esters simultaneously. Plastics such as polypropylene, polyethylene terephthalic acid terephthalate, polyvinyl chloride, composite membranes, paper cups, recycled PET and recycled PVC were collected and migration experiments were carried out, the migration of sebacic acid esters in these plastics materials was investigated. This method is highly sensitive, precise, and accurate, fully meeting the requirement for determining the migration of the sebacic acid esters in food contact materials and their products. [ABSTRACT FROM AUTHOR]

Five kinds of commercially available sour fish sauce were taken as the research object to clarify their quality and flavor characteristics. The physicochemical and nutritional indexes, free amino acids, and volatile components were analyzed. The results showed that the moisture, ash, total acid, amino acid nitrogen, reducing sugar, protein, vitamin C and fat contents in the five kinds of sour fish sauce were significantly different (P<0.05). In total, 17 free amino acids were detected, including 7 essential amino acids and 10 non-essential amino acids. The content of total free amino acids in the samples ranged from 7.954-14.998 mg/g. The total content of free amino acids in sample Z was the highest at 14.998 mg/g. The content of umami glutamic acid was the highest in the L sample, which was 4.689 mg/g, and the taste activity value (TAV) reached 15.63, which was much higher than that of other samples. The electronic nose results showed that the main volatile components of five kinds of sour fish sauce were nitrogen oxides, short-chain alkanes, inorganic sulfur compounds, alcohol ether aldehydes, and organic sulfides. Principal component analysis could differentiate between different sour fish sauces. In this study, 57 volatile components were detected in five kinds of sour fish sauce using gas chromatography-mass spectrometry (GC-MS), including 20 esters, 14 alcohols, 14 alkenes, 2 acids, 2 phenols, 3 aldehydes and 2 ketones. Using orthogonal least squares-discriminant analysis (OPLS-DA) and variable important projection (VIP) selection, eighteen key volatile aroma compounds, including zingalene, ethanol, ethyl cetanoate, ethyl linoleate, limonene, acetic acid, linalool, ethyl myristate, 4-ethyl-2-methoxyphenol, phenethyl alcohol, alpha-curcumene, methyl salicylate, β-sesquiphellandrene, citral, isoamyl alcohol, camphene, β-bisabolene and geraniol, were identified in the five kinds of sour fish sauce. In conclusion, the results provide a basis for the quality evaluation and comprehensive development of sour fish sauce. [ABSTRACT FROM AUTHOR]

To clarify the volatile organic compounds in the essential oil of Citri grandis exocarpium, explore the key aroma components of the essential oil and establish the associated quality control standards, vapour distillation was used to extract the essential oil of Citri grandis exocarpium. Sensory evaluation, combined with electronic nose, gas chromatography-mass spectrometry (GC-MS) and gas chromatography-mass spectrometry (GC-MS/O) analyses, was performed to clarify the key aroma components in Citri grandis exocarpium while assessing the pesticide residues. The results revealed that the main representative volatile flavors of Citri grandis exocarpium were found to be citrusy, sweet, medicinal, woody, and pungent, as determined via sensory evaluation. A total of 68 volatile organic compounds (VOCs) were detected in the essential oil of Citri grandis exocarpium by GC-MS, among which, the main VOCs, olefins, alcohols, and esters, accounted for 84.48%, 6.67%, and 6.05% of the total, respectively, with limonene, lauroylene and γ-pineole as the main VOCs. In combination with GC-MS/O, 15 key volatile characteristic aroma components were confirmed. In combination with the analysis of pesticide residues, it was clarified that the organochlorine pesticide residues in Citri grandis exocarpium essential oil under hydrodistillation extraction conformed to the standards specified in the Pharmacopoeia. The present study clearly elucidated the volatile organic composition and quality safety of the essential oil from Citri grandis exocarpium, which provides a reference for Citri grandis exocarpium product development and quality control. [ABSTRACT FROM AUTHOR]

To investigate the effect of drying methods on the volatile flavor substances of Toona sinensis, the volatile components of vacuum freeze-dried, heat pump-dried, hot air-dried, and microwave vacuum-dried Toona sinensis samples were analyzed by gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS) coupled with relative odor activity values, and the differences of volatile components among samples were further explored by combining the stoichiometric principal component analysis and partial least square discriminant analysis. The results showed that 78 peaks were detected and 59 compounds were identified by GC-IMS. 94 kinds of volatile compounds were identified by GC-MS, and the main volatile components were sulfides, olefins and aldehydes. The content of total volatile compounds was significantly reduced after drying. The key aroma compounds in Toona sinensis samples were identified by ROAV method, such as (E,Z)-di-1-propenyldisulfide, 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene, hexanal, 2-hexenal and eugenol. The PCA and PLS-DA results showed that the samples with different drying methods were not only clearly separated from the raw samples, but also significantly different from each other. The raw samples and vacuum freeze-dried samples were grouped, and the other three dried Toona sinensis samples were grouped. According to the variable importance in projection score, a total of 10 (VIP>1) labeled volatile compounds were selected. The drying method had significant effect on the flavor characteristics of Toona sinensis, and the vacuum freeze-dried group was the closest to the raw sample, while heat pump-drying was the most suitable dehydration method for Toona sinensis, considering the practical application. This study provides some theoretical references for flavor quality control in the thermal processing process.

AbstractThe cytotoxic activities of apolar extract of Lactarius salmonicolor and its fractions and subfractions were screened against colon (CaCo-2), prostate (LNCaP), lung (H1299), and breast (MCF-7) cancerous cell lines. The main extract of Lactarius salmonicolor that was cytotoxic to CaCo-2 (EC50: 137.1 ± 2.7 µg/mL) and LNCap (EC50: 131.2 ± 2.6 µg/mL) mainly contains fatty acids (99.9%). To characterize the cytotoxic activity, it was fractionated by a silica gel column. Two cytotoxic fractions were re-fractionated to obtain subfractions. The extract, four cytotoxic fractions, and all subfractions were analyzed by gas chromatography-mass spectrometry (GC-MS). The GC-MS data and the cytotoxic activity (EC50) results were classified using principal component analyses (PCA). According to PCA, the cytotoxic fractions containing abundant benzoic acid (0.01%–0.35%), cinnamic acid (0.01%–0.36%), azelaic acid (0.01%–0.92%), 2,4-decadienal (0.01%–0.12%), (Z)-9-palmitoleic acid (0.01%–1.09%), 18-hydroxy 2,4-diene oleic acid (0.01%–26.71%), arachidic acid (0.01%–6.70%), desmosterol (0.01%–12.27%), and steroids (0.01%–9.51%) were clustered. LSP.9-10, which causes another cluster, is caused by 8,11,14- eicosatrienoic acid, 11,14,17-eicosatrienoic acid, 9(Z)-decenoic acid compounds, and saturated fatty acids with 10 and 16 carbons. Hence, these compounds may be responsible for the cytotoxic activity. This study demonstrates that GC-MS and chemometric analysis can identify the components responsible for biological activity in combination with biological activity data. [ABSTRACT FROM AUTHOR]

The pheomelanin precursor 5-S-cysteinyldopa (5SCD) exhibits promising potential as a urinary and serum biomarker for melanoma. Nonetheless, it is important to note that 68.8% of early-stage melanoma cases remained undetected when employing 5SCD as a biomarker, underscoring the inadequacy of its efficacy, especially in identifying stage I/II melanoma. In lieu of detecting free 5SCD, the hydrolysis products of pheomelanin, namely, 4-amino-3-hydroxyphenylalanine (4-AHP) and 3-amino-4-hydroxyphenylalanine (3-AHP) offer the prospect of achieving heightened sensitivity and broader scope in early-stage melanoma diagnosis through direct chemical processes. This study introduces an innovative gas chromatography-mass spectrometry (GC-MS) methodology to identify early-stage melanoma by comparing the concentrations of AHPs across 80 stage I/II melanoma patients against 32 healthy controls. The approach demonstrated linear response within the 0.5–20 μg/mL range for reference AHPs detection. The urine levels of AHPs were 1.3 ± 0.5 μg/mL in the control/volunteer group (n = 32), 8.1 ± 1.6 μg/mL in stage I and II melanoma patients (n = 28), and 6.3 ± 1.9 μg/mL in stage II melanoma patients (n = 52). The findings unequivocally underscore the diagnostic promise of AHPs as a robust tool for early-stage melanoma assessment in laboratory medicine. [ABSTRACT FROM AUTHOR]

To investigate the effect of drying methods on the volatile flavor substances of Toona sinensis, the volatile components of vacuum freeze-dried, heat pump-dried, hot air-dried, and microwave vacuum-dried Toona sinensis samples were analyzed by gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS) coupled with relative odor activity values, and the differences of volatile components among samples were further explored by combining the stoichiometric principal component analysis and partial least square discriminant analysis. The results showed that 78 peaks were detected and 59 compounds were identified by GC-IMS. 94 kinds of volatile compounds were identified by GC-MS, and the main volatile components were sulfides, olefins and aldehydes. The content of total volatile compounds was significantly reduced after drying. The key aroma compounds in Toona .sinensis samples were identified by ROAV method, such as (E,Z)-di-1-propenyldisulfide, 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene, hexanal, 2-hexenal and eugenol. The PCA and PLS-DA results showed that the samples with different drying methods were not only clearly separated from the raw samples, but also significantly different from each other. The raw samples and vacuum freeze-dried samples were grouped, and the other three dried Toona .sinensis samples were grouped. According to the variable importance in projection score, a total of 10 (VIP>1) labeled volatile compounds were selected. The drying method had significant effect on the flavor characteristics of Toona sinensis, and the vacuum freeze-dried group was the closest to the raw sample, while heat pump-drying was the most suitable dehydration method for Toona sinensis, considering the practical application. This study provides some theoretical references for flavor quality control in the thermal processing process. [ABSTRACT FROM AUTHOR]

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Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tobacco leaves need to aged under certain temperatures and humidity for 1 to 3 years. Natural aging, also called fermentation, is a slow process. This article explores the correlation between microorganisms on the surface of flue-cured tobacco and key flavor substances during this process. High-throughput sequencing was used to characterize the composition of bacterial and fungal communities on the surface of flue-cured tobacco from Hunan, Liaoning, Guizhou, Shandong, Yunnan, Fujian, Brazil, and Zimbabwe. Gas chromatography—mass spectrometry (GC-MS) was employed to determine the flavor substances in flue-cured tobacco and correlation analysis between microbial diversity and flavor substances was performed. The function and abundance of key enzymes involved in the degradation of macromolecules on the surface of flue-cured tobacco were predicted using PICRUSt and FUNGuild. Different flavor styles of flue-cured tobacco possessed different flora structures, and the abundance of the genus Bacillus was high and significantly positively correlated with the content of the main flavor substances—carotenoid and cembranoid degradation products (p < 0.05). The content of the Enterobacter genus was higher in light-flavor style flue-cured tobacco and significantly negatively correlated with the above substances (p < 0.05). Among the fungal genera, Wallemia exhibited a significantly positive correlation with phenylacetic acid, palmitic acid, and α-ionol (p < 0.05). The abundance of the macromolecule-degrading enzymes in the bacterial community was generally higher than in the fungal community, especially the enzymes that hydrolyzed, transferred, and isomerized starch, protein, and cellulose. Classifying the tobacco leaves according to the flavor style revealed that the expression levels of a series of enzymes acting on pectin hydrolysis and cleavage and laccase were higher in strong-flavor flue-cured tobacco. This study explored the microorganisms related to the key substances of flue-cured tobacco and provided a theoretical basis for using microorganisms to improve the flavor. [ABSTRACT FROM AUTHOR]