Search Results (694)

Background/Objectives: Volatile organic compounds (VOCs) have emerged as promising non-invasive biomarkers for assessing metabolic and reproductive health. In the context of assisted reproductive techniques (ARTs), the volatilomic composition of follicular fluid (FF) may reflect the biochemical environment surrounding the oocyte, influencing fertilization success and embryo development. This study aimed to characterize the volatilomic profile of FF in women undergoing ARTs and to explore associations between specific VOCs and female fertilization-related parameters (FFRPs). Methods: A total of 54 Caucasian women aged 19–39 years, enrolled between October 2015 and July 2019, were recruited at the Assisted Reproduction Laboratory of the Local Health Unit of Cova da Beira, Covilhã. FF samples were analyzed via gas chromatography–mass spectrometry (GC–MS) in scan mode, identifying 136 VOCs, of which 72 were selected based on prevalence. Sixteen FFRPs were evaluated, including age, body mass index (BMI), smoking habits, infertility factor, oocyte yield, embryo quality, β-hCG levels, country of birth, and reproductive history. Associations between VOCs and FFRPs were assessed using the Chi-square (χ²) test. Results: Significant correlations (p ≤ 0.05) were identified between 45 VOCs and 11 FFRPs. The detected compounds comprised alkanes, siloxanes, aromatics, alcohols, ketones, aldehydes, carboxylic acids and esters, fatty acid derivatives, epoxides, acrylates, nitriles, and sterols. Several VOCs were associated with more than one FFRP, indicating overlapping metabolic pathways that may influence reproductive performance. Conclusions: The volatilomic profile of FF demonstrates significant variability linked to individual reproductive and metabolic factors. VOC analysis may provide novel insights into follicular physiology, representing a promising approach for identifying potential biomarkers of infertility and ART outcomes. Full article

The red imported fire ant, Solenopsis invicta Buren, is a eusocial insect that relies on a sophisticated chemical communication system for colony organization and function. Its olfactory system is vital for detecting semiochemicals in the environment. This study utilized single sensillum recording (SSR) to assess the olfactory neuronal responses of female alates and workers from basiconica sensilla exposed to a panel of 62 individual pheromones and general odorants, including terpenes, terpenoids, pyrazines, pyridines, ketones, aldehydes, alcohols, acids, aliphatic and aromatic acetates, benzoates, benzyl esters, and three essential oils. Basiconica sensilla, which contain multiple olfactory receptor neurons (ORNs), exhibited moderate to strong responses to most of the tested compounds, demonstrating a broad sensitivity to all odorants elevated. Comparative analysis of the two castes revealed that ORNs had similar responses to 47 odorants; however, workers showed stronger responses to nine specific compounds, while female alates responded more strongly to six others. These differences underscore the caste-specific olfactory tuning, likely reflecting their distinct roles within the colony. This study presents the first comprehensive mapping of basiconica sensilla responses to general odorants in S. invicta female alates and workers, enhancing our understanding of the S. invicta chemical ecology and potentially contribute to more effective fire ant management strategies. Full article

Effectively separating and utilizing macerals based on their properties is crucial for the efficient and high-value utilization of coal. This study enhances the traditional screening method by employing primary and stepwise crushing techniques to separate Yili coal (YLC) into inertinite-rich (YLI) and vitrinite-rich (YLV) concentrates. The structural characteristics and direct coal liquefaction (DCL) performance of YLC, YLV and YLI are subsequently studied. The results indicate that YLV exhibits the highest yield of oil, asphaltene and gas, a finding closely linked to its elevated content of highly active functional groups and its long aliphatic and bridge chains. Furthermore, the liquefaction oil from YLV contains the highest content of alkanes and phenols, which is attributed to its high content of aliphatic hydrocarbons and phenolic hydroxyl groups. In contrast, YLI exhibits the lowest product yield relative to YLC and YLV, with the highest contents of aromatics, esters, and ketones in its oil, due to its high contents of aromatic and carbonyl carbon. The separation, structural characteristics and DCL studies of macerals from Yili coal offer valuable insights for the efficient separation and utilization of macerals. Full article

Ketones are metabolites primarily produced by the liver and are utilized by various organs outside of the liver. Recent advances have demonstrated that ketones serve not only as alternative energy sources but also as signaling molecules. Research indicates that ketones can influence cancer development and metastasis, cardiac metabolic and structural remodeling, physical performance, vascular function, inflammation, and the aging process. Emerging evidence from preclinical and early-phase clinical studies suggests that strategies such as ketone salts, ketone esters, and the ketogenic diet may offer therapeutic benefits for conditions like heart failure, acute cardiac injury, diabetic cardiomyopathy, vascular complications, atherosclerosis, hypertension, and aortic aneurysm. This literature review updates the current understanding of ketone metabolism and its contributions to cardiovascular health and diseases. We highlight the underlying molecular mechanism with post-translational modification known as β-hydroxybutyrylation, which affects the fate and function of target proteins. Additionally, we discuss the therapeutic challenges associated with ketone therapy, the potential of using ketone levels as biomarkers for cardiovascular diseases, as well as gender- and age-specific differences in ketone treatment. Finally, we explore future research directions and what is needed to translate these new insights into cardiovascular medicine. Full article

The quality of different coffee varieties varies, and the corresponding bioactive value of coffee processing byproducts is often overlooked. For that, we employed HPLC, GC-MS, and electronic sensory analyses to evaluate the key bioactive components, antioxidant potential, and flavor traits of green coffee bean and coffee processing byproducts of seven coffee varieties. The results showed that green coffee beans (Oe+Ie) and exocarp (Ep) possessed strong antioxidant activity and high total phenolic content (TPC), caffeine and trigonelline content. Among the varieties, DR390 contained higher levels of total phenols, caffeine, and trigonelline, whereas DR402 was rich in caffeine and chlorogenic acid. In addition, RY3 exhibited higher TPC, total flavonoid content (TFC), caffeine, and chlorogenic acid. The parchment (Pc) layer was rich in soluble sugars (1.83–5.43%), while the silverskin (Sk) contained relatively high levels of chlorogenic acid (3.58–4.69 mg/g). Flavor analysis identified eleven classes of volatile compounds in green coffee bean (Oe+Ie) and byproducts (Ep, Pc, Sk), with esters, ketones, alcohols, and aldehydes being the most prevalent. Seven key aroma compounds, including methyl salicylate, phenethyl alcohol, nonanal, and benzaldehyde, were identified across the various structural tissues of coffee fruit. Distinct flavor profiles were observed among the coffee fruit parts: green coffee bean (Oe+Ie) was nutty; the Ep showed fruity and cocoa-like aromas; the Pc and Sk exhibited papery and nutty aromas, respectively. Varieties DR397, DR402, and RY3 exhibited pronounced aroma profiles. Comprehensive analysis showed that DR402 and RY3 had higher overall scores for bioactive and flavor components than other varieties in their groups. In summary, green coffee bean (Oe+Ie) exhibited strong antioxidant activity and high levels of bioactive compounds. Coffee byproducts, such as the Ep, hold potential for extracting natural antioxidants and bioactive compounds to develop specialty products or for other high-value utilization. Full article

Kargı Tulum cheese differs from other Tulum cheeses with its unique production and ripening method. No systematic study has yet explored the change in the volatile compounds and fatty acids during the ripening process of Kargı Tulum cheese. The objective of this study was to monitor the change in the fatty acids and volatile compounds of Kargı Tulum cheese at different time points during the production and ripening stages. Fatty acid profile, lipid quality parameters and volatile compound profiles were determined. A principal component analysis (PCA) was performed to determine how the volatile profiles differed across production and ripening stages. During the ripening, short- and medium-chain fatty acids (FAs) increased with notably high levels of butyric acid. Lipid quality parameters, including total saturated FAs (SFAs), atherogenicity index (AI), and thrombogenicity index (TI), remained unchanged throughout ripening. A total of 62 volatile compounds (VOC) were detected. Esters and ketones were the most abundant groups in fresh curds, while carboxylic acids became the dominant group by the end of the ripening process. The total concentration of most VOC increased over time. Butyric acid, hexanoic acid, ethyl hexanoate and acetic acid were the dominant compounds contributing the flavor of the Kargı Tulum cheese. This study presents data on what flavor compounds form and how they change during ripening and can be useful for comparative purposes in future studies on ripened raw milk cheeses. Full article

This study investigated the effect of superheated steam (SS) assisted glycosylation modification on the flavor profile of oyster peptides (OP), and explored the correlation between key flavor compounds and glycosylation degree using Gas Chromatography–Ion Mobility Spectrometry (GC-IMS) and nano-scale Liquid Chromatography coupled with High-Resolution Mass Spectrometry (nano-LC/HRMS). The results indicated that SS treatment accelerated the glycosylation process, reduced free amino groups level, and distinguished their unique flavor through E-nose. GC-IMS analysis detected 64 signal peaks including 13 aldehydes, 6 ketones, 7 esters, 6 alcohols, 2 acids, 2 furans and 5 other substances. And it was revealed that SS-mediated glycosylation treatment reduced the levels of fishy odorants like Heptanal and Nonanal, while promoting the pleasant-smelling alcohols and esters. In addition, Pearson correlation showed a positive correlation between excessive glycation and the increase in aldehydes, which might cause the recurrence of undesirable fishy notes. Further nano-LC/HRMS analysis revealed that arginine and lysine acted as the main sites for glycosylation modification. Notably, glycosylated peptides such as KAFGHENEALVRK, DSRAATSPGELGVTIEGPKE, generated by mild SS treatment could convert into ketones and pyrazines in subsequent reactions, thereby contributing to overall sensory enhancement. In conclusion, SS treatment at 110 °C for 1 min significantly improved the flavor quality of OP and sustains improvement in subsequent stages, providing theoretical support for flavor optimization of oyster peptides. Full article

Comprehensive characterization of the mango peel volatilome is essential to revealing its aromatic potential and enabling its revalorization as a natural flavoring. The volatile profile of Mangifera indica L. var. Osteen peels at three ripening stages (green, ripe, overripe) was analyzed before and after thermal drying (45 °C, 18 h): an unavoidable stabilization step for valorization applications. HS–SPME/GC–MS enabled the identification of 76 volatile compounds across different key aroma-contributing families: monoterpenes, sesquiterpenes, alcohols, aldehydes, ketones, esters, furanics and norisoprenoids. The ripening stage significantly influenced the qualitative and quantitative volatilome in fresh samples but drying heavily reduced those differences. Multivariate analyses confirmed that the drying process is the dominant factor shaping the stabilized peels’ volatilome. These findings underscore the industrial relevance of this side-stream: regardless of ripening stage, mango peels can be uniformly stabilized to be upcycled into aroma-rich ingredients. It simplifies raw material sourcing and supports food waste revalorization strategies in flavor and fragrance developments. Full article

Pile fermentation is a crucial process for developing the characteristic mellow taste and aged aroma of dark tea, yet the internal quality transformation mechanism of this process is still unclear. This study employed a high-sensitivity analytical platform based on gas chromatography–mass spectrometry (GC-MS) to systematically investigate the dynamic interplay between key chemical components, enzyme activities, and volatile compounds during the pile fermentation of primary dark tea. Our findings revealed a significant decrease in ester-type catechins, crude protein, and protopectin, alongside a notable accumulation of non-ester-type catechins, gallic acid, and soluble components. The multi-enzyme system—comprising PPO/POD, pectinase/cellulase, and protease—cooperatively drove the oxidation of phenols, cell wall degradation, and the release of aromatic precursors. This was complemented by GC-MS analysis, which identified and quantified 103 volatile compounds across nine chemical classes. The total content of volatile compounds increased significantly, with alcohols, esters, and aldehydes/ketones being the dominant groups. Floral and fruity compounds such as linalool and geraniol accumulated continuously, while esters exhibited an initial increase followed by a decrease. Notably, carotenoid degradation products, including β-ionone, were significantly enriched during the later stages. This study revealed a “oxidation–hydrolysis–reconstruction” metabolic mechanism co-driven by microbial activity and a multi-enzyme system, providing a theoretical foundation for the precise regulation of pile fermentation and targeted quality improvement of primary dark tea. Full article

Humulus lupulus L. (hops) is essential in brewing due to its contributions to bitterness, flavor, and aroma. This study compared the volatile profiles of five commercially important hop varieties—Amarillo, Ariana, Cascade, Centennial, and El Dorado—grown in their main regions of origin (United States for Amarillo, Cascade, and El Dorado; Germany for Ariana; and Brazil for Centennial). Headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC-MS) enabled the identification of 312 volatile compounds, including monoterpenes (e.g., myrcene, linalool, geraniol), sesquiterpenes (e.g., humulene, caryophyllene), esters, alcohols, aldehydes, and ketones. Amarillo showed the highest myrcene content (22.61% of the total volatile area), while Centennial was distinguished by elevated γ-muurolene (20.59%), and El Dorado by the highest level of undecan-2-one (10.47%), highlighting marked varietal differences in key aroma-active constituents. Multivariate, including principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), clearly discriminated the five varieties: PC1 (41.04% of the variance) separated samples enriched in fruity/floral monoterpenes and esters from those dominated by woody/resinous sesquiterpenes, whereas PC2 (25.93% of the variance) reflected variation in medium-chain esters, ketones, and waxy compounds. These chemometric patterns demonstrate that both genetic background and growing region terroir strongly shape hop volatile composition and, consequently, aroma potential, providing brewers with objective criteria for selecting hop varieties to achieve specific sensory profiles in beer. Full article

The flavor and aroma of kiwifruit are largely influenced by the concentration of Volatile Organic Compounds (VOCs). To analyze the volatile profiles and identify characteristic aroma compounds, this study utilized Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) to analyze the aromatic compounds sourced from seven major production regions in China and New Zealand, covering red-, green-, and yellow-fleshed varieties. A total of 77 VOCs were identified, with esters, aldehydes, and ketones as the dominant classes. Significant regional and varietal differences were observed: red-fleshed kiwifruits from Yunnan exhibited high levels of 2-Vinyl-5-methylfuran, Ethyl formate, and 1-Penten-3-one; green-fleshed fruits from Shaanxi were rich in Limonene and Methyl hexanoate, and those from Yunnan were rich in 1-Propanol and 1-Hexanol; and yellow-fleshed fruits from Henan were characterized by Methyl salicylate and 3-Hydroxy-2-butanone. Orthogonal partial least squares discriminant analysis (OPLS-DA) successfully classified kiwifruits by origin and variety, confirming the stability and predictive power of the model (Q2Y > 0.97). This study also elucidated the key metabolic pathways—including lipid oxidation, amino acid degradation, and terpenoid metabolism—underlying the formation of these characteristic VOCs. These findings provide a theoretical foundation for the biochemical regulation of kiwifruit flavor and support the development of origin-tracing and quality-assessment tools based on VOC fingerprints. Full article

This study aimed to characterize the physicochemical, structural, and volatile compound changes in commercially sterilized pre-cooked braised chicken (PBC) during storage at 25 °C, using analyses conducted every 30 days from 30 to 180 days. Assessed parameters included microstructure, color, texture, pH, malondialdehyde (MDA) content, Ca²⁺-ATPase activity, and volatile organic compounds (VOCs). Significant quality changes occurred during storage. Specifically, the L* value decreased, and the a* value increased, while hardness, springiness, chewiness, and Ca²⁺-ATPase activity declined. pH increased from 6.01 to 6.59, and MDA content rose from 10.16 to 23.42 nmol/g. 91 VOCs were identified by gas chromatography-ion mobility spectrometry (GC-IMS), comprising 13 alcohols, 18 aldehydes, 18 ketones, 3 acids, 9 esters, 12 hydrocarbons, 6 aromatics, and 12 others. VOC profiles shifted dynamically: key aldehydes and ketones decreased initially, then increased, whereas alcohols, esters, hydrocarbons, and sulfur-containing compounds increased, then decreased. Prolonged storage significantly deteriorated the quality and altered the flavor profile, providing insights for PBC storage. Full article

Human milk is the benchmark for formulating infant formula, the latter serving as a substitute when breastfeeding is not possible. Nevertheless, the lipid composition and structure of commercially available infant formulas still differ from those of human milk fat. Accordingly, this paper employs a computational–experimental framework to optimize formulations of prepared lipid (PF). The quality of the optimized product was further validated by analyzing volatile organic compounds (VOCs), color, lipid oxidation indicators, and oxidative stability. The results show that a total of 43 fatty acids (FA) were detected in the base oil, and palmitic acid, oleic acid, and linoleic acid are the main types of FA. Through computer simulation, 6 of PF were obtained, which are superior to commercial products (SP) in the similarity score of the parsimonious model, and PF1 has the highest score (84.15). Multivariate statistical analysis indicates that PF may be more suitable for use in infant formula milk powder due to its lipid composition. Gas chromatography-ion mobility spectrometry was used to study the VOCs content of PF and SP, and a total of 35 VOCs were identified. It was found that alcohols and ketones accounted for the highest proportion in PF, while Nitriles, Aldehydes, and Esters were the most abundant in SP. In the comparison of the basic physical and chemical indices between PF and SP, the peroxide value and p-anisidine value of PF are lower, and the overall oxidation stability is stronger than that of SP. This study provides a reference for the preparation and multi-dimensional evaluation of human milk fat substitutes. Full article

This paper investigated the effects of agroforestry (AF) on the sensory profiles of cocoa beans and the organoleptic quality of end-chocolates. A three-day opening delay for the Ivorian hybrid cultivar commonly known as “Mercedes” (Amelonado × West African Trinitario) from AF and full-sun (FS) plantations as control located at five cocoa-producing areas were fermented in wooden boxes for 6 days and stirred at days 2 and 4. Fermented cocoa was sun-dried until reaching 7–8% moisture and processed into chocolate. Volatile compounds of cocoa powder and chocolate were analyzed using the SPME-GC-MS method, while the organoleptic perception of chocolates was assessed by 12 professional judges according to 10 sensory descriptors. The findings revealed that the concentrations of esters ranged from 9.41 ± 0.61 to 19.35 ± 1.28 µg.g⁻¹, aldehydes from 11.56 ± 0.7 to 25.33 ± 1.5 µg.g⁻¹, and ketones from 5.76 ± 0.62 to 55.84 ± 4.39 µg.g⁻¹ in cocoa beans regardless of the cropping system. However, the concentrations of some volatile compounds classes including alcohols, acids, and pyrazines were similar in AF and FS chocolate samples. AF system clearly influenced the volatile compound profiles of cocoa beans in only the Adzopé, Guibéroua, and Méagui regions without impacting those of the chocolates regardless of the geographical origin after fermentation and roasting. Furthermore, AF chocolate was not less appealing than the FS chocolate samples. So, AF system did not significantly influence the sensory perception of chocolate. AF can therefore be encouraged as a cropping system for cocoa cultivation to reduce deforestation and promote reforestation, ensuring the sustainability of cocoa. Full article

Fermented tea beverage (FTB) has garnered significant attention owing to its unique combination of tea and wine flavors and its potential health benefits. This study investigates FTB co-fermented using different inoculum sizes of L. plantarum HYY-S10 and P. pastoris, evaluating physicochemical properties during the fermentation process. The final FTB products were comprehensively evaluated for their antioxidant activity, organic acid content, sensory characteristics, volatile flavor compounds, and microbial diversity. Compared with natural fermentation, the 1:1 mixed fermentation of these two microorganisms enhanced the antioxidant capacity and organic acid content of FTB. Furthermore, sensory evaluation revealed higher overall acceptability. Analysis of volatile compounds demonstrated an increase in the production of alcohols, esters, and ketones, leading to enhanced malty, fruity, and creamy aromas in FTB. Among these compounds, 3-methyl-1-butanol, phenylethyl alcohol, 1,2-propanediol, and 3-hydroxy-2-butanone play pivotal roles in shaping the flavor profile. High-throughput sequencing analysis identified Lactobacillus and Weizmannia as dominant bacteria, while Pichia or Issatchenkia was found to be dominant fungi. This study provides a theoretical foundation for the production of FTB through mixed fermentation with L. plantarum HYY-S10 and P. pastoris while contributing to the practical application of FTB production through mixed fermentation techniques. Collectively, our findings demonstrate that the 1:1 co-fermentation of L. plantarum HYY-S10 and P. pastoris is a promising strategy for developing novel fermented tea beverages with enhanced functional properties and complex, desirable flavors, offering valuable insights for the industrial production of specialty FTBs. Full article