Search Results (1,592)

Seasonal variation in aroma quality is critical for commercial grading of Xinyang Maojian (XYMJ) green tea, and how seasonal changes shape its volatile composition and aroma profile remains unclear. This study investigated the volatile profiles of XYMJ harvested in spring, summer, and autumn using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and odor activity value (OAV) analysis. A total of 93 volatile compounds were identified, with alkenes, alcohols, and esters being the most numerous chemical classes. Total volatile content decreased significantly seasonally (p < 0.05), being highest in spring (1716.68 μg/kg), followed by summer (1566.72 μg/kg) and autumn (1378.21 μg/kg). PCA and PLS-DA clearly distinguished seasons. Using a dual-filtering strategy (variable importance in the projection > 1.0 and p < 0.01), 14 differential volatile metabolites were identified as core seasonal markers. Geraniol, cis-jasmone, and indole were identified as key drivers of the premium floral fragrance in spring XYMJ, while cis-3-hexenyl hexanoate and linalool peaked in the summer harvest. OAV results and cross-modal sensory interaction principles suggest that the superior flavor of spring XYMJ arises from both higher aromatic intensity and an optimized aroma-taste balance. These findings provide useful insights into the seasonal variations in the metabolic and chemical profiles of XYMJ, enhancing our understanding of the biochemical markers associated with its production timeline. Full article

Gas-assisted steam explosion (GASE) disrupts raw material structures and promotes active release, but its effects on the nutritional quality and flavor of edible fungi remain unclear. Therefore, this study assessed the influence of GASE on the nutritional quality and flavor characteristics of Pleurotus eryngii. Using the sample as the raw material, we selected the GASE process parameters through single-factor experiments combined with response surface methodology and confirmation experiments. Subsequently, changes in nutrient contents and volatile/non-volatile flavor profiles were quantitatively characterized under these processing conditions. The results indicated that the selected parameters effectively disrupted the cell wall structure of the sample, resulting in a loose and porous microstructure. Consequently, the levels of protein, polysaccharides, amino acids and vitamins were significantly altered. In terms of flavor, this process modified the relative odor activity values of key aroma compounds, including volatile aldehydes and pyrazines, while also affecting the distribution of non-volatile metabolites. This led to the enrichment of flavor compounds such as nucleotides and their derivatives, and organic acids. This study confirmed that GASE technology can effectively enhance the nutritional quality and flavor characteristics of the mushroom by regulating its microstructure and metabolite composition. Full article

While withering is a critical processing step influencing the flavor profile of white teas, the effects of temperature-changing withering remain elusive. This study systematically investigated the variations in two withering methods (natural withering, temperature-changing withering) in volatile compounds of white teas made from four cultivars. The quality of white teas produced from ‘Mingshan No. 131’ (MS131), ‘Fuxuan No. 9’ (FX9), ‘Ziyan’ (ZY), and ‘Fudingdabai’ (FDDB) was evaluated using quantitative descriptive analysis (QDA), headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS), and odor activity value (OAV) analysis. The sensory evaluation results indicated that temperature-changing withering enhanced the development of sweet and fruity aromas while suppressing grassy notes. A total of 176 volatile compounds were identified, and temperature-changing withering induced significant alterations in the aroma profile, notably increasing the levels of ketones, esters, and alkenes (p < 0.05). Based on the criteria of OAV > 1, p < 0.05, and a fold change ≥ 1.5 (for upregulated compounds) or ≤0.67 (for down-regulated compounds), key volatile compounds in white teas from the four cultivars were identified. The common upregulated volatile compounds, namely 1-octen-3-one, cedrol, (E,E)-2,4-heptadienal, and (E)-2-hexenal, promoted the fresh flavor profile of white teas. These findings demonstrate that temperature-changing withering optimizes flavor-related metabolites, thereby providing a theoretical foundation for improving white tea processing. Full article

Citri Reticulatae Pericarpium (CRP), a traditional functional food with various cultivars, is widely used in spices and food additives. However, systematic comparisons of flavor and chemical profiles across mainstream cultivars remain lacking. This study systematically analyzed the flavor characteristics, volatile/non-volatile metabolic profiles, and antioxidant activity of six mainstream CRP cultivars. A total of 455 volatile organic compounds (VOCs) were identified, among which terpenoids showed distinct cultivar-specific accumulation and strongly affected aroma; 35 key VOCs were screened as pivotal contributors to distinct aroma profiles. Untargeted metabolomics identified 1289 non-volatile metabolites, among which polymethoxyflavones and flavonoid glycosides exhibited significant cultivar-specific accumulation. The six CRP cultivars showed five distinct metabolic accumulation patterns, which significantly affected the differences in bioactive compound accumulation and flavor formation among different cultivars. This study reveals the aroma formation basis and metabolic features of mainstream CRP cultivars, offering insights into CRP functional food development and genetic breeding. Full article

Traditionally, various herbs and spices are used to enhance the flavor and aroma of vegetable oils, but also to improve their nutritional value and stability. The aim of this work was to investigate the effects of sea fennel, an aromatic edible Mediterranean halophyte plant, leaf infusion, on the chemical composition of four unrefined edible vegetable oils (olive, sunflower, sesame and flaxseed oil). During the 90-day storage period, the quality parameters of the oils (peroxide value, free fatty acids and fatty acid profile), as well as their volatiles, were monitored. Free fatty acids and peroxide values increased in all samples, with the greatest increase in the olive oil (11% and 45%, respectively), while the effect on the fatty acid profile was negligible. Gas chromatography-mass spectrometry analysis showed the effect of oil aromatization by sea fennel components and confirmed the differences between oil samples. The results suggest that the addition of sea fennel to vegetable oils leads to changes in their chemical composition, and the parameters tested varied between the oils used. Full article

Musalais is a traditional fermented beverage of the Uyghur people in Xinjiang, China. Its production involves boiling grape juice at high temperatures to concentrate it and enhance its sugar content, followed by natural fermentation. However, this high-temperature concentration process leads to a significant loss of bioactive and flavor compounds, adversely affecting the quality of the final product. Adding composite ingredients may help mitigate this quality decline. This study compares Musalais new product with traditional Musalais. Phenolic analysis showed that total monomeric phenols were 182.36 mg·L⁻¹ in the new product versus 14.76 mg·L⁻¹ in traditional Musalais. Headspace solid-phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC-MS) identified 72 volatile compounds in the new product (total content of 569,848.88 μg·L⁻¹) compared to 58 compounds (total content of 362,774.17 μg·L⁻¹) in traditional Musalais. Compared to traditional Musalais, the new product exhibits a 24.14% increase in volatile compound variety and a 57.09% increase in total concentration, with more pronounced floral, fruity, and vinous aromas, as well as higher sensory scores. Non-targeted metabolomics suggests that the new product may have superior phenolic and volatile profiles. Full article

Variations in sweetness and bitterness among Madhuca longifolia flowers strongly influence their processing value and market acceptance, yet the chemo-diversity underlying these traits remains poorly characterized. This study aimed to unravel accession- and stage-specific differences by integrating physico-biochemical, elemental, and metabolic profiling across thirteen accessions (BM-1 to BM-13) from BUAT, Banda. Sensory and textural evaluations revealed wide diversity, with BM-5 displaying superior sweetness and aroma, whereas BM-6, BM-7, and BM-10 were differentiated by firmness, elasticity, and gumminess. Biochemical analyses across flower development showed that BM-5 consistently maintained higher sugars and β-carotene, while BM-1 exhibited marked reductions in sugars and total phenolics content; meanwhile, antioxidant activity increased with maturity, with BM-5 remaining the most stable. ICP-MS elemental analysis confirmed BM-5 as mineral-rich compared with lower-performing accessions. GC-MS metabolomic profiling of contrasting accessions (BM-1 and BM-5) across stages identified 303 volatile and semi-volatile metabolites, and multivariate analyses (PCA, VIP, volcano plots, pathway enrichment) revealed distinct stage- and accession-dependent patterns. Mature BM-5 was enriched in fermentation- and aroma-related metabolites such as melibiose, furfural, 5-HMF, and furaneol, whereas BM-1 accumulated defense-linked compounds including catechol, benzyl nitrile, and maltol. Overall, the integrated chemo-diversity landscape identifies BM-5 as a superior accession with high processing potential and value-addition prospects. Full article

This study introduced freeze-withering to resolve the conflict in traditional Taiping Kuihong black tea processing, where rolling enhances flavor but damages the integrity of the leaf shape. Using sensory evaluation, high-performance liquid chromatography, and gas chromatography–mass spectrometry, the effects of three freezing treatments (−20 °C, −80 °C, and liquid nitrogen at −196 °C) were analyzed and compared with traditional withering (CK). The results demonstrated that low-temperature treatments better preserved the morphological integrity of ‘two leaves and one bud.’ Compared to the CK group, the −20 °C low-temperature treatment group had a significantly higher proportion of esters among the volatile compounds in Taiping Kuihong black tea. Key floral fragrance components were abundant, while grassy undertones were greatly decreased. Concurrently, this group had the highest levels of theaflavins and TF/TR ratios. The −80 °C treatment was highly effective in preserving thearubigins; however, it resulted in a less complex fragrance profile with a reduced theaflavin level. Liquid nitrogen treatment caused aberrant accumulation of theabrownins, poor aroma harmony, and the lowest theaflavin level. This study indicates that −20 °C freezing withering is the best method for harmonizing the appearance and internal quality of Taiping Kuihong, giving critical evidence for targeted processing of unique black teas. Full article

Storage duration critically shapes the characteristic sweet and mellow quality of ripened pu-erh tea (RPT), yet the underlying chemical mechanisms remain poorly understood. This study investigated the sensory and chemical evolution of a representative commercial RPT product across a nine-year storage gradient (1, 3, 5, 7, and 9 years) by integrating Quantitative Descriptive Analysis (QDA), chromaticity measurement, targeted quantification of 42 non-volatile components, and Headspace Gas Chromatography–Mass Spectrometry (HS-GC-MS) volatilomics with multivariate statistical modeling. Prolonged storage drove systematic sensory maturation: the stale aroma gradually purified, and the taste profile transitioned significantly from heavy and mellow to sweet and mellow (p < 0.05), accompanied by a deepening infusion color with increased redness and yellowness indices. Targeted chemical profiling revealed significant decreases in total polyphenols and astringent esterified catechins, particularly epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) (p < 0.05), while theabrownins remained stable and soluble sugars peaked at intermediate storage stages. Pearson correlation analysis linked these chemical shifts to sensory perception, with enhanced sweetness, mouthfeel thickness strongly associated with reduced monomeric catechins and free amino acids (p < 0.001). Volatilomics combined with K-means clustering and relative odor activity value (ROAV) analysis revealed a dual mechanism of flavor refinement: progressive accumulation and increasing odor activity of aged aroma markers (1,2,3-trimethoxybenzene, β-ionone) coupled with systematic attenuation of pungent acids and grassy aldehydes. These findings, based on a single, standardized commercial product, elucidate the chemical-sensory foundation of the sweet and mellow profile in aged RPT and provide candidate markers and a transferable analytical framework for quality assessment of stored teas. Full article

This study investigated how three chili pepper varieties (Huanggong, millet, and long slender) affect fermentation dynamics, flavor formation, and microbial succession in spontaneously fermented chopped chili. Physicochemical analyses, sensory evaluation, GC–MS, electronic tongue analysis, and high-throughput sequencing were employed to characterize quality attributes, volatile flavor profiles, and microbial structures during the process. The results demonstrated that chili pepper variety significantly influenced fermentation behavior (pH range: 4.07–4.26; total acidity: 5.68–7.69 g/kg) and quality. Distinct differences were observed in acidification patterns, substrate utilization, sensory characteristics, and optimal fermentation stages Volatile flavor analysis revealed that chopped chili peppers produced from different varieties exhibited differentiated aroma profiles while sharing a common flavor framework composed of several key aroma-active compounds. Microbial community analysis indicated that the chili pepper variety drove distinct microbial succession patterns during the process, and dominant microbial groups showed significant correlations with the formation of specific flavor compounds. Overall, these findings demonstrate that chili pepper variety regulates flavor and quality formation in chopped chili peppers by modulating microbial community structure and metabolic activity, providing a scientific basis for raw material selection and targeted flavor control in fermented chili products. A total of 63–68 volatile compounds were identified across varieties, with OAV > 1 for 11–24 compounds. Three biological replicates were analyzed per time point. Full article

Air-dried mutton is a traditional, culturally significant meat product, yet its spontaneous fermentation is inherently constrained by unstable microbial communities, leading to batch-to-batch quality inconsistency and potential food safety hazards. Elucidating whether composite starter cultures can modulate the microbiota and enhance product quality is therefore critical for standardized industrial processing. Herein, we investigated the effects of a defined starter culture (composed of Lactiplantibacillus plantarum and Pediococcus pentosaceus in a 2:1 ratio, with a total inoculum of 10⁸ CFU/g) on the quality and flavor of air-dried mutton, comparing inoculated samples (FJ) with naturally fermented controls (ZR). The fermentation was conducted at 30 °C and 95% relative humidity (RH) for 24 h, followed by air-drying at 4 °C for 21 d, with all assays performed in three biological and three technical replicates. Starter inoculation significantly reduced the pH, water activity (Aw), total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) values while improving sensory acceptability (p < 0.05). Amplicon sequencing analysis revealed a lactic acid bacteria (LAB)-dominated microbiota in FJ samples, with elevated abundances of Pediococcus and Lactobacillus and reduced abundance of Pseudomonas. The inoculated group also exhibited altered eicosapentaenoic acid content and a more diverse volatile flavor profile, with eight key aroma compounds positively correlating with LAB abundance. These findings demonstrate that composite starter inoculation improves physicochemical quality, stabilizes the microbial community, and enhances flavor in air-dried mutton. Further mechanistic validation and scale-up trials are required to confirm industrial applicability. Full article

The flavor profile of Longmen rice vinegar directly influences consumer purchase intention, and understanding its variation during fermentation is crucial for final product quality control. In this study, the flavor dynamics during the fermentation of Longmen rice vinegar were systematically investigated. Sensory evaluation indicated that acidity increased significantly during the acetic acid fermentation stage, while alcoholic and fermented odors decreased continuously. Instrumental analysis identified 129 volatile compounds, predominantly esters, alcohols, and acids. Based on relative odor activity value (r-OAV) analysis, acetic acid, 3-methylbutyl acetate, 2,3-butanedione, benzeneacetaldehyde, phenethyl alcohol, ethyl acetate, 2-phenylethyl acetate, ethyl 4-methyl-pentanoate, 3-methyl-1-butanol, and 3-methylbutanal were determined to be the major contributors to the overall aroma. Orthogonal partial least-squares discriminant analysis (OPLS-DA) further screened 21 key differential compounds. Significant variations in organic acid and amino acid contents during fermentation were also observed. Correlation analysis revealed relationships between key aroma compounds and organic, as well as amino, acids. These findings establish a foundation for monitoring flavor dynamics during the fermentation of Longmen rice vinegar. Full article

The chemical composition and sensory profile of coffee are influenced by brewing method, namely extraction pressure, temperature, contact time, and equipment. This study compared coffee prepared with a traditional moka pot, a conventional espresso machine, and a novel Italian device (Kamira). Volatile compounds were analyzed by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS), leading to the determination of furan (34–42%), pyrrole (4–10%), and pyrazine (13–14%) derivatives. The most abundant fatty acids were palmitic (36–37%), linoleic (40%), and oleic (11%) acids. Physicochemical parameters (total solids, pH, and refractive index) were also measured. Caffeine and chlorogenic acids were quantified by liquid chromatography (HPLC). Differences in chlorogenic acids and volatile compounds were associated with variations in bitterness, acidity, astringency, and aroma intensity. Finally, a trained panel performed sensory evaluation to evaluate the olfactory and flavor attributes of the three types of coffee brews. Significant differences emerged among brewing systems. Espresso showed the highest caffeine content (55.3 ± 4.1 mg/100 g) and total solids (2.61 ± 0.11 g/100 g), together with a stable crema and intense sensory attributes. Moka coffee exhibited a rich aromatic profile but limited crema. The Kamira device produced an abundant crema and a chemical profile partially comparable to espresso. These findings confirm that brewing technology markedly affects coffee composition and sensory perception. Full article

Although solid-state fermentation (SSF) has long been used in food production in various traditional contexts, it is now emerging as a particularly promising strategy for the development of functional food ingredients from plant materials and agro-industrial side streams. This review examines recent advances in the application of SSF to enhance the nutritional, functional, sensory, and technological properties of food matrices. Current evidence indicates that SSF can increase the bioactive potential of plant-based substrates by promoting the release and biotransformation of phenolic compounds, while also improving antioxidant capacity, protein digestibility, and techno-functional performance. In addition, the process may support the formation of food-relevant metabolites, including vitamins, peptides, organic acids, and other secondary compounds, while reducing selected antinutritional, allergenic, and undesirable constituents. These compositional changes are often accompanied by modifications in aroma, volatile profiles, visual attributes, and, more recently, gut microbiota-related effects. Attention is given to the use of fungal-based processes for the valorization of cereals, legumes, fruit by-products, and other underutilized substrates. The review also addresses the growing industrial interest in SSF, especially in relation to mycelium-based foods, alternative proteins, functional ingredients, and feed applications. Despite its clear potential, the broader implementation of SSF will require further research and development to support its effective translation into food applications. Full article

Foeniculum vulgare Mill. (fennel) is an edible and medicinal plant cultivated worldwide. Owing to its distinctive aroma and diverse biological activities, its essential oils (EOs) have been widely investigated. However, available data predominantly focus on cultivated fennel or commercial EOs, while comprehensive investigations of wild-growing Mediterranean populations—particularly comparisons among different plant parts—remain scarce. In this study, EOs obtained by hydrodistillation from stems, leaves, flowers, and fruits of native Croatian fennel, were chemically characterised using gas chromatography-mass spectrometry (GC-MS), while antimicrobial activity was evaluated using the disc diffusion method against four bacterial strains. Additionally, the volatile profiles of fennel hydrolates were determined by headspace solid-phase microextraction (HS-SPME) and GC-MS analysis. Fennel flowers gave the highest EO yield (1.95%), followed by mature fruits (1.43%), whereas significantly lower yields were obtained from leaves (0.69%) and stems (0.58%). Trans-anethole was identified as the dominant constituent (from 40.96% in stems to 80.71% in fruits), while α-phellandrene predominated in stem EO (42.77%). Hydrolate volatile profiles were more complex—particularly leaf hydrolate, where 29 compounds were identified. The principal constituents were trans-anethole (39.58–57.40%) and fenchone (16.01–28.80%), while the highest content of estragole was observed in fruit hydrolate (6.56%). The EOs demonstrated moderate antimicrobial activity, showing effectiveness exclusively against Escherichia coli, likely attributable to high phenylpropanoid (primarily trans-anethole) and fenchone contents. Full article