Search Results (966)

Jackfruit seeds (JFSs) are an underutilized agro-industrial by-product with considerable nutritional and functional potential for sustainable food fermentation. This study evaluated the feasibility of using jackfruit seed flour as a partial malt substitute in beer brewing at replacement levels of 0%, 25%, 50%, and 75% (w/w). Fresh jackfruit seeds were processed into flour, gelatinized, and mashed with pale ale malt in the presence of α-amylase before fermentation with Saccharomyces cerevisiae, Lutra kveik ale yeast. The physicochemical properties of the raw materials, starch hydrolysis during mashing, beer quality attributes, and volatile aroma compounds were investigated. Compared with pale ale malt, JFS contained higher crude protein (13.22%), total phenolic content (476.66 mg GAE/100 g), and antioxidant activity. HPLC-IR analysis demonstrated the formation of fermentable sugars during mashing, although starch conversion from JFS remained incomplete at higher substitution levels. Increasing JFS substitution significantly enhanced beer foamability (up to 142.22%) and foam stability (112.84 s), which was attributed to the higher protein content of the seeds. However, beers containing higher proportions of JFS exhibited darker color and increased turbidity, reaching 680 NTU at 75% substitution. HS-SPME-GC-MS analysis revealed changes in alcohols, esters, and ketones with increasing JFS substitution. These findings demonstrate that jackfruit seed flour can serve as a sustainable malt adjunct for beer production, improving selected quality attributes while valorizing agricultural by-products. The study highlights the potential of jackfruit seeds as a functional brewing ingredient that supports the development of sustainable and next-generation fermented beverages. Full article

Huangshui (HS), fermented grains (FG), and pit mud (PM) are closely connected during the fermentation of Nongxiangxing baijiu (NXB); however, the contribution of HS to the differences in flavor profiles across PM, FG, and distilled baijiu has not been fully elucidated. Herein, instrumental techniques of electronic nose (E-nose), headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS) were used to compare the volatile profiles of HS, FG, PM, and two quality grades of NXB. E-nose analysis revealed that PM exhibited stronger signals related to sulfur-containing, organic, and terpene-associated compounds. Gas chromatography indicated that special-grade baijiu had a more favorable ethyl caproate/ethyl lactate ratio than superior-grade baijiu. Furthermore, HS-GC-IMS revealed different volatile profiles of the samples. Up to 183 volatile organic compounds (VOCs) were identified via HS-SPME-GC-MS, with esters and acids being the dominant classes. Multivariate analysis showed close relationships among HS, FG, and PM, and 35 VOCs were identified as important discriminatory compounds. These results suggest the differences and similarities in VOCs among the HS, FG, PM, and NXB samples, indicating that HS is chemically associated with both FG and PM. This study provides useful insights into HS utilization and quality regulation of NXB through the effective management of HS. Full article

Thymbra capitata (L.) Cav. is an aromatic Mediterranean species widely used as a culinary herb and valued for its medicinal properties. The present study investigated the volatile composition of different plant organs (petals, sepals, leaves, and roots) collected in Jerusalem, Israel, using three complementary GC-MS approaches: solvent extraction (Liq), static headspace (HS), and solid-phase microextraction (SPME). The influence of air-drying on volatile composition was also evaluated. Among the analytical methods tested, HS provided the broadest volatile profile with 57 identified compounds, whereas Liquid extraction yielded the highest relative abundances of thymol and carvacrol. SPME proved particularly effective for the detection of sesquiterpenes, especially β-caryophyllene. The volatile profiles differed considerably among plant organs. Floral and vegetative aerial parts were characterized by high proportions of p-cymene, γ-terpinene, thymol, and carvacrol, whereas roots exhibited a distinct composition dominated by α-pinene, limonene, and β-caryophyllene. Drying modified the relative abundances of several major constituents without changing the characteristic volatile profile of the species. Multivariate analysis revealed close relationships between selected aerial organs and confirmed that phenolic monoterpenes were the principal contributors to chemical variability within the plant. The results demonstrate that HS, SPME, and solvent extraction provide complementary information and together enable a comprehensive characterization of T. capitata volatiles. These findings contribute to understanding organ-specific phytochemical variability and support the selection of appropriate analytical and processing strategies for aromatic and medicinal plants. Full article

The use of different light qualities during the spreading stage can influence the flavor of green tea. In this study, freshly harvested leaves were exposed to red (GRL), yellow (GYL), blue (GBL), or natural light (GCK, as the control) throughout spreading. The resulting tea quality was subsequently evaluated through sensory assessment, combined with HS-SPME-GC-MS and UPLC-MS/MS analyses. The results showed that blue light significantly increased free amino acid content and promoted the accumulation of compounds associated with freshness. Yellow light treatment enhanced aroma substances, with 2(5H)-furanone, 5-ethyl-3-hydroxy-4-methyl, benzenemethanethiol, and 3-buten-2-one, 4-(2,6,6-trimethyl-1-cyclohexen-1-yl) detected at the highest levels in this group, contributing to the highest sensory aroma score. In contrast, the GRL group exhibited the lowest levels of aroma compounds, although its sensory score remained relatively high. The GCK group exhibited more pronounced chestnut-like aroma characteristics but received the lowest sensory score. Overall, blue light promotes a fresh and rich taste, whereas yellow light contributes more substantially to the development of aromatic characteristics. These findings indicate that adjusting light quality during the spreading stage can improve the flavor quality, providing a potential strategy for optimizing green tea processing practices. Full article

This study developed an ABTS-targeted sequential fermentation strategy for fermented apple beverages using Metschnikowia sp. Mp58 belonging to the M. pulcherrima clade (Mp) and Lactiplantibacillus plantarum Cro3-2 (Lp). Thirteen Metschnikowia isolates and ten Lactiplantibacillus isolates were initially screened according to their effects on ABTS radical-scavenging activity, after which Mp58 and Cro3-2 were selected for further investigation. Different fermentation strategies were compared, and sequential inoculation of Mp followed by Lp produced the highest ABTS radical-scavenging activity. Single-factor experiments, an orthogonal design, and response surface methodology were subsequently used to optimize the inoculation interval, fermentation temperature, and total fermentation time, with ABTS radical-scavenging activity as the sole response variable. The selected conditions consisted of Mp inoculation at 0 h, Lp inoculation after 25 h, and fermentation for a total of 46 h at 21.50 °C. The experimentally obtained ABTS radical-scavenging activity was 78.17 ± 0.49%, which was close to the model-predicted value. Under the selected conditions, Mp–Lp sequential fermentation significantly altered the physicochemical, bioactive, in vitro functional, and volatile characteristics of the apple beverage. Compared with the uninoculated control, total phenolic content, total flavonoid content, and ascorbic acid content increased by 73.08%, 32.97%, and 7.14%, respectively. These changes were accompanied by increases of 41.00%, 39.77%, and 37.86% in ABTS radical-scavenging activity, DPPH radical-scavenging activity, and ferric reducing antioxidant power, respectively. The Mp–Lp beverage also exhibited the highest α-glucosidase and α-amylase inhibitory activities, reaching 85.97% and 78.35%, respectively, as well as bile salt-binding capacities of 51.57% for sodium glycocholate and 54.97% for sodium taurocholate. Ethanol accumulation remained limited under the tested conditions, although concentrations below the measurement capability of the distillation–hydrometer method could not be excluded. A total of 95 volatile compounds were tentatively identified by HS-SPME-GC-MS. The sequentially fermented beverage contained a larger number of detected volatile compounds than the single-strain fermented beverages and showed treatment-associated changes in the relative distribution of esters, alcohols, and fatty acids. Exploratory PCA and OPLS-DA indicated differences in volatile composition among treatments, while nonanoic acid, ethyl hexanoate, n-decanoic acid, isophorone, and (E)-2-hexen-1-ol were identified as candidate compounds associated with group separation. These chemical changes should not be interpreted as direct evidence of improved aroma or sensory quality in the absence of sensory evaluation. Overall, Mp–Lp sequential fermentation represents a potentially useful bioprocessing strategy for modifying the bioactive properties, in vitro functional indicators, and volatile composition of fermented apple beverages. Full article

Originating from Hunan Province, China, Huangjin green tea (HJGT) is known for its diverse aromas, including green, floral, and chestnut-like, but their characteristic volatile components remain unclear. In this study, 111 volatiles were identified from 26 HJGT samples using HS-SPME-GC-MS. Floral HJGT showed the highest relative content of ester, chestnut-like HJGT was richest in sulfur-containing compounds, and green HJGT was dominated by alcohols. Partial least-squares discriminant analysis identified 61 differential volatiles (VIP > 1), whose distribution patterns across aroma types fell into four categories. Based on relative odor activity value (≥1) and ANOVA (p < 0.05), 26 key aroma-active compounds were further screened. Ten characteristic compounds, such as linalool, indole, and dimethyl sulfide contributed floral, fresh, green, cabbage, and violet-like notes to floral HJGT. Seven compounds, including heptanal, nonanal, and 2-pentylfuran, imparted nutty, waxy, pungent, and beany notes to chestnut-like HJGT. Nine compounds, including geraniol, hexanal, and phenylethyl alcohol, contributed green, floral, fragrant, and minty notes to green HJGT. These findings elucidate the chemical basis of HJGT aroma and provide a theoretical foundation for the targeted regulation of its aroma types in production. Full article

This study investigated quality traits and volatile organic compounds (VOCs) in two winter wheat varieties with different gluten types (Xinliang 169, medium-strong gluten, and Xinliang 607, medium-weak gluten) across five grain-filling stages (5, 10, 20, 30, and 40 days after anthesis, DAA) under heated headspace conditions (80 °C). During grain filling, moisture and total soluble sugar (TSS) decreased significantly, whereas hardness, thousand-kernel weight (TKW), and starch content increased significantly. Protein followed a typical “high–low–high” pattern. Using headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS) and headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS), 80 and 125 VOCs were detected, respectively. A total of 19 preliminarily prioritized candidate odorants (e.g., 1-penten-3-one, 2,3-butanedione, and 3-methylbutanal) were screened using orthogonal partial least squares discriminant analysis (OPLS-DA, VIP > 1) and relative odor activity value (ROAV ≥ 1). Based on literature odor descriptors, the aroma profile shifted from green, malty notes during early grain filling to waxy, fatty, and grain-like notes during late grain filling. XL169 was characterized by grassy-green, malty, and fatty grain-like notes, whereas XL607 was dominated by creamy, buttery, and sweet-fruity woody notes. Correlation analysis revealed significant correlations between high-priority candidate odorants (2,3-butanedione, (E)-2-octenal, and 3-hydroxy-4,5-dimethyl-2(5H)-furanone) and quality traits (starch, TSS, and protein). These exploratory findings provide a preliminary reference profile for understanding how grain filling affects wheat VOCs. Full article

Traditional fermented sausages are widely consumed in China but often face quality and safety risks due to contamination by spoilage and pathogenic microorganisms during natural fermentation. This study investigated the effect of Litsea cubeba essential oil (LCEO) on the microbial community structure and volatile flavor compounds (VFCs) of fermented sausages using multi-omics approaches, including 16S/ITS amplicon sequencing and HS-SPME-GC-MS. The results showed that LCEO significantly altered the microbial community, increasing the relative abundance of Lactobacillus from 4.65% to 76.22% and Debaryomyces from 11.95% to 22.35%, while reducing Staphylococcus and Aspergillus by 47.01% to 4.55% and 37.28% to 17.09%, respectively. A total of 695 VFCs were identified, with terpenoids and hydrocarbons being the most abundant. A differential analysis revealed that LCEO enhanced the relative content of key aroma-active compounds, including ethyl esters and aldehydes, with odor activity values exceeding 1 for fruity-related compounds such as decanoic acid, ethyl ester and nonanoic acid, methyl ester. Strikingly, the elevated levels of these fruity esters translated into significantly higher sensory scores for odor (p < 0.05) in LCEO-treated sausages, as panelists consistently perceived a pronounced fruity and fresh aroma profile, ultimately leading to a superior overall acceptability compared to the control. A correlation analysis indicated strong positive associations between Lactobacillus, Debaryomyces, and major flavor-contributing esters. In conclusion, LCEO potentially reduces the microbial risks and improves the flavor profile of fermented sausages, making it a promising natural additive for meat fermentation. Full article

Volatile fingerprints provide useful information for characterizing Astragali Radix (AR), a food–medicine homologous plant material, but differences among wild, wild-simulated, and cultivated samples remain unclear. In this study, headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC–MS) and headspace gas chromatography–ion mobility spectrometry (HS-GC–IMS) were integrated with multivariate analysis and interpretable machine learning to characterize volatile profiles and identify candidate discriminatory compounds in 117 AR samples from different cultivation patterns. HS-SPME-GC–MS tentatively identified 29, 34, and 45 volatile compounds in wild, wild-simulated, and cultivated samples, respectively. Esters were the predominant class in all groups, although the relative abundance of esters and the overall chemical-class composition varied among cultivation patterns. HS-GC–IMS tentatively identified 57, 50, and 55 compounds, respectively, comprising mainly low-molecular-weight aldehydes, alcohols, and ketones and thereby providing complementary volatile fingerprint information. Partial least squares discriminant analysis (PLS-DA) showed that the volatile fingerprints captured cultivation-pattern-associated differences, with the HS-GC–IMS model showing clearer group separation. Random forest, support vector machine, and CatBoost models were further constructed using the HS-SPME-GC–MS profiling results. By integrating variable importance in projection (VIP) and SHapley Additive exPlanations (SHAP) values, γ-hexalactone, methyl eugenol, methyl (9Z,11E)-octadeca-9,11-dienoate, eugenol, and ethyl linoleate were selected as candidate discriminatory compounds. Based on the HS-GC–IMS results, 1-octen-3-one, pentyl acetate, (Z)-2-penten-1-ol, 2-heptanone, and the monomeric signal of 2-ethyl-6-methylpyrazine were also identified as candidate discriminatory compounds. These compounds may be related to fatty acid-derived metabolism, aromatic secondary metabolism, and terpenoid-related processes. The integration of two complementary volatile-analysis platforms with VIP- and SHAP-based interpretation provided broader coverage of volatile features and improved the interpretability of candidate-compound screening. These findings provide an interpretable analytical workflow and candidate discriminatory compounds that may support future rapid screening, cultivation-pattern authentication, and volatile-profile-based differentiation of AR, pending independent external validation. Full article

The spotted-wing drosophila, Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae), is an invasive pest causing substantial economic losses in berry production worldwide. Reliable monitoring is essential for effective integrated pest management; however, information on the field performance of locally produced vinegar-based attractants remains limited. This study compared the attractiveness of four vinegar-based attractants (homemade grape vinegar, homemade hawthorn vinegar, homemade apple vinegar, and commercial apple vinegar) for monitoring D. suzukii in blackberry (Rubus spp.) and blueberry (Vaccinium spp.) orchards in southeastern Türkiye during the 2023 and 2024 growing seasons. In addition, the volatile organic compound (VOC) profiles of the attractants were characterized using headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC–MS). A total of 80,571 adult flies were captured during the study. Significant differences among attractants were detected in all host plant–year combinations (one-way ANOVA, p < 0.001). Generalized linear mixed model analysis further demonstrated significant effects of the host plant, attractant type, sampling week, and year on weekly trap captures (p < 0.05). Homemade grape vinegar consistently produced the highest trap captures, whereas commercial apple vinegar showed the lowest trapping performance. Fourteen volatile compounds belonging mainly to carboxylic acids, alcohols, esters, aldehydes, and monoterpenes were identified, revealing differences in the volatile profiles of the evaluated attractants. Overall, homemade grape vinegar proved to be the most effective vinegar-based attractant under the conditions of this study and represents a practical, low-cost option for monitoring D. suzukii in berry orchards. Further studies incorporating replicated chemical analyses and behavioural bioassays are needed to clarify the contribution of individual volatile compounds to insect attraction. Full article

Taiwanofungus camphoratus, an edible and medicinal fungus endemic to Taiwan, produces a distinctive and complex fragrance during mycelial growth, indicating its potential as a source of natural flavor compounds for food and cosmetic applications. However, few research efforts have focused on changes in its flavor-related metabolites and the related underlying molecular mechanisms remain largely unexplored. In this study, we found that the water extract of Cinnamomum camphora leaves (CC water extract) markedly stimulated T. camphoratus mycelial growth, increasing biomass by 29.7% in liquid fermentation. Integrated transcriptomics, UPLC-based metabolomics and HS-SPME-GC-MS analyses revealed that CC water extract could enhance metabolic fluxes through glycolysis, the pentose phosphate pathway, and galactose metabolism, thereby supporting mycelial growth and the accumulation of flavor-related metabolites. Specifically, CC water extract promoted the abundance of metabolites associated with mushroom-like, floral, and fruity aroma profiles, together with sweet taste-related metabolites. These findings provide new insights into optimizing the liquid fermentation processes and flavor profiles of T. camphoratus mycelia, providing a reference for better utilizing this valuable fungal resource. Full article

In this study, honey samples collected from the Varda Plateau (İkizdere Valley, Rize) and Yusufeli regions of northeastern Türkiye were comprehensively characterized in terms of their melissopalynological, physicochemical, elemental, and volatile properties. Ten honey samples collected from different apiaries were analyzed. Melissopalynological results identified two samples as monofloral Castanea sativa (chestnut) honeys and three samples as Myosotis-dominant honeys, while the remaining samples were classified as multifloral. The pollen spectra reflected the rich floristic diversity of the region, shaped by both forest vegetation and high-altitude herbaceous flora. Moisture and proline analyses indicated that the investigated samples were consistent with the characteristics of natural and well-matured honeys. Volatile compound analysis by HS-SPME/GC–MS revealed substantial qualitative and quantitative differences among samples, with chestnut and Myosotis honeys generally exhibiting more distinctive aroma profiles than multifloral honeys. Benzaldehyde, furfural, nonane, and linalool derivatives were among the most frequently detected volatile compounds, although their relative abundances varied considerably among samples. Elemental analysis identified potassium as the predominant mineral in all honey samples, while significant variability was observed for Fe, Zn, Mn, Ni, and Cu concentrations. Particularly, the Yusufeli samples were characterized by markedly higher Fe and Cu contents than the Varda samples, indicating a strong geographical influence on elemental composition. Multivariate analyses, including PCA, HCA, and UpSet analysis, confirmed considerable compositional heterogeneity and demonstrated that both botanical and geographical origins contribute to honey differentiation. Overall, the findings provide new insights into the chemical and botanical characteristics of chestnut, Myosotis, and multifloral honeys from the Eastern Black Sea region and highlight the value of integrated analytical and chemometric approaches for honey characterization, classification, and origin assessment. Full article

Understanding olive tree metabolism and its interactions with biotic and abiotic factors is crucial for the sustainability and resilience of olive cultivation in a changing agroclimatic context. In response to biotic stress, plants activate complex signaling pathways that trigger the production of specialized metabolites, particularly volatile organic compounds (VOCs). This study investigates the volatolomic profile naturally emitted by whole olive fruits using an integrated metabolomic strategy that combines design of experiments (DoE), targeted and untargeted analyses, and multivariate statistics. Optimal headspace solid-phase microextraction (HS-SPME) conditions were established using 30 g of sample, a 50 °C extraction temperature, a 50 min extraction time, and a 3 min injection at 250 °C, identifying extraction time and temperature as the most critical factors influencing VOC recovery. The data demonstrated significant cultivar-dependent variation in the volatile emissions from healthy olive fruit among six representative varieties. Furthermore, robust partial least squares-discriminant analysis (PLS-DA) and random forest models provided a clear separation between healthy and damaged olive fruits, achieving high predictive accuracy (90%) and identifying key volatile biomarkers derived from the lipoxygenase (LOX) pathway. This novel multivariate optimization approach (SPME–GC/MS) represents a powerful tool for establishing a reliable chemical fingerprint of the olive fruit “volatilome” under evolving agroclimatic challenges. Full article

The lipoxygenase (LOX) pathway plays a crucial role in the biosynthesis of characteristic aroma compounds in fruit. Despite the progress in understanding the LOX pathway in model plants like tomato, the distinct roles of individual members within the LOX gene family in flavor formation in the complex octoploid strawberry are still not fully understood. In this study, we identified 13 LOX genes in the strawberry genome and focused on a specific lipoxygenase gene, designated FaLOX11, which exhibited the highest expression during fruit ripening. Spatiotemporal expression analysis revealed that FaLOX11 expression was significantly correlated with 3-hexenal accumulation, quantified via headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS). Functional characterization via transient overexpression of FaLOX11 in strawberry fruits resulted in a significant increase in C6 volatile content, specifically a ~72% increase in 3-hexenal content. Conversely, RNA interference (RNAi)-mediated transient silencing of FaLOX11 significantly downregulated the expression of this gene and led to a marked reduction in the production of these key aroma compounds. Our findings demonstrate that FaLOX11 acts as a positive regulator of C6 aldehyde and alcohol biosynthesis, thereby playing a pivotal role in determining the characteristic aroma profile of strawberry fruit. This study provides new insights into the LOX pathway in strawberry and lays a solid molecular foundation for improving strawberry flavor quality. Full article

Quince (Cydonia oblonga Mill.) is an important fruit crop, yet a systematic quality evaluation framework is lacking. This study comprehensively characterized multiple germplasms from distinct production areas. An integrated strategy combining physicochemical analysis, FT-MIR (Fourier transform mid-infrared spectroscopy), electronic nose (E-nose), headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS), and chemometrics was employed. Significant variations were observed among accessions: certain varieties were observed to exhibit the highest pectin (1.86%) and total phenolic content (143.40 mg/100 g), while others showed superior firmness and titratable acidity. β-Damascenone in one accession was found to have an exceptionally high odor activity value (OAV) of 265.05. Multivariate analysis, including PLS-DA and OPLS-DA, effectively discriminated among quince accessions, with PLS-DA achieving 100% classification accuracy, and tentatively identified 18 key markers (VIP > 1) for accession discrimination. Loading scatter plot analysis further validated the contribution of these markers to the separation between accessions. However, due to the limited sample size (n = 18) and partial confounding between cultivar and origin, these findings should be considered exploratory and require validation in larger independent studies. This work provides preliminary insights into the diversity and geographical patterns of quality and flavor traits in quince germplasm, offering a preliminary foundation for germplasm evaluation and targeted utilization. Full article