Search Results (29)

Headspace–gas chromatography–ion mobility spectrometry (HS-GC-IMS) combined with chemometrics was employed to track volatile aroma compounds during the nine-steaming and nine-drying process. A total of 84 volatile signals (including monomers, dimers, and polymers) were tentatively identified, of which 73 volatile compounds were semi-quantified. Principal component analysis (PCA) revealed a mixed clustering pattern across cycles, indicating that unsupervised methods alone could not adequately resolve the volatile changes. A partial least squares discriminant analysis (PLS-DA) model supported clear chemical discrimination among the three hypothesized stages—early (cycles 1–3), middle (4–6), and late (7–9). Based on VIP > 1 and ANOVA (q < 0.05), 29 key differential compounds were screened and categorized into three dynamic groups (decreasing, transient, and accumulating), revealing three proposed transformation windows: green-grassy odor dissipation (cycles 1–3), roasted/malty aroma generation (cycles 4–6), and aroma stabilization via end-product accumulation (cycles 7–9). Relative odor activity value (ROAV) analysis revealed a decoupling between abundance and sensory impact: high-abundance Maillard products like maltol showed negligible ROAV (<0.0003), whereas esters and aldehydes dominated the ROAV profiles, suggesting their potential as important contributors to the fruity, sweet, and malty notes. The maltol/α-cedrol ratio (M/C) increased by an order of magnitude after the seventh steaming, and color parameters E*ab correlated negatively with ester accumulation. This study provides chemical insights and quantitative indicators for aroma quality control and process determination in black ginseng production. Full article

This study characterized the pattern and timing of post-cooking quality deterioration in durum wheat held at 25, 35, and 45 °C by performing physicochemical, microbiological, and volatile compound analyses combined with a sensorially defined off-odor onset endpoint. The bulk moisture content remained high throughout holding at all temperatures. Titratable acidity increased from 1.49 to 2.15, and pH at off-odor onset decreased from 6.63 to 6.49 with increasing temperature. Off-odor was detected after 50, 45, and 34 h at 25, 35, and 45 °C, respectively. Microbial growth was fastest at 35 °C (μ_max = 0.0651 h⁻¹). Thiobarbituric acid reactive substances (TBARS) values were slightly lower at 45 °C than at 25 °C, despite the shorter holding duration, whereas lipid oxidation-derived volatile aldehydes declined more sharply over the same comparison. This pattern, together with the earliest off-odor onset occurring at 45 °C, suggests that non-lipid-derived volatiles increasingly drive off-odor perception as holding temperature increases. Gas chromatography–mass spectrometry (GC–MS)-based relative odor activity value (ROAV) analysis identified 2-methoxy-4-vinylphenol, 2,4-decadienal, 2-nonenal, 2,3-butanedione, nonanal and 2-methoxyphenol as the principal contributors to the aroma profile. These findings indicate that off-odor development during post-cooking holding results from a temperature-dependent interplay between microbial and chemical deterioration pathways and provide a basis for optimizing holding time and temperature to delay off-odor onset and limit quality losses in bulgur production. Full article

2-acetyl-1-pyrroline (2-AP), the key volatile compound responsible for aroma in aromatic rice, is highly susceptible to abiotic stresses such as cadmium (Cd) toxicity. However, the potential role of molybdenum disulfide nanoflakes (MoS₂FL) in regulating antioxidant defense and 2-AP biosynthesis under Cd stress remains largely unexplored. In this study, a pot experiment was conducted to evaluate the effects of foliar MoS₂FL application on antioxidant defense, aroma formation, and Cd-stress mitigation in two fragrant rice cultivars, Meixiangzhan-2 and Basmati, grown in Cd-contaminated soil (50 mg kg⁻¹). Cadmium stress significantly reduced key enzymes and precursors involved during 2-AP biosynthesis, including Δ1-pyrroline-5-carboxylate synthetase (P5CS), Δ1-pyrroline, pyrroline-5-carboxylic acid (P5C), diamine oxidase (DAO) and proline dehydrogenase (PRODH), along with downregulation of their associated genes. In contrast, foliar application of MoS₂FL was associated with reduced Cd-induced oxidative stress, as indicated by increased antioxidant enzyme activities (SOD, POD, and CAT) and decreased malondialdehyde (MDA) accumulation. Moreover, MoS₂FL increased precursor accumulation, enzymatic activities, and transcript abundance of genes associated with 2-AP biosynthesis, whereas gamma-aminobutyric acid (GABA) content, betaine aldehyde dehydrogenase (BADH) activity, and BADH2 gene expression were significantly reduced. Consequently, MoS₂FL application significantly increased 2-AP content by 44.47% in Meixiangzhan-2 and 39.94% in Basmati under Cd stress. These findings suggest that MoS₂ nanoflakes may serve as a promising nano-enabled strategy to enhance antioxidant defense, improve aroma quality, and mitigate cadmium stress in fragrant rice, potentially through changes associated with the 2-AP biosynthesis pathway. This study highlights the potential application of nanomaterials in improving crop quality and stress resilience in sustainable agricultural systems. Full article

The growing demand for sustainable alternative proteins has intensified interest in fungal mycelia as a nutrient-dense biomass for food applications. This study compared Pleurotus ostreatus fruiting bodies with mycelia grown in liquid state on amaranth seed- and Bambara groundnut-based media, evaluating aroma-active volatiles and amino acid composition. Across 52 identified volatiles, C8 oxylipin-derived compounds dominated all matrices, with exceptionally high odour activity values (OAVs) for 1-octen-3-one (~4.1 × 10³), 3-octanone (~1.5 × 10³), 1-octen-3-ol (~8.3 × 10²) and 3-octanol (~5.3 × 10²). Amaranth-grown mycelia showed intensified mushroom/green/fatty notes due to elevated C8 ketones and unsaturated aldehydes, whereas Bambara-grown mycelia exhibited reduced C8 prominence and stronger malty, nutty and fermented nuances driven by Ehrlich-pathway aldehydes (e.g., 3-methylbutanal ~2.0 × 10³), with floral contributions from linalool (~3.8 × 10²). Mycelial protein contents ranged from 35.8 to 36.1 g/100 g (amaranth) and up to 38.2 g/100 g (Bambara), compared with 39.5 g/100 g in the fruiting body. Amino acid scores (AAS) identified cystine + methionine as limiting; mycelia exhibited higher AAS, with more indispensable amino acids exceeding reference requirements. Elevated glutamic and aspartic acids underscore the umami potential of the mycelial biomass. Overall, these plant-based substrates can strategically modulate both flavour chemistry and amino acid balance in P. ostreatus mycelia, supporting their use as nutritionally relevant, flavour-active ingredients in alternative protein and hybrid food systems. Full article

Royal jelly, a nutrient-rich bee product characterized by high water content and active components, is particularly susceptible to quality deterioration during storage. While temperature effects have been extensively documented, the specific role of light exposure in quality degradation remains largely unexplored. despite its relevance during production, handling, transportation, and display. This study systematically investigated the volatile organic compounds (VOCs) of royal jelly under different storage conditions using gas chromatography-ion mobility spectrometry (GC-IMS) combined with fingerprint analysis. Results from dual-column validation demonstrated that even short-term light exposure at 25 °C induced pronounced alterations in VOC profiles, triggering the accumulation of off-flavor aldehydes (e.g., hexanal, nonanal) and ketones, along with 2-furfural generated via Maillard reaction. Concurrently, characteristic fresh-aroma esters and alcohols were significantly depleted. Multivariate statistical analysis confirmed light exposure as the predominant factor driving quality deterioration, with temperature variation under dark conditions producing comparatively minor effects within the same short timeframe. This work provides the first systematic evidence establishing insights into early volatile changes in royal jelly and identifies key VOC markers that offer valuable insights for optimizing storage strategies and developing rapid quality monitoring protocols. Full article

In Chinese cuisine, seasoning oil enhances the aroma and appearance of dishes. This study examined how processing affects flavor release in multi-ingredient oils. Volatile organic compounds (VOCs), relative odor activity value (ROAV), and variable importance projection (VIP) were used to assess flavor changes. Optimal frying was 160 °C for 15 min with 11% green Sichuan peppercorn, 3% ghost pepper, 6% green onion, 0.1% bay leaf, 0.2% deseeded tsaoko, 0.5% star anise, 0.3% fennel seeds, 1.5% dried Erjingtiao chili, 5% ginger, and 2.5% red Sichuan peppercorn. Gas chromatography–ion mobility spectrometry (GC-IMS) and gas chromatography–mass spectrometry (GC-MS) analyzed heating at 150 °C, 160 °C, and 170 °C. Temperature strongly influenced VOC formation; 160 °C produced the most diverse VOCs, including aldehydes, ketones, terpenes, esters, and alcohols. Multivariate analysis identified 73 key compounds (VIP > 1) between 150 and 160 °C, but only 39 between 160 and 170 °C, indicating that high heat reduces complexity. Compounds such as 2-methylpyrazine and (E)-2-heptenal contributed caramel, nutty, buttery notes, with 2-methoxy-3-(1-methylethyl)-pyrazine as the core aroma. Frying at 160 °C balanced sweet, floral, and roasted aromas, offering guidance for precise seasoning oil flavor control. Full article

Efficient resource allocation during fruit expansion and ripening is critical for enhancing mango (Mangifera indica L.) productivity and fruit quality. A study was conducted to quantify the effects of foliar-applied GA₃ at concentrations of 0 (control), 50 (GA50), 100 (GA100) and 200 (GA200) mg L⁻¹, applied at 15, 25 and 35 days after full bloom, on fruit physiochemical attributes during the fruit expansion and ripening phases. In addition, metabolic profiling and pathway analysis were conducted after fruit ripening. Compared with the control, GA₃ application at 50, 100, and 200 mg L⁻¹ increased fruit length by 8, 12, and 14%, and fruit diameter by 5, 11, and 14%, respectively. The mean single-fruit weight was increased by 5–11% at physiological maturity. During the fruit expansion phase, GA₃ treatment decreased starch and total acidity by up to 11% and 29%, respectively, while increasing the soluble sugar content by 21%. Furthermore, enhanced antioxidant enzyme activities (SOD, POD, and CAT), accompanied by a reduction in malondialdehyde (MDA) contents in leaves, were observed. At the ripening stage, GA₃-treated fruits exhibited lower weight loss, higher firmness, more uniform color development, and reduced disease incidence, although vitamin C content and total soluble solids declined. PCA analysis identified GA100 as the optimal treatment. Metabolomics analysis revealed 287 differentially regulated metabolites between GA100 and the control. Sweet, fruity, and floral compounds were upregulated, whereas terpenoids and aldehydes were downregulated. KEGG pathway analysis indicated that GA100 modulated key resource-related metabolic pathways, including nitrogen, carbon and energy metabolism, thereby promoting efficient resource allocation toward fruit growth, quality, and aroma development. Overall, preharvest foliar application of GA₃, particularly at a concentration of 100 mg L⁻¹ (GA100), markedly improved mango fruit growth and quality but tended to simplify the aroma profiles by favoring ester production over complex terpenoid-derived notes. Full article

Although the aroma profile of Lentinula edodes has been extensively studied in fruiting bodies, the mycelial stage provides a distinct context for elucidating the fundamental metabolic pathways, free from the complexities of organismal development. To elucidate the mechanism underlying aroma differences between L. edodes strain 808 (the control strain) and its mutant strain ww808 (with almost no shiitake aroma), this study employed GC-IMS combined with PCA and OPLS-DA to identify key aroma biomarkers during the mycelial stage. All analyses were performed with three biological replicates. Furthermore, fatty acids composition, key enzyme activities of the LOX pathway, and their gene expression levels were systematically compared. The results indicated significant differences in the content of volatile aroma compounds in the mycelia of the two strains, primarily stemming from fundamental restructuring of gene expression and enzyme activity in the LOX pathway. The LOX gene expression and LOX activity of 808 mycelium were relatively high, facilitating the accumulation of key aroma compounds such as phenylethanal, benzaldehyde, and ethyl acetate, which constitute its distinctive aromatic profile. However, although the mycelium of ww808 possessed richer fatty acid precursor (C18:2), its lower LOX gene expression restricted the flux of this pathway. The significantly increased expression of ADH2, ADH3, and ADH5 genes and higher ADH activity enhanced the conversion capacity of aldehydes to alcohols and ketones. Given the generally higher odor thresholds of alcohols and ketones compared to aldehydes, distinct aroma profiles emerged between the two strains. Pearson correlation analysis further confirmed the significant correlations between the aroma biomarkers, fatty acids, key genes, and enzyme activities. This study revealed the formation mechanism of aroma differences in the mycelia of the two strains from the perspective of metabolic pathways, providing a theoretical foundation and candidate targets for the directed genetic improvement of L. edodes aroma quality. Full article

Storage time significantly influences the aroma quality of peanut oil. In this study, gas chromatography–mass spectrometry (GC-MS) and gas chromatography–ion migration spectrometry (GC-IMS) were used to analyze the volatile flavor compounds of hot-pressed peanut oil baked at two temperatures (140 °C and 160 °C, denoted as OPO and RPO, respectively) during storage. The two methods detected 80 and 76 volatile flavor compounds, respectively, and principal component analysis (PCA) revealed clear distinctions between OPO and RPO during the storage period. Ten key aroma compounds were identified based on relative odor activity value (ROAV) analysis, including 3-methylbutanal, hexanal, heptanal, octanal, benzeneacetaldehyde, 3-ethyl-2,5-dimethylpyrazine,2-ethyl-6-methylpyrazine, acetylpyrazine, 2-methoxy- 4-vinylphenol, and acetic acid. During storage, the degradation and transformation of flavor compounds were more pronounced in RPO than in OPO. Physicochemical analyses showed increased acid and peroxide values, concomitant with decreased vitamin E and phytosterol content. Notably, these parameters changed more slowly in OPO than in RPO, confirming that OPO maintained superior quality over time. Correlation analysis suggested that changes in the aldehyde and pyrazine contents are key indicators of flavor and quality evolution in peanut oil during storage. This study provides insights into how baking temperature and storage time affect peanut oil aroma, elucidating the mechanisms of flavor variation and offering a theoretical basis for optimizing the flavor and quality of hot-pressed peanut oil. Full article

Cannabis sativa L. exhibits a complex sensory profile governed by a diverse range of volatile and non-volatile compounds. Volatile constituents—such as terpenes, aldehydes, ketones, esters, and sulfur-containing compounds—together with non-volatile taste-active molecules including flavonoids and phenolic compounds, underlie its distinctive aroma and flavor. This review examines how genetic diversity, cultivation practices, and post-harvest processing modulate the synthesis, accumulation, and chemical transformation of these metabolites in the cannabis flower. It discusses recent advancements in the extraction, identification, and quantification of these compounds, highlighting the crucial integration of chemical characterization with sensory evaluation. By synthesizing findings from advanced analytical methodologies, this review addresses the challenges and opportunities involved in defining the sensory profiles of C. sativa L. varieties. Drawing insights from research on other consumer plants, strategies for future innovations are outlined, including the discovery of novel aroma and flavor compounds and the development of a universal cannabis aroma and flavor wheel. This work aims to support advancements in breeding programs, enhance product quality control, and guide future research in cannabis sensory science. Full article

Traditional smoking techniques, while historically valued for preservation and flavor enhancement, face limitations in aromatic diversity and safety, prompting exploration of spice-derived alternatives to meet modern culinary demands. This study explores the volatile compound profiles and aroma modulation of chicken wings smoked with four spices—cardamom, rosemary, mint, and rose—using a novel, household-friendly smoking protocol. The method combines air fryer pre-cooking (180 °C, 16 min) with electric griddle-based smoke infusion, followed by HS-SPME/GC-TOF/MS, relative odor activity value (ROAV) calculations, and metabolomic analysis. A total of 314 volatile compounds were identified across five samples. Among them, 45 compounds demonstrated odor activity values (ROAV) ≥ 1, contributing to green, woody, floral, and sweet aroma attributes. Eucalyptol displayed the highest ROAV (2543), underscoring its dominant sensory impact. Metabolomic profiling revealed a general upregulation of differential volatiles post-smoking: terpenes were enriched in wings smoked with cardamom, rosemary, and mint, while aldehydes and alcohols predominated in rose-smoked samples. An integrated screening based on ROAV and metabolomic data identified 24 key volatiles, including eucalyptol, β-myrcene, methanethiol, and α-pinene, which collectively defined the aroma signatures of spice-smoked wings. Spice-specific aroma enrichment and sensory properties were evident: rosemary intensified woody–spicy notes, mint enhanced herbal freshness, and rose amplified floral attributes. The proposed method demonstrated advantages in safety, ease of use, and flavor customization, aligning with clean-label trends and supporting innovation in home-based culinary practices. Moreover, it facilitates the tailored modulation of smoked meat flavor profiles, thereby enhancing product differentiation and broadening consumer acceptance. Full article

The quality of persimmon wine is closely related to various compounds, including polysaccharides. Polysaccharides are an essential class of macromolecules that modulate the wine’s chemical and physical characteristics by influencing the colloidal state or interacting with other compounds through non-covalent bonds. Polyphenols, on the other hand, exhibit antioxidant properties and effectively neutralize free radicals. This study employed Luotian sweet persimmons and Brassica napus (rapeseed) as core ingredients for producing functional fermented wine. Using GC-MS, rapeseed polysaccharides were subjected to trifluoroacetic acid hydrolysis and then derivatized via silylation for qualitative analysis of their monosaccharide composition. Molecular docking and molecular dynamics simulations were performed to provide molecular-level insights into the interactions between D-glucopyranose from rapeseed polysaccharides and quercetin, a polyphenol present in persimmon wine. The objective was to explore the binding mechanisms of these compounds during fermentation and to assess how these molecular interactions in-fluence the wine’s flavor and stability. In addition, volatile flavor compounds in two types of persimmon wine (pure persimmon wine and oleoresin-enriched persimmon wine) were qualitatively and quantitatively analyzed using headspace solid-phase microextraction (SPME) combined with gas chromatography–mass spectrometry (GC-MS). The results reveal that D-glucopyranose forms hydrogen bonds with quercetin, modulating its redox behavior and thereby enhancing the antioxidant capacity of persimmon wine. The results from four in vitro antioxidant assays, including DPPH, ABTS, FRAP, and vitamin C analysis, demonstrate that the addition of rapeseed flowers improved the antioxidant activity of persimmon wine. HS-SPME-GC-MS analysis revealed that esters, alcohols, and aldehydes were the primary components contributing to the aroma of persimmon wine. Persimmon wines with varying levels of oleoresin addition exhibited significant differences in the contents of key compounds, which subsequently influenced the aroma complexity and flavor balance. In conclusion, these findings provide reliable data and a theoretical foundation for understanding the role of rapeseed flower in regulating the aroma profile of persimmon wine. These findings also offer theoretical support for a deeper understanding of the fermentation mechanisms of persimmon wine while providing practical guidance to optimize production processes, ultimately improving both product flavor and stability. This study fills a critical academic gap in understanding microscopic molecular interactions during fermentation and offers a novel perspective for innovation in the fermented food industry. Full article

Honey is a sweet substance laboriously collected and crafted from nectar by bees, and since ancient times, it has been deeply cherished by humans for its unique flavor and nutritional value. Litchi honey stands out among various types of honey with its unique flavor and sweet taste, and it is particularly favored by consumers. In accordance with the testing methodologies specified in relevant Chinese national standards, we conducted an exhaustive analysis of the physicochemical properties of six litchi honey samples in Southern China. The results showed that the moisture content fell within a range of 17.18% to 22.7%, while the electrical conductivity remained below 0.28 mS/cm, and amylase activity surpassed 7.7 mL/(g·h). The fructose content varied from 36.5% to 39.6%, with glucose content ranging between 30.57% and 37.63%. The combined total of these two monosaccharides was found to be within the spectrum of 69.63% to 77.23%, and sucrose content was recorded between 0.59% and 1.15%. The F/G was between 1.05 and 1.28, the proportion of fructose in reducing sugars ranged from 51.28% to 56.22%, and the maltose content was between 1.09% and 1.51%. The HMF content was measured between 1.04 and 3.49 mg/kg. Moreover, the presence of C-4 plant sugars was absent in all tested honey samples. These results definitively demonstrate that the physicochemical attributes of all litchi honey samples align with the standards set forth by Chinese national regulations and international authorities such as CODEX. During our in-depth examination of volatile constituents, we identified 26 common compounds, with trans-linalool oxide, linalool, lilac aldehyde B, lilac aldehyde D, α-terpineol, and cedrol emerging as pivotal in crafting the unique flavor and aroma profile of litchi honey. Additionally, the detection of methyl cyclosiloxane in litchi honey has garnered our attention, necessitating a comprehensive investigation into the honey production process. In conclusion, this study not only establishes a robust scientific basis for the quality assurance and product development of litchi honey but also provides valuable reference information for consumers in their selection of honey products. Full article

Lichuan black tea (LBT) is a well-known congou black tea in China, but there is relatively little research on its processing technology. Echa No. 10 is the main tea tree variety for producing LBT. This study investigated the sensory quality, flavor components, and bioactivity of Echa No. 10 Lichuan black tea (LBT) at different drying temperatures (70, 80, 90, 100, 110, 120, and 130 °C). During 80–120 °C, increasing the drying temperature enabled a higher sweet aroma concentration and enhanced the sweetness in the taste, in contrast to reducing the floral, fruity, and sweet aromas, and increasing the bitterness and astringency, at >120 °C. Additionally, with an increasing drying temperature, the contents of tea polyphenols and total catechins significantly decreased, with the theaflavins decreasing first and then increasing, and the alcohols, aldehydes, esters, and hydrocarbons increasing first and then decreasing. Meanwhile, compounds (including linalool, (Z)-linalool oxide (furanoid), (E)-linalool oxide (furanoid), cis-β-Ocimene, and methyl salicylate) contribute more to the floral and fruity aromas at <110 °C. Furthermore, low-temperature drying favors the antioxidant and inhibitory effects of the α-amylase, α-glucosidase, and glucose absorption activity. Both the tea quality and bioactivity results revealed 80–110 °C as the optimal drying temperature range for LBT. Full article

The aim of this study was to identify the aromatic compounds present in different apple varieties and to gain insights into the changes in the aromatic compounds during ripening. Three apple varieties (“Red Astrachan”, “Ning Qiu”, and “Golden Delicious”) at different stages of ripening were selected for this study; their peel and pulp were analyzed via headspace solid-phase microextraction (HS-SPME)–gas chromatography–mass spectrometry (HS-SPME-GC-MS), and 30 volatile compounds were identified. The samples’ differences were analyzed using heat map cluster analysis, principal component analysis (PCA), and an independent samples t-test. The results showed that the content of aromatic compounds in the peel was higher than that in the pulp. The relative content of esters in the aromatic compounds of the three apple varieties followed the order of pulp > peel and “Ning Qiu” > “Golden Delicious” > “Red Astrachan”. This suggests that “Ning Qiu” combines the advantages of its parents in terms of its aroma content. The highest concentrations of aroma compounds in “Red Astrachan” and “Ning Qiu” accumulate before the ripening stage, and care should be taken to choose an appropriate harvesting time according to the different needs during production. The main compounds of “Red Astrachan” are aldehydes and C8 esters, while those of “Ning Qiu” and “Golden Delicious” are alkenes and esters. After analyzing the relative odor activity values (rOAVs) of key volatile compounds and their aroma descriptors during the harvest period, acetic acid pentyl ester, butanoic acid hexyl ester, hexanoic acid hexyl ester, and 2-ethyl-1-Hexanol were found to contribute the most to the overall flavor of the peel and pulp. “Ning Qiu” combines the parental advantages of the concentrated peel of “Red Astrachan” and the astringent pulp of “Golden Delicious”, with compounds in its composition that give a pleasing aroma. Mature “Ning Qiu” fruits have a more intense aroma and fruity flavor. The development of flavor-specific varieties has provided the theoretical basis for future research in molecular hybridization, molecular-assisted breeding, and the molecular biology of apple flavor synthesis and metabolism. Full article