Search Results (158)

Background: Phoebe zhennan and Phoebe chekiangensis are valuable evergreen trees recognized for their unique aromas and ecological significance, yet the organ-related distribution and functional implications of aroma-active volatiles remain insufficiently characterized. Methods: In this study, we applied an integrated GC-MS-based volatile metabolomics approach combined with a relative odor activity value (rOAV) analysis to comprehensively profile and compare the volatile metabolite landscape in the seeds and leaves of both species. Results: In total, 1666 volatile compounds were putatively identified, of which 540 were inferred as key aroma-active contributors based on the rOAV analysis. A multivariate statistical analysis revealed clear tissue-related separation: the seeds were enriched in sweet, floral, and fruity volatiles, whereas the leaves contained higher levels of green leaf volatiles and terpenoids associated with ecological defense. KEGG pathway enrichment indicated that terpenoid backbone and phenylpropanoid biosynthesis pathways played major roles in shaping these divergent profiles. A Venn diagram analysis further uncovered core and unique volatiles underlying species and tissue specificity. Conclusions: These insights provide an integrated reference for understanding tissue-divergent volatile profiles in Phoebe species and offer a basis for fragrance-oriented selection, ecological trait evaluation, and the sustainable utilization of organ-related metabolic characteristics in breeding and conservation programs. Full article

Investigating the volatiles isolated from a commercial spirulina (Arthrospira platensis) dietary supplement by gas chromatography–olfactometry (GC–O) in combination with an aroma extract dilution analysis (AEDA) resulted in 29 odor events with flavor dilution (FD) factors between 8 and 2048. Identification experiments, including various offline and online fractionation approaches, led to the structure assignment of 30 odorants, among which the most potent were sweaty 2- and 3-methylbutanoic acid (FD 2048), roasty, earthy, shrimp-like 2-ethyl-3,5-dimethylpyrazine (FD 2048), vinegar-like acetic acid (FD 1024), and floral, violet-like β-ionone (FD 1024). Static headspace dilution analysis revealed sulfuric, cabbage-like methanethiol (FD factor ≥ 32) as an additional potent odorant. In summary, 31 important spirulina odorants were identified in this study, and 14 were reported for the first time as spirulina constituents. Our data will provide a basis for future odor optimization of spirulina-based food products. 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

Wuyi Shuixian tea, a premium oolong tea known for its complex floral-fruity aroma, exhibits significant quality variations across different grades. This study systematically analyzed the aroma characteristics and key fragrant compounds of four grades (Grand Prize SA, First Prize SB, Outstanding Award SC, and Non-award SD) using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), odor activity value (OAV) analysis, and multivariate statistical methods. A total of 159 volatile compounds were identified, with similar compound categories but distinct concentration gradients between grades. OAV-splitting analysis (based on OAV ≥ 1 as the threshold for aroma activity) identified β-ionone (fruity), octanal (fatty), and linalool (floral) as core aroma-active contributors, as their OAV values significantly exceeded 10 in awarded grades (SA, SB, SC), indicating dominant roles in sensory perception. Notably, linalool, a floral marker, showed a concentration gradient (SA > SB > SC) and was absent in SD, serving as a critical determinant of grade differentiation. Orthogonal partial least squares-discriminant analysis (OPLS-DA) further distinguished awarded grades (SA, SB, SC) by balanced fruity, floral, and woody notes, while SD lacked floral traits and exhibited burnt aromas. This classification was supported by hierarchical clustering analysis (HCA) of volatile profiles and principal component analysis (PCA). Electronic nose data validated these findings, showing strong correlations between sensor responses (W5S/W2W) and key compounds like hexanal and β-ionone. This study elucidates the molecular basis of aroma-driven quality grading in Wuyi Shuixian tea, providing a scientific framework for optimizing processing techniques and enhancing quality evaluation standards. The integration of chemical profiling with sensory attributes advances precision in tea industry practices, bridging traditional grading with objective analytical metrics. Full article

The characteristic minty-like aroma of ‘Rucheng Baimaocha’ black tea (RCBT) enhances the tea’s unique flavor profile, driving high demand among consumers. The dynamic changes in key aroma compounds in minty-like RCBT were elucidated by sensory evaluation and gas chromatography olfactometry quadrupole time of flight mass spectrometry (GC × GC-O-Q-TOF-MS). The results indicated that during processing, the aroma of RCBT transitions from a fresh to floral, sweet, and minty-like aroma. Among the 189 identified volatile compounds, alcohols constitute the predominant category (over 50%), with 71 compounds identified as key differential compounds across all stages. Aroma analysis revealed that 28 compounds with odor activity values (OAV) > 1 were the primary contributors during RCBT processing. Notably, minty-like odorants in RCBT were primarily derived from the metabolic pathways of the methylerythritol phosphate (MEP) and mevalonic acid (MVA), lipid oxidation, and phenylalanine. These findings offer theoretical insights for improving unique black tea quality and optimizing processing techniques. Full article

China is the place of origin and main producer of black tea worldwide, with Dianhong (DH), Chuanhong (CH), and Keemunhong (KH) being the famous Chinese black teas. The contents of various odor components in black teas differ with their origins. However, the effects of these differences on the presentation of distinctive odor characteristics in various products remain unclear. We aimed to elucidate the odor characteristics and odor compounds of these three black teas; to this end, we performed a sensory evaluation and multivariate statistical analysis based on comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC-MS) results. The sensory evaluation revealed that the odor characteristics of DH were floral and fruity, whereas sweet and herbal-like odors were more intense in CH and QH. A total of 119 volatile compounds were detected, with alcohols, aldehydes, and esters being the main volatile compounds. Among them, 41 volatile compounds were identified with an odor activity value (OAV) of >1, and 24 of them were selected through principal component analysis, hierarchical cluster analysis, and orthogonal partial least squares discriminant analysis as marker substances to distinguish the three teas; thus, 24 volatile compounds are important odor compounds of DH, CH, and QH. Full article

The flavor profile of white tea emerges from the natural biochemical composition of its tender leaves, a delicate balance profoundly shaped by seasonal growing conditions and tea cultivars. However, the effects of harvest seasons on biochemical and volatile compounds in white teas in southwestern China have not been fully analyzed at present. This study investigated the sensory characteristics, biochemical components, and volatile compounds of ‘Sanhua1951’ spring white tea (SH-S), ‘Sanhua1951’ autumn white tea (SH-A), ‘Fudingdabai’ spring white tea (FD-S), and ‘Fudingdabai’ autumn white tea (FD-A). The results showed that the sensory quality (appearance, taste, and aroma) scores of spring tea were higher than those of autumn tea. Spring teas exhibited significantly higher epigallocatechin, soluble sugar, and amino acid levels than autumn teas (p < 0.05), whereas autumn teas contained greater contents of epicatechin gallate, catechin, caffeine, and polyphenols (p < 0.05), which were responsible for the differences in taste quality observed between samples with different harvest seasons. A total of 90 volatile compounds in four groups were identified through HS-SPME–GC–MS analysis, and spring white teas contained higher contents of and variability in volatile compounds than autumn white teas. According to the OPLS-DA model, 52 and 57 differential volatile compounds (VIP > 1, p < 0.05, and fold change ≥ 2 or ≤0.5) were identified in SH-S vs. SH-A and FD-S vs. FD-A, including (Z)-linalool oxide, (E)-linalool oxide, styrene, phenylethyl alcohol, (Z)-citral, etc. The odor active value (OAV) results indicated that 30 key differential volatile compounds (OAV > 1) were determined in four groups, among which β-ionone, 5,6-epoxy-β-ionone, linalool, and (E)-linalool oxide exhibited particularly high OAVs and contributed more pekoe aroma and floral sensory characteristics. Notably, (E)-linalool oxide, (Z)-jasmone, and δ-cadinene were identified in each cultivar. These findings suggest their potential as seasonal markers, paving the way for the development of white tea ’Sanhua1951’ and ’Fudingdabai’. Full article

Mastic gum, a plant-based resin from mastic trees, has become very popular in recent years and has been used in various food products due to its strong and positive aroma properties. In the present study, key odorant compounds of the mastic gum (MG) samples obtained from mastic gum trees (Pistacia lentiscus var. Chia) from two different countries, Türkiye (MGT) and Greece (MGG), were investigated and compared. The aroma-active compounds (AACs) were determined by aroma extract dilution analysis (AEDA) and by using gas chromatography-mass spectrometry-olfactometry (GC-MS-O). The two mastic gum samples exhibited similar aroma profiles but significant differences were observed in their concentrations. Among the aroma groups identified in both samples, monoterpenes were the most abundant group with α-pinene as the main compound followed by β-myrcene and β-pinene. On the other hand, the most dominant AAC in both samples was determined to be α-pinene (resinous, forest-like odor), followed by β-pinene (resinous, terpene-like odor), β-myrcene (pine-like, greenish odor), and linalool (floral, fruity odor), all of which had high flavor dilution (FD) values. The findings of the AEDA and sensory analysis revealed that the MGT sample contained more floral and fruity odors while the MGG sample had more resinous and pine-woody odors. Full article

The aim of this study was to investigate the effect of ultrasound treatment on the texture and flavor quality of Japonica rice to provide a basis for the development of a staple food product for the treatment of diabetes mellitus. The texture and flavor qualities of cooked rice were analyzed using a texture analyzer, rapid viscosity analyzer (RVA), and gas chromatography–mass spectrometry (GC-MS). The results showed that with increased ultrasound treatment time, the hardness and chewiness of the cooked rice gradually increased, while adhesion decreased. Additionally, the ultrasound treatment reduced various viscosity parameters of rice during the pasting process, inhibiting paste expansion and regrowth. Key aroma compounds influencing the aroma of cooked rice before and after ultrasound treatment included hexanal, heptanal, 2-pentylfuran, octanal, nonanal, trans-2-octenal, decanal, undecanal, trans-2-nonanal, trans-2-dodecenal, trans-2-decenal, trans-2,4-decadienal, 2-pentadecanone, and indole. The odor activity value (OAV) of these compounds increased significantly and were greater than one after ultrasound treatment. These compounds play a role in composing the unique aroma of cooked rice and contribute to sweet, floral, and nutty aromas. In conclusion, ultrasound treatment can be used to increase the content of resistant starch in cooked rice and has a positive effect on the flavor quality of cooked rice. Full article

Mulberry leaves contain polysaccharides, phenols, alkaloids, and other active ingredients which have medicinal and edible value. In this study, fermented mulberry leaf powder was prepared by solid-state fermentation using Pediococcus pentosaceus JC30. The effects of the fermentation on the phytochemical, flavor characteristics, phenolics, and antioxidant activity of mulberry leaves were studied. The results showed that the content of γ-aminobutyric acid in fermented mulberry leaf powder (FMLP) increased by 6.73-fold and the content of phytic acid decreased by 11.16%. Ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) analysis showed that the fermentation of Pediococcus pentosaceus JC30 altered the phenolic composition of mulberry leaves, increasing the total free phenolic content by 88.43%. In particular, the contents of free phenols such as leucocyanidin, myricetin, and quercetin increased significantly and were positively correlated with antioxidant capacity. The fermentation of Pediococcus pentosaceus JC30 significantly enhanced the scavenging ability of DPPH free radicals, hydroxyl radicals, and the total reducing ability of mulberry leaves. Gas chromatography ion mobility spectrometry (GC-IMS) analysis showed that FMLP has an intense fruity and floral aroma, while having less grassy and earthy odor. The fermentation improved the phytochemical, flavor, and nutritional value of mulberry leaves, which provides more possibilities for the development of mulberry leaf products outside the sericulture industry. Full article

Spreading, the preliminary step in the production of green tea, is crucial for achieving superior tea quality. This study investigated the effects of spreading on the sensory quality and volatile compounds in green tea under varying intensities of yellow light, employing GC-E-Nose and targeted metabolomics. A notable improvement in overall sensory quality was noted in tea samples subjected to a higher intensity of 6000 Lux, which was characterized by a delightful floral fragrance. In total, 70 volatile compounds were successfully identified, with 61 volatiles detected across all five light intensities. Moreover, 21 pivotal odorants featuring odor activity value (OAV) levels higher than one were determined, among which β-ionone, β-damascenone, linalool, (E, Z)-2,6-nonadienal, and phenylethyl alcohol exhibited particularly high OAVs. Correlation analysis indicated that phenylethyl alcohol, linalool, and citral exhibited robust positive correlations with the majority of key odorants, suggesting their vital contribution towards aroma enhancement. These findings offer novel insights into the regulation of tea aroma through the manipulation of light intensity during the processing of green tea. Full article

Spreading is the key process for ensuring green tea quality. However, the effect of blue light intensity conditions on the formation of green tea aroma and the evolution of key volatile compounds has not been assessed to date. Four tea samples treated with different light conditions (blue light intensities) were used to investigate the effect of spreading treatment on changes in the composition and content of volatile compounds. Volatile compounds in green tea samples were detected using headspace-solid phase microextraction and gas chromatography-mass spectrometry under different light conditions. Orthogonal partial least squares discriminant analysis (OPLS-DA) and relative odor activity value (rOAV) analyses were then applied to clarify the best blue light condition for forming aroma and associated compounds. The 116 volatile compounds were detected in the green tea samples, of which alcohols were the most abundant. The findings demonstrated that MBL (middle-intensity blue light; 150 μmol/(m²∙s)) treatment was the most effective condition for developing an intense and persistent fruity and floral scent compared to HBL (high-intensity blue light; 300 μmol/(m²∙s)) and LBL (low-intensity blue light; 75 μmol/(m²∙s)). This study underscores how blue light intensity conditions shape green tea aromas and offers operational insights. It also provides a theoretical basis for controlling light conditions in the process of green tea spreading Full article

Dixu tea is one of the characteristic tea germplasm resources of southeastern Yunnan, and is also a precious wild tea germplasm resource. Background: In order to further develop Dixu tea products and improve their flavor, this article studies the effects of different processing methods on the aroma quality of Dixu tea. Methods: A comprehensive analysis of the aroma quality of Diwei tea was conducted using HS-SPME combined with GC-MS and multivariate statistical analysis. A principal component analysis (PCA) was applied to process the detected volatile substances and an orthogonal partial least squares-discriminant analysis (OPLS-DA) model was established. We evaluated the contribution of major compounds in the tea aroma by calculating the odor activity value (OAV). Results: The results showed that a total of 67 compounds were identified. A total of 27 major aromatic volatile compounds (OAV > 1) were screened, and 17 key differential volatile compounds were identified in different tea samples, including octanoic acid, d-citrol, laurene, hexanal, citral, β-cyclic citral, trans-2-hexenal, γ-nonanolide, β-ionone, geranylacetone, 1,1,6-trimethyl-1,2-dihydronaphthalene, geraniol, methyl salicylate, linalool, nerolidol, and 7,11-dimethyl-3-methylene-1,6,10-dodecatriene. Combined with the OAV analysis, it is shown that a floral fragrance is a common feature of Guangnan Dixu tea varieties. In addition, white tea also has a fragrant aroma, while black tea, green tea, and bamboo tube tea are all accompanied by a fruity aroma. Conclusions: In summary, processing techniques regulate the aroma characteristics of various types of tea by changing the types and contents of volatile aroma compounds. This provides a theoretical basis for exploring and utilizing tea production resources in the future. Full article

Drying methods play a crucial role in the formation of green tea aromas. This study investigated the aroma characteristics and volatile component profiles of large-leaf green tea under hot-air drying, pan-fired drying, and sun drying. The results revealed significant differences in the sensory aroma characteristics and volatile components of the large-leaf green tea among the three drying methods. The pan-fire-dried green tea (PDGT) exhibited a distinct roasted aroma, while the hot-air-dried green tea (HDGT) and sun-dried green tea (SDGT) displayed a faint scent and lasting aroma characteristics, with the SDGT additionally featuring a noticeable sun-dried odor. A total of 48 differential volatile components were identified, among which β-Ionone, (E)-β-Ionone, 2,2,6-Trimethylcyclohexanone, Dihydroactinidiolide, BenzeneacetAldehyde, 2-Pentylfuran, 1,1,6-Trimethyl-1,2-dihydronaphthalene, δ-Cadinene, β-Myrcene, Geranylacetone, o-Cymene, 6-Methyl-5-hepten-2-one, (E)-β-Ocimene, and BenzAldehyde were identified as the primary contributors to the aroma differences among the three large-leaf green teas. Additionally, 43 differential volatile compounds were found to be significantly correlated with at least one of the aroma types (floral, sweet, green, faint scent, nutty, or roasted). The findings of this study provide a theoretical foundation for understanding the formation of aroma qualities in large-leaf green tea and offer valuable insights for improving its aromatic characteristics. Full article

Honeybee olfaction can influence foraging behavior and affect crop pollination. Odor-binding proteins play a vital role in honeybee olfactory perception. A previous study based on the antennal transcriptome of Apis mellifera ligustica in melon and tomato greenhouses revealed that AmelOBP2 is highly expressed. Therefore, we aimed to further investigate the olfactory recognition mechanism of honeybees by detecting the expression levels and binding ability of AmelOBP2 to floral volatiles of melon and tomato flowers. The results show that AmelOBP2 mRNA was highly expressed in the antennae of honeybees, and its protein expression was highest in the antennae at 20 days of age and was higher in the melon greenhouse. The binding ability of AmelOBP2 to floral volatiles of melon was stronger than that of tomato. AmelOBP2 had a stronger binding ability with aldehydes in melon floral volatiles and with terpenes and benzenes in tomato floral volatiles. After feeding with siRNA, the electroantennogram response of honeybees to E-2-hexenal, E-2-octenal, and 1-nonanal decreased markedly, confirming the role of AmelOBP2 in the recognition of melon and tomato floral volatiles. These results elucidate the molecular mechanisms underlying honeybee flower-visiting behavior and provide a theoretical reference for regulating the behavior of honeybees using plant volatiles. Full article