Search Results (760)

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

Unguentaria are ancient vessels for oils, perfumes, ointments, or balms. Glass unguentaria are typically small in size and have long narrow necks to limit the loss of precious contents through spills and evaporation. The vessels may have single or double barrels. This study includes both double and single unguentaria from unprovenanced archaeological contexts. Residues found inside the vessels may reveal the original contents. Gas chromatography-mass spectrometry (GC-MS) and direct analysis in real time-mass spectrometry (DART-MS) were used to identify organic components of the residues, while headspace solid-phase microextraction (HS-SPME) gas chromatography mass spectrometry provided a method to target specifically the volatile aroma compounds. Inorganic compounds in the unguentaria residues were identified by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). The results are consistent with a plant oil base, but few volatile perfume components could be characterized. While the collection of unguentaria may have contained perfumes, these results do not rule out the possibility of other unguents such as cosmetics. Full article

Butyriboletus roseoflavus is a rare wild edible mushroom. Yet, the relationship between its chemical composition and quality, as well as the influence of geographic origin on its flavor profile, remains unclear. In this study, ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) and headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS) were used to investigate flavor differences and influencing factors among samples from different regions. Seventeen key volatile compounds (OAV > 1) were identified, with α-pinene, styrene, octanal, 1,3,5-trithiane, and 2,4-undecadienal being the primary aroma contributors. Six characteristic taste-active compounds (TAV > 1) were detected, among which Glu, Ala, and His played dominant roles. Differential metabolites were mainly enriched in nucleotides and their derivatives, suggesting their importance in environmental adaptation and quality formation. Correlation analysis revealed that the abundance of key metabolites was closely related to geographic origin: temperature, humidity, light intensity, and CO₂ concentration mainly influenced aroma variation, while taste differences were associated with soil electrical conductivity and microclimatic changes mediated by altitude. These findings provide a comprehensive understanding of the flavor characteristics of B. roseoflavus and offer a theoretical basis for its future processing and utilization. Full article

The traditional nutritional use of sea fennel (Crithmum maritimum L.) has been rediscovered and reestablished, making this halophyte plant a prominent ingredient in coastal cuisine and a subject of interest in various scientific disciplines, including pharmacy and medicine. The first objective of this study was to identify the volatile profiles of essential oils (EOs) and hydrolates derived from the leaves, flowers, and fruits of sea fennel using gas chromatography–mass spectrometry. A total of 25 different volatiles were identified in the EOs and 63 were identified in the hydrolates. Limonene was the most abundant component in the EOs (74.85%, 74.30%, and 67.41%, respectively), while in the hydrolates, it was terpinen-4-ol in the leaves (27.8%) and the flowers (36.7%) and (Z)-carveol in the fruits (11.4%). The second objective was to investigate the biological activities of the samples. The antioxidant and choline inhibitory activities of hydrolates were generally low, with the flower hydrolate providing the inhibition of both enzymes and the leaf hydrolate with the highest antiradical activity. The cytotoxic activities of the EOs and hydrolates were also investigated. The human breast adenocarcinoma cell line MDA-MB-23 was the most sensitive against EOs from the flowers and fruits, reaching the IC₅₀ after 48 and 72 h, respectively. The leaf hydrolate exhibited cytotoxic activity after 72 h, while the flower hydrolate was effective after 48 h. The MCF-7 cell line was sensitive to the flower and fruit EOs, and the IC₅₀ was reached at all the tested periods. Overall, the results highlight sea fennel as a rich source of bioactive compounds that have significant potential for greater utilization in the nutraceutical and pharmaceutical industries. Full article

This study enhanced the odor retention of instant black tea powder by utilizing ultrasonic-assisted extraction and β-cyclodextrin embedding technology. Through single-factor tests considering variables such as the tea-to-water ratio, extraction temperature, ultrasonic extraction duration, and β-cyclodextrin addition, the optimal extraction conditions were determined. The ideal parameters were identified as follows: β-cyclodextrin was added at a rate of 7.5%, the tea-to-water ratio was 1:16, the ultrasonic extraction temperature was 52 °C, and the extraction duration was 30 min, and then the extract was processed by freeze-drying to obtain instant tea powder. Electronic nose trials revealed that the primary volatile odor compounds distinguishing the 14 groups of instant black tea soups were sulfides, terpenes, nitrogen oxides, alkanes, and aromatic compounds. HS-SPME-GC-MS analysis identified 65 effective volatile compounds, among which 11 key odor compounds, including Benzyl alcohol, Phytol, phenylethyl alcohol, 1,6,10-Dodecatrien-3-ol,3,7,11-trimethyl-,(E)-, Benzeneacetaldehyde, Undecanoic acid, ethyl ester, Dodecanoic acid, ethyl ester, Tetradecane, 2,4-Di-tert-butylphenol, 2-Pentadecanone, 6,10,14-trimethyl-, and indole, were the main contributors to the odor profile of instant black tea. The instant black tea powder produced under these conditions exhibited high quality, providing a valuable reference for further research on the production process of instant black tea powder. Full article

Eucalyptus wood particleboard (EPB), commonly used in indoor decoration, releases volatile organic compounds (VOCs) that can adversely affect indoor air quality and human health. This study systematically examined the VOC emission characteristics of EPB using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography mass spectrometry (GC-MS). A total of 65 VOCs were identified, with medium-volatility organic compounds (MVOCs) accounting for 28 compounds, low-volatility organic compounds (LVOCs) for 26, and high-volatility organic compounds (HVOCs) for 11. Terpenoids dominated the VOCs, comprising 78.46%, followed by aldehydes (10.77%) and alkanes (7.69%). Key odorant compounds (KOCs) were identified using the relative odor activity value (ROAV), with hexanal (ROAV = 100) and o-cymene (ROAV = 76.90) emerging as the most significant contributors to the overall odor profile. Thermal post-treatment at temperatures of 50–60 °C for durations of 6–12 h was found to be an effective method for reducing the residual VOCs and KOCs in the EPB, leading to a marked decrease in the peak areas of key odorants. The findings suggest several strategies for minimizing VOC emissions and eliminating residual odor, including reducing the use of miscellaneous wood materials, controlling the production of o-cymene, and employing thermal post-treatment at moderate temperatures. These measures provide a promising approach to reducing VOC and odor emissions from EPB and similar composite wood products, thereby enhancing their suitability for indoor applications. This study innovatively establishes an evaluation system for VOC emission characteristics in wood-based panels based on the ROAV. It elucidates the contribution mechanisms of key odor-active substances (e.g., hexanal and pentanal) and presents a thermal post-treatment process for source control, achieving simultaneous VOCs and odor elimination. A ROAV-guided hierarchical management strategy is proposed, providing scientific guidelines for the industrial production of high-quality particleboards with ultralow emissions (TVOC < 50 μg/m³) and minimal odor intensity (OI < Grade 3). Full article

The bagging technique is a traditional preharvest practice used in Vinalopó Bagged Table Grape production to improve fruit quality and protect clusters from environmental stress. However, its influence on grape volatile composition remains underexplored. This study analyzed the volatile profile of three grape varieties (‘Dominga’, ‘Aledo’, and ‘Doña María’) by comparing bagged and non-bagged clusters to assess the effect of bagging on aromatic compounds. Volatiles were extracted using headspace solid-phase microextraction (HS-SPME) and analyzed by gas chromatography–mass spectrometry (GC–MS). A total of 35 volatile compounds were identified and quantified, mainly aldehydes, terpenes, and alcohols. The highest concentration was found in non-bagged ‘Dominga’ grapes (57.17 mg kg⁻¹), and the lowest in bagged ‘Doña María’ grapes (16.36 mg kg⁻¹). Although total volatile content did not differ significantly between treatments, differences were observed in the relative abundance of chemical families. Bagged grapes showed higher proportions of aldehydes, such as hexanal and (E)-2-hexenal, contributing to green, fresh aromas, while non-bagged grapes exhibited more alcohols and esters, linked to fruity and overripe notes. This study offers new insights into the role of preharvest bagging in shaping grape volatile composition, contributing to a better understanding of its impact on fruit aroma and quality. Full article

The consumption of microalgae-based foods is growing due to their exceptional nutritional benefits and sustainable cultivation. However, their strong off-flavors and odors hinder their incorporation into food products. Lactic acid fermentation, a traditional method known for modifying bioactive and aromatic compounds, may address these challenges. This study aims to evaluate the impact of lactic acid fermentation on the aromatic profiles of four distinct Chlorella vulgaris biomasses, each varying in protein, carbohydrate, lipid, and pigment content. Six lactic acid bacteria (LAB) strains, Lacticaseibacillus casei, Lcb. paracasei, Lcb. rhamnosus, Lactiplantibacillus plantarum, Lactobacillus delbrueckii subsp. bulgaricus, and Leuconostoc citreum, were used for fermentation. All biomasses supported LAB growth, and their volatile profiles were analyzed via HS-SPME-GC-MS, revealing significant variability. Fermentation notably reduced concentrations of compounds responsible for off-flavors, such as aldehydes. Specifically, hexanal, associated with a green and leafy aroma, was significantly decreased. Lcb. paracasei UPCCO 2333 showed the most effective modulation of the volatile profile in Chlorella vulgaris, significantly reducing undesirable compounds, such as aldehydes, ketones, pyrazines, and terpenes, while enhancing ester production. These results highlight lactic acid fermentation as an effective method to improve the sensory characteristics of C. vulgaris biomasses, enabling their broader use in innovative, nutritionally rich food products. Full article

Embryo rice, as a product of processing rice, improves palatability and retains the nutritional characteristics of brown rice. However, the storage period of embryo rice is only 30 d at room temperature. To delay the deterioration in the quality of embryo rice during storage, this study used polyethylene terephthalate/aluminum foil/polyethylene (PET/AL/PE) to vacuum-package embryo rice, and analyzed the quality changes under 25 or 4 °C storage conditions. At the same time, volatile compound analysis and transcriptomic analysis were integrated to explore the quality deterioration mechanism of embryo rice during storage. The electronic nose results showed that the odor of embryo rice changed significantly during different storage periods (p < 0.05). A total of 72 volatile compounds were identified by Headspace–Solid-Phase Micro-Extraction–Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS), with 2-pentylfuran, naphthalene, and styrene contributing the most in the early stage, and 2-hexenal, nonanal, trans-2-nonenal, and ethanol contributing more in the later stage. Correlation analysis showed that fatty acids, malondialdehyde (MDA), lipase, and ferric-reducing antioxidant power (FRAP) were positively correlated with aldehydes and acids (p < 0.05), while catalase (CAT) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were negatively correlated (p < 0.05). This was mainly because the oxidative decomposition of lipids and the weakening of antioxidant capacity would lead to the accumulation of aldehydes. In the Mantel test analysis, color had the strongest correlation with volatile compounds, followed by taste value, and finally texture. In transcriptomic analysis, lipid synthesis and metabolism were key pathways for the storage deterioration of embryo rice, and the LOX gene played an important regulatory role. These results can provide a theoretical basis for the evaluation of quality and selection of storage method of embryo rice. Full article

Many scholars have studied Tricholoma matsutake soup, but there are relatively few studies exploring the aroma changes during its cooking process using different detection methods. The aroma of T. matsutake soup was analyzed and compared using electronic nose (E-nose) analysis, headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), and headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). A significant effect of cooking time on the overall aroma profile of T. matsutake soup was identified through E-nose analysis. By HS-GC-IMS and HS-SPME-GC-MS analysis, 51 volatile aroma compounds were detected, with alcohols and aldehydes identified as the main aroma substances. Based on the relative odor activity value (ROAV) and multivariate statistical analysis, 1-octen-3-ol, 1-octanol, methyl cinnamate, and 2-pentyl furan were determined to be the key aroma compounds in the cooking process. We observed that shorter cooking time preserved the mushroom aroma of T. matsutake soup most effectively. These findings can be utilized for the industrial production of T. matsutake soup and for optimization of its key aroma components. Full article

The strawberry is renowned for its distinctive fragrance and is regarded as one of the most popular fruits globally. This research analyzed the volatile compounds in four strawberry types grown in substrate systems, utilizing HS-GC-IMS, HS-SPME-GC-MS, and E-nose techniques. The results revealed a notable increase in the relative concentrations of alcohols, esters, and aldehydes in the strawberries. The E-nose was able to differentiate between the various strawberry varieties, but it was unable to fully identify specific aroma compounds. In contrast, the HS-GC-IMS and HS-SPME-GC-MS techniques demonstrated effectiveness in distinguishing and characterizing the different strawberry types, with OPLS-DA employed for further evaluation. By applying the variable importance in projection (VIP) method, six and seven aroma components were identified as potential biomarkers by GC-MS and GC-IMS, respectively. This study lays a scientific foundation for identifying key aromatic components in strawberries grown via substrate cultivation and offers comprehensive insights into their aromatic properties. Full article

Culinary herbs and spices are valued worldwide for their flavor, aroma, and medicinal benefits. They encompass diverse bioactive metabolites, such as polyphenols and terpenoids, which contribute to plant defense and offer anticarcinogenic, anti-inflammatory, antioxidant, and cognitive-enhancing effects. This study aimed to establish the volatile fingerprint of culinary herbs (lemon verbena, chives, basil, sage, coriander, and parsley) and spices (curcuma, nutmeg, cumin, black pepper, Jamaica pepper, and juniper berry) using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS). The predominant volatile organic metabolites (VOMs) identified were subjected to in silico molecular docking simulations of anti-Alzheimer’s (e.g., acetylcholinesterase (AChE), butyrylcholinesterase (BChE)), antioxidants (e.g., monoamine oxidase B (MAO-B), inducible nitric oxide synthase (iNOS)), and anti-inflammatory receptors (e.g., 5-lipoxygenase (5-LOX), cyclooxygenase-2 (COX-2)). The culinary herb and spice extracts were also subjected to in vitro assays to evaluate their potential as antioxidant (DPPH, ABTS, and ORAC) and anti-inflammatory (% protein denaturation) agents. A total of 121 VOMs were identified in the culinary herbs and spices, with the predominant chemical families being monoterpenoids (48.3%), sesquiterpenoids (14.0%), esters (11.9%), and carbonyl compounds (8.8%). In silico molecular docking simulations revealed that cuminaldehyde, β-caryophyllene, γ-curcumene, germacrene D, and τ-cadinol exhibited the strongest inhibitory activities against the selected receptors. Among the extracts, Jamaica pepper showed the highest antioxidant and anti-inflammatory activities, while lemon verbena exhibited the lowest ones. These findings highlight the promising potential of the studied culinary herbs and spices in the modulation of inflammatory processes related to Alzheimer’s disease. However, further investigations, particularly clinical studies, are recommended to validate these results and explore their therapeutic applications. Full article

The influence of high-pressure processing (HPP) at 200, 400, and 600 MPa on spoilage bacterial diversity, microbial load, and chemical and sensory properties of the precooked edible portion of baby clam (PC-EP) was investigated. HPP at 400 MPa for 4 min (400 MPa) significantly prolonged shelf life and sensory acceptability up to 12 days, maintaining a total viable count (TVC) below 6 log CFU/g. In contrast, the TVC of both the control (without HPP treatment) and 200 MPa-treated samples exceeded this limit by day 0 and 3, respectively. The 400 MPa-treated samples showed a reduced load of psychrophilic bacteria, Aeromonas species, and lactic acid bacteria over 12 days. Additionally, coincidentally lower total volatile base and trimethylamine levels confirmed the good quality of HPP-treated PC-EP. Based on next-generation sequencing, a significantly lower microbial diversity index was found in the 400 MPa-treated samples, and it was dominated by Carnobacterium, Lactococcus, and Psychrobacter on day 12. In contrast, the control harbored spoilage bacteria, including Lactococcus, Aeromonas, Shewanella, and Pseudomonas, which correlated with higher acetic acid and acetoin levels as confirmed by HS-SPME-GC-EI/MS. These findings demonstrated that HPP at 400 MPa for 4 min was an effective non-thermal preservation method, extending the shelf life of PC-EP by inhibiting spoilage bacteria. Full article

In recent years, numerous studies have demonstrated that non-Saccharomyces yeasts hold potential for industrial application and aroma generation during fermentation. Non-Saccharomyces wild yeasts can be important tools in the development of new products, and the objective of this work was to obtain and characterize novel yeast isolates for their ability to produce beer. Traditional fermented beverages serve as a vital source of yeast strains that can exhibit unique characteristics during the brewing process. Thus, 22 strains of Saccharomycopsis fibuligera were isolated from traditional fermented foods in this work. Subsequently, through primary and secondary screening, S. fibuligera G02 was identified as a promising candidate for beer brewing, attributed to its advantageous physiological traits and notable potential for beer production. Headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC–MS) was employed to analyze the volatile flavor substances in beer fermented using the S. fibuligera G02 strain. Chemometric analysis revealed that S. fibuligera G02 had a unique influence on beer aroma. Accordingly, isoamyl alcohol, phenyl-1-ethanol, ethyl acetate, isoamyl acetate, and 4-ethyl guaiacol (4EG) were the key aroma components of S. fibuligera G02. This work provides useful insights into the non-Saccharomyces yeasts to reference the targeted improvement of beer aroma. Full article

Sensory analysis is a fundamental tool in evaluating extra virgin olive oil (EVOO) quality, playing an essential role in both consumer markets and international competitions that recognize and promote high-quality olive oils. Among the key attributes assessed, the fruitiness descriptor—subcategorized as green or ripe—is particularly significant, especially considering that higher green fruitiness is often associated with greater prestige. However, a clear methodological approach to distinguish between green fruitiness and ripe fruitiness perceptions, particularly in their overlapping zone, is still lacking. This study aims to establish precise criteria for defining these boundaries by analyzing monovarietal EVOOs produced from nine olive varieties at three maturity stages over two consecutive harvest seasons (2021/2022 and 2022/2023). Sensory assessments were conducted by the Official Tasting Panel of Virgin Olive Oils of Catalunya, ensuring representativeness across the different fruitiness perceptions. Volatile compounds of the samples were extracted using headspace solid-phase microextraction (HS/SPME) and separated and identified via gas chromatography–mass spectrometry (GC/MS). Multivariate analysis revealed three distinct volatile profiles corresponding to different sensory perceptions. These findings suggest that incorporating an intermediate sensory attribute between green fruitiness and ripe fruitiness could improve classification accuracy in both competitions and premium markets, enhancing the appreciation and valuation of high-quality EVOOs. Full article