Volatile Compounds Research Articles

Differentiation of black tea according to country of origin using the μ-CTE/TD/GC-MS method combined with decision tree-optimizable neural network analysis.

Accurate discrimination of the country of origin of teas is critical to determine their actual commercial value, to meet consumer preferences, and to ensure compliance with labeling regulations. Therefore, in this study, we developed a new approach to accurately discriminate the country of origin of teas in the Turkish market. A thermal desorption/gas chromatographic-mass spectrometric (TD/GC-MS) method combined with optimizable neural networks (ONN) was developed to analyze the volatile organic compounds (VOCs) of tea samples subjected to infusion or grinding pretreatments. Prior to GC-MS analysis, the conventional thermal desorption method was applied to VOCs in the powdered teas, while VOCs in the infused teas were adsorbed on Tenax-TA sorbent tubes attached to a micro-chamber/thermal extractor (μ-CTE) and then thermally desorbed. Using a feature selection technique, a total of 11 VOCs from infused tea samples, 21 VOCs from ground tea samples, and 18 VOCs from both groups were identified as specific VOCs that critically affect the classification of the teas. As a result of ONN classification of selected VOCs from only ground tea samples and infused tea samples, 95.51% and 96.7% accuracy was obtained, respectively, while 100% classification accuracy was achieved by ONN classification of VOCs from both sample groups. The results showed that different pretreatments applied to Turkish and Ceylon teas caused the release of different volatile compounds, resulting in more specific VOC profiles. In addition, the developed μ-CTE/TD/GC-MS method allowed a more accurate classification of the black tea samples than the TD/GC-MS system alone. © 2025 Society of Chemical Industry.

Exploring the Potential of Artemisia Annua for Therapeutic Uses in Heated Tobacco Devices

ABSTRACT Artemisia annua (A. annua) herb is renowned for its potent antimalarial and broader biological activities. This study aims to explore the potential of A. annua for adding therapeutic compounds to low-temperature heated, tobacco-related products. The volatile compounds were released at four different temperatures (100°C to 325°C) and were analyzed using a Thermal Separation Probe (TSP) coupled with GC-MS. A diverse array of compounds was found, with up to 20 different terpenes identified at certain temperatures. Common terpenes found in dry and fresh tissue included Camphene, β-Sabinene, Eucalyptol, y-Terpinene, Neophytadiene, and Deoxyartemisinin. The potential use of A. annua in low-heated tobacco devices for therapeutic advantage is thus considered highly plausible.

Bioactive potential of Origanum heracleoticum L. essential oil: Chemical composition and its antimicrobial and anticancer properties

Oregano (Origanum heracleoticum L.) is a widely consumed aromatic spice, recognized as a medicinal plant due to its diverse biological and pharmaceutical properties. Essential oils (EOs) exhibit remarkable biological activities, primarily attributed to their high concentrations of volatile aromatic compounds. This study aimed to determine the chemical composition of Bulgarian oregano essential oil (OEO) and evaluate its biological activities, including anticancer, antimicrobial, anti-biofilm, and anti-quorum sensing properties. Chemical analysis revealed that carvacrol (76.90%) and p-cymene (12.84%) were the predominant components of OEO. The MTT assay demonstrated that OEO significantly reduced the viability of human lung adenocarcinoma epithelial cells (A549), human hepatocellular carcinoma cells (HepG2), and human breast adenocarcinoma cells (MDA-MB-231) at all tested concentrations (3.9-1000 μg/mL), while exhibiting considerably lower toxicity towards healthy mouse fibroblast cells (L929). Among the tested cancer cell lines, A549 cells were the most sensitive to OEO, with IC50 values indicating greater cytotoxicity towards A549 and MDA-MB-231 cells at lower concentrations. The antimicrobial, anti-biofilm, and anti-quorum sensing (anti-violacein) activities of OEO were assessed against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa PA01, P. aeruginosa ATCC 27853, Candida albicans ATCC 10231, and Chromobacterium violaceum ATCC 12472. The results revealed that OEO exhibits potent antimicrobial and anti-biofilm activities against a range of microorganisms.

Effect of Boiling Time on the Color, Water, Protein Secondary Structure, and Volatile Compounds of Beef

The influence of boiling time on the persistent changes in the surface color, water content and distribution, protein secondary structure, and the concentration of volatile compounds in beef were studied, in order to obtain quality short-term boiled beef slices. The results show that the water content of beef samples significantly decreased and migration occurred between the high-freedom water and the low-freedom water. On average, boiling for 1 min was a key point in the changes of color parameters (L*, a*, b*, w, ΔE, and BI) and partial protein secondary structure because of the change in the ambient temperature around beef. In six samples, 29 volatile compounds were confirmed by GC–MS, and 13 compounds were regarded as the potential key volatile compounds, including 1-heptanol, 1-octen-3-ol, octanal, hexanal, decanal, heptanal, nonanal, (E, E)-2,4-decadienal, (E, E)-2,4-nonadienal, dodecanal, (E)-2-undecenal, 2,3-octanedione, and 2-pentylfuran. The color, water, and protein secondary structure were closely correlated with some potential key volatile compounds. The results could be used to guide the consumers to better grasp the quality of hot-pot meat during gatherings and have a comfortable consumer experience.

Wearable facemask-attached disposable printed sensor arrays for point-of-need monitoring of ammonia in breath

Abstract Blood sampling, despite its historical significance in clinical diagnostics, poses challenges such as invasiveness, infection risks, and limited temporal fidelity for continuous monitoring. In contrast, exhaled breath offers a non-invasive, pain-free, and continuous sampling method, carrying biochemical information through volatile compounds like ammonia (NH3). NH3 in exhaled breath, influenced by kidney function, emerges as a promising biomarker for renal health assessment, particularly in resource-limited settings lacking extensive healthcare infrastructure. Current analytical methods for breath ammonia, though effective, often face practical limitations. In this work, we introduce a low-cost, internet-connected, paper-based wearable device for measuring exhaled ammonia, designed for early detection of kidney dysfunction at the point-of-need. The device, which attaches to disposable facemasks, utilizes an array of disposable paper-based sensors to detect NH3 with the readout being changes in electrical impedance that correlate with the concentration of ammonia. The sensor array is housed in a biodegradable plastic enclosure to mitigate high relative humidity (RH) issues in breath analysis. We validated our technology using a laboratory setup and human subjects who consumed ammonium chloride-containing candy to simulate elevated breath ammonia. Our wearable sensor offers a promising solution for rapid, point-of-need kidney dysfunction screening, particularly valuable in resource-limited settings. This approach has potential applications beyond kidney health monitoring, including chemical industry safety and environmental sensing, paving the way for accessible, continuous health monitoring.

Chitosan/alginate bilayer film enriched with cinnamon oil nanoemulsion: characterization, volatile compound release, and antimicrobial effects

Chitosan/alginate bilayer film enriched with cinnamon oil nanoemulsion: characterization, volatile compound release, and antimicrobial effects

Phytochemistry and Antiproliferative Potential of a Naturalized Plant in Jordan: Lavandula stoechas.

Cancer remains a leading cause of mortality, and medicinal plants offer potential anticancer agents due to their biological activities and minimal side effects. Lavandula stoechas L., a Mediterranean species, shows significant pharmacological potential. This study evaluated the composition, antioxidant, and antiproliferative properties of L. stoechas aqueous, methanol (MeOH), ethanol (EtOH), ethyl acetate, and chloroform extracts from a naturalized plant in Jordan. The aroma profile and composition of the hydro-distilled essential oil were also determined. Gas chromatography (GC) and GC-mass spectrometry (GC-MS) analysis identified fenchone, camphor, α-pinene and borneol as major constituents, with solid-phase microextraction revealing fenchone and α-thujene as dominant volatile compounds. Phytochemical analysis showed the EtOH extract had the highest total phenolic content (147.60 ± 31.80mg/g) and total flavonoid content (84.56 ± 4.33mg/g), while the MeOH extract exhibited the strongest antioxidant activity (409.83 ± 3.13µM TE/g). The EtOH extract displayed cytotoxic activity with IC50 values ranging from 22.79 to 94.06µg/mL against various cancer cell lines. Liquid chromatography-MS analysis identified rosmarinic acid as the most abundant compound (28.71%), which may contribute to the biological activity. This study highlights the potent antioxidant and antiproliferative properties of L. stoechas, especially the EtOH extract.

Morphological Traits and Biochemical and Volatile Compound Composition along with Gene Expression Profiling in Chrysanthemum morifolium Ramat. Grown under Soil and Soil-Less Conditions

Morphological Traits and Biochemical and Volatile Compound Composition along with Gene Expression Profiling in <i>Chrysanthemum morifolium</i> Ramat. Grown under Soil and Soil-Less Conditions

Wasps Beyond Bees: Crop Species of Spondias (Anacardiaceae) Vary in Floral Scent and Attract Different Pollinator Taxa

ABSTRACTSpondias species are increasingly valued for their fruit production, which relies heavily on insect pollination. The flowers of these species are generalised, attracting a diverse array of insect visitors, including bees, beetles, flies, wasps and butterflies. This study provides the first comprehensive analysis of floral scents emitted by three Spondias crop species—Spondias mombin (cajá), S. purpurea (siriguela) and S. tuberosa (umbu) and explores the potential relationships between floral cues and pollinator spectra. We examine the spectrum of floral visitors across these species from both literature and original field observations. Our results reveal significant interspecific differences in both the number and quantity of volatile compounds released, as well as in the relative composition of these scents. Cajá flowers were dominated by (E)‐β‐ocimene, α‐ and β‐pinene, methyl benzoate and benzyl alcohol, whereas siriguela flowers primarily emitted (E)‐β‐caryophyllene, (E)‐4,8‐dimethyl‐1,3,7‐nonatriene, α‐pinene, hexyl butyrate, methoxybenzene and 4‐methylanisol. Umbu flowers predominantly emitted linalool and its derivatives, and (Z)‐3‐hexenyl butyrate. The floral visitor composition varied between species. Bees, particularly from the Meliponini tribe, were the main visitors of cajá (70%), whereas siriguela attracted primarily wasps (80%), especially from the Epiponini tribe. Umbu flowers attracted in similar proportions both wasps (38%) and bees (32%). These findings highlight the importance of a broad range of insect pollinators in Spondias species, particularly the role of non‐bee pollinators like social wasps in the pollination of siriguela and umbu. We propose that variations in floral scent profiles and visual cues among these species are key factors in shaping their specific pollinator communities. This underscores the critical role of diverse insect pollinators in maintaining ecosystem services, reinforcing the need to preserve and support their populations.

Active Packaging Incorporating Cryogels Loaded with Pink Pepper Essential Oil (Schinus terebinthifolius Raddi) for Strawberry Preservation

This study evaluated the efficacy of active packaging containing albumin (ALB) and pectin (PEC) cryogels loaded with pink pepper essential oil in preserving strawberries during 7 days of storage at 4 °C. The cryogels were prepared in different ratios (ALB:PEC 50:50 and 30:70) and applied in sachets within the strawberry packaging, varying the amounts from 0.4 g to 1.0 g. Analyses included the evaluation of mass loss, soluble solids, pH, titratable acidity, color, firmness, anthocyanin content, volatile compound composition and release from the essential oil (GC-FID and GC-MS), and microbiological analyses. Results showed that the cryogels maintained the stability of soluble solids and pH, and did not significantly affect the color or anthocyanin content. Strawberry firmness was influenced by the amount of cryogel, with 0.4 g of the ALB:PEC 30:70 cryogel’s best-preserving texture. A GC-MS analysis identified monoterpenes (α-pinene, 3-carene, and D-limonene) and sesquiterpenes (caryophyllene and germacrene D) as the major volatile compounds of the essential oil, with a controlled release over time. Cryogels, especially ALB:PEC 30:70, reduced the count of mesophilic aerobic bacteria (1 g) and yeasts and molds (0.4 g). This formulation extends shelf life and preserves the quality of strawberries through controlled antimicrobial release and firmness preservation.

Metabolomic Profiling of Pogostemon cablin Reveals Disruption of Secondary Metabolite Biosynthesis Induced by Corynespora cassiicola Infection

Pogostemon cablin (patchouli) is an economically important aromatic plant widely used in the fragrance and pharmaceutical industries. This study investigates the effects of Corynespora leaf spot disease (CLSD) on the metabolic profiles and patchouli alcohol content of patchouli leaves. Utilizing gas chromatography-mass spectrometry (GC-MS), real-time PCR (qPCR), and comprehensive non-targeted metabolomic analyses (HS-SPME-GC-MS and LC-MS/MS), we compared diseased (LD-TJ) and healthy (CK) leaves. Results revealed a significant 51% reduction in patchouli alcohol content in CLSD-infected leaves, which was correlated with a 94% decrease in expression of the patchoulol synthase (PTS)-encoding gene (p &lt; 0.01) and a 79% reduction in farnesyl pyrophosphate synthase (FPPS)-encoding gene expression (p &lt; 0.05), both critical for terpenoid biosynthesis. Metabolomic analyses identified extensive disruptions in both volatile and non-volatile compounds, with the majority of differential abundance metabolites (DAMs) being downregulated. Key metabolic pathways, including beta-alanine metabolism and nicotinate/nicotinamide metabolism, were notably affected, indicating broader metabolic instability. Additionally, crucial transcription factors involved in terpenoid biosynthesis were significantly downregulated, indicating a potential mechanism by which C. cassiicola may compromise patchouli quality through modulation of host metabolic processes. These findings underscore the urgent need to develop disease-resistant P. cablin cultivars through genetic and metabolic engineering to enhance the sustainability and productivity of this valuable industrial crop.

Genome-wide identification and gene expression pattern analysis of the carotenoid cleavage oxygenase gene family in Fagopyrum tataricum

BackgroundCarotenoid cleavage oxygenases (CCOs) convert carotenoids into volatile aromatic compounds implicated in plant growth and development. They affect the synthesis of hormones, including abscisic acid (ABA) and strigolactone (SL). However, the CCO family in Tartary buckwheat remains unelucidated.ResultsWe identified the FtCCO gene family based on Tartary buckwheat genomic data and analyzed the biological function of the FtCCO genes using bioinformatics methods and the expression pattern of the gene using fluorescence quantitative PCR. Three pairs of fragment duplication genes were found in FtCCOs, and the motifs were highly conserved within the same subfamily. FtCCO genes are closely related to the dicotyledonous Arabidopsis thaliana, which has the highest number of co-linear genes. The qRT-PCR showed that among the tissue-specific expression patterns of Tartary buckwheat CCO genes, the expression of the FtCCOs was higher in the leaves. In Tartary buckwheat grain development, the relative expression of most FtCCOs was higher at the later stage. The relative expression of many genes was higher in the stems under cold, dark, NaCl, and abiotic stress conditions. However, under the hormone and plant growth regulator treatments, the expression of the nine FtCCOs was relatively low in the stems. Notably, the relative expression of FtNCED4 was extremely high under abiotic stress and hormone induction, indicating that FtNCED4 may be involved in the growth and development of Tartary buckwheat.SummaryIn this study, the FtCCO family genes of Tartary buckwheat were identified at the genome-wide level, and the gene expression pattern of the FtCCO gene family in different tissues or treatments was determined. This study provides a theoretical basis for further analysis of the functions of theFtCCO family, which is of great significance for the mining of resistance genes and trait improvement.

Insecticidal and fungicidal potential of Nocardiopsis sp. ICDN5, an actinomycete isolated from Solanum tuberosum rhizosphere

ABSTRACT Twenty-four actinomycetes were obtained from the rhizosphere of Solanum tuberosum plants affected by black cutworm (Agrotis ipsilon) infestation. Phenotypic and genotypic analyses identified the most bioactive strain as Nocardiopsis sp. ICDN5. This strain effectively utilised various food processing wastes as production media, with lobster shell medium yielding the highest enzymatic activities: protease (678.56 ± 8.23 U/gds), chitinase (489.40 ± 4.91 U/gds), lipase (192.84 ± 5.97 U/gds), and cellulase (219.15 ± 2.61 U/gds). The lobster shell-derived extract of Nocardiopsis sp. ICDN5 caused 98.00 ± 3.50% mortality and 19.18 ± 1.67% deformities in 2nd instar larvae of A. ipsilon at a dose 50 µg/mL, extending their development duration by 2.05-fold. When larvae fed on castor leaves soaked in the extract (50 µg/mL), pupal mortality increased to 64.33 ± 3.50%, development duration extended to 24.72 ± 1.54 days, malformations increased 12.50-fold, and larval weight decreased from 408.25 to 286.90 mg. Additionally, the extract significantly reduced adult emergence, fecundity, and hatchability to 9.85 ± 1.39%, 260.94 ± 9.15 eggs/female, and 34.42 ± 2.58%, respectively. Adult malformations increased to 25.90 ± 1.19%. The ICDN5 extract also demonstrated strong antifungal activity against various phytopathogens, with MIC values ranging from 6.42 ± 0.69 to 16.25 ± 1.53 µg/mL. Gas chromatography-mass spectrometry analysis of the ICDN5 extract identified 33 volatile bioactive compounds. The Nocardiopsis sp. ICDN5 strain exhibits potent biological control properties, positioning it as a promising tool for managing agricultural pests, and phytopathogenic fungi.

Increasing the Bioactive Compound Content of Olive Oil by Acidification of Olive Paste

This study investigated the impact of acidification on olive paste to enhance the extraction of olive oil enriched in bioactive phenolic compounds, aiming to develop a novel functional food. Recognizing that acidic pH promotes the activity of β-glucosidase responsible for oleuropein and ligstroside hydrolysis, food-grade organic acids—citric, ascorbic, and acetic acid—were added prior to malaxation to improve the bioactive compound content in the resulting oils. A randomized experimental design was employed, using three different doses of each acid (1, 2, and 4%) with three replicates per dose, alongside control trials without acid addition. Acidification did not affect olive oil extraction efficiency or alter quality parameters for extra virgin olive oils. Treatment with 1% ascorbic acid significantly increased phenolic compound content by 37% compared to controls. Secoiridoids comprised 79.4% of the total phenolic content, with oleacein as the predominant compound (237.58 ± 9.18 mg/kg), representing over 50% of the total. This increased oleacein concentration led to up to a 67% enhancement in antioxidant capacity (428.63 ± 31.57 mg Trolox/kg) compared to controls. The antioxidant capacities of 3,4-DHPEA, 3,4-DHPEA-EDA, and 3,4-DHPEA-EA were determined to be 12.05, 5.80, and 4.91 µmol TE/mg, respectively. Furthermore, the 1% ascorbic acid treatment enhanced volatile compounds associated with the lipoxygenase (LOX) pathway while reducing ethanol levels.

Influence of Selected Technological Conditions on the Flavour Stability of Unpasteurised Top-Fermented Craft Beer

Abstract Craft beers are usually unpasteurised and unfiltered, causing a different ageing behaviour compared to pasteurised and filtered beers. In this work, the influence of microfiltration, storage temperature, and fresh yeast addition for refermentation on the flavour stability of a top-fermented beer was studied. The determination of the main quality parameters (e.g. extract, haze, foam, pH) and volatile compounds was performed. Also, a trained panel evaluated the sensory profile of the beers. A statistical data (analysis of variance and PCA) processing approach was used to better understand how different treatments interact with the stability of an unpasteurised beer. The main quality parameters were not influenced by the different storage conditions. Microfiltration at 0.45 µm led to decreased head retention and flavour stability in all beers. In fact, oxidation and stale notes were detected only in the microfiltered beers. About volatile compounds, the aldehydes content decreased during storage for all the samples. Furthermore, there were significant differences between cold-stored and room-stored beer after 6 months in terms of aroma and flavour, especially for the hop character. This study highlighted the interesting flavour stability of unpasteurised beer, where yeast acts as a natural stabiliser during refermentation and storage. The results confirmed that cold storage (4 ± 1 °C) is the best option for beer flavour stability.

An insight into specific flavor sensation in fermented milk: Linalool and mushroom alcohol.

Flavor perception plays a decisive role in consumer choice of dairy products. That confer overall flavor formation, far less is known about the critical flavor compound of the specific sensory, particularly for fermentation aroma and off-flavor perception. Here in fine details, we resolved the volatile flavor compounds in dairy products by Lactobacillus casei or Lactobacillus bulgaricus with prolonged fermentation process using the headspace-solid phase micro-extraction (HS-SPME) and gas chromatography mass spectrometry (GC-MS), and 49 and 47 volatile flavor compounds were identified, respectively. Chemometrics combined with Odor Activity Value calculations identified 7 key flavor components (OAV > 1). Correlations between sensory attributes and flavor components were then investigated and market validation revealed the role of 2 compounds, linalool and shiitake alcohol, in conferring fermentation aroma and off-flavor perception, respectively. Overall, these results provide a potential target for the detection and development of high-quality dairy products and provide an example for the exploration of specific sensory flavor compounds in the food industry.

Effects of quantitative marinating on meat quality, biogenic amines, and flavor compounds in crayfish meat

Stewing is a traditional processing method, commonly used for crayfish meat (Procambarus clarkii). In this study, we used a novel method called quantitative marinating (QM) to reduce industrial waste during crayfish meat processing. The taste, flavor, and aroma of crayfish meat processed by boiling (CON), stewing (SG), and QM were investigated. The results showed that crayfish meat in both SG and QM had higher L* and b* values (P &amp;lt; 0.05). Crayfish meat subjected to QM exhibited significantly greater hardness, gumminess, and chewiness than SG (P &amp;lt; 0.05), which was associated with tightly packed muscle fibers, as observed via scanning electron microscopy. Both QM and SG exhibited lower bitterness and astringency compared with CON, as tested by electronic tongue. A total of 25 types of FAAs content showed significant changes in QM and SG (P &amp;lt; 0.05), with the umami amino acids and total amino acids in QM increased by 19.47 and 52.97%, respectively, compared with SG. The results of flavor 5′-nucleotides showed that GMP, AMP, and IMP in QM increased by 72.87, 48.78 and 51.98% compared with SG, respectively (P &amp;lt; 0.05). Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) identified 31 compounds, with QM having more volatile compounds such as anethole, linalool, and 1-octanol than SG. The levels of biogenic amines of tryptamine, phenethylamine, and histamine in QM decreased significantly compared with SG (P &amp;lt; 0.05). In conclusion, QM significantly improved the meat color, texture profile and taste-related qualities of crayfish meat while reducing the biogenic amines in crayfish meat.

Aromatic Volatile Substances in Different Types of Guangnan Dixu Tea Based on HS-SPME-GC-MS Odor Activity Value

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 &gt; 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.

Effect of Blue Light Intensity During Spreading on the Aroma of Green Tea

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

Evaluation of the Impact of Fermentation Conditions, Scale Up and Stirring on Physicochemical Parameters, Antioxidant Capacity and Volatile Compounds of Green Tea Kombucha

This study evaluated the influence of tea, sucrose, and inoculum concentrations on green tea kombucha’s physicochemical properties and antioxidant capacity to optimize its production. The highest total phenolic content (98.61 mg GAE/100 mL) and radical scavenging activity for ABTS (9647.14 μmol/mL) and DPPH (6640.00 μmol/mL) were observed with 8 g/L of tea, 80 g/L of sucrose, and 30% inoculum. Principal Component Analysis highlighted inoculum as the key factor influencing these parameters. Following this, fermentation was scaled up in 6.5 L bioreactors operating under static and stirred conditions. Monitoring physicochemical properties, antioxidant capacity, and volatile compounds revealed the impact of agitation on fermentation, with the kombucha obtained by static cultivation presenting higher biological activity. Eleven volatile compounds were identified, including carboxylic acids, terpenes, esters, alcohols, and phenols. Notably, α-terpinolene, dodecanoic acid, and 2,4-di-tert-butylphenol, found in kombucha, exhibit antioxidant properties linked to health benefits. Differences in volatile compound profiles were observed between static and stirred processes. This study concluded that kombucha maintains its physicochemical characteristics and bioactivity during scale-up, contributing to a better understanding of large-scale production. It also suggests stirred cultivation as an alternative for kombucha production.