Non-volatile Compounds Research Articles

Genus Stachys—Phytochemistry, Traditional Medicinal Uses, and Future Perspectives

The genus Stachys represents one of the most extensive genera within the subfamily Lamioideae and ranks as one of the largest genera in the Lamiaceae family. Many Stachys species are associated with a rich history in traditional medicine across various cultures, and their extracts and essential oils are rich in non-volatile and volatile compounds. Because of their complex profile of bioactive substances, Stachys members are considered to possess an extensive spectrum of therapeutic properties, including antioxidant, anti-inflammatory, analgesic, antibacterial, cytotoxic, and wound-healing effects, as well as benefits for memory enhancement, lipid profile regulation, blood glucose control, and weight management. Despite the wide distribution and chemical diversity of the genus, studies on its biological activities remain limited. The aim of this review is to summarize the most relevant data from studies on the bioactive compounds, traditional uses, and pharmacological properties of Stachys species found in databases such as Science Direct, PubMed, and Scopus. Specific keywords were used in the search strategy, including “bioactive compounds”, “Stachys”, “Lamiaceae”, “Stachys extract”, “Stachys essential oil”, “traditional uses”, “chemical composition”, “therapeutic potential”, “clinical trials”, “in vivo studies”, “in vitro studies”. The search strategy was performed according to the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Data from 171 studies were included. The manuscript highlights the drug-discovery potential of Stachys species, emphasizing their potential applications in medicine, cosmetics, dietary supplements, and the food industry. Moreover, it provides important data that could assist Stachys research programs.

Schinus terebinthifolia Raddi—Untargeted Metabolomics Approach to Investigate the Chemical Variation in Volatile and Non-Volatile Compounds

Context: Schinus terebinthifolia Raddi is used in Brazilian folk medicine due to the wound healing and antiseptic properties of its bark, and its fruit are used as a condiment. However, the aerial parts of this plant have been studied and present some bioactive compounds as well. Objectives: The aim of this study was to investigate the variation in volatile and non-volatile composition of S. terebinthifolia leaves using untargeted metabolomics. Material and Methods: The leaves of four trees were collected over one year; ethanolic extracts were analyzed by UHPLC-MS and fresh leaves were analyzed by GC-MS using HS-SPME. The data were processed using online software. Results: The results suggest seasonality interfered little with the chemical composition of leaves. On the other hand, the sex of the plant clearly determined the chemical composition of both volatile and non-volatile compounds. Discussion and conclusions: Chemical variability between plants with male and female flowers is fundamental information for the standardized use of its leaves. Compounds with important biological activities were putatively identified, confirming the potential use of S. terebinthifolia leaves as a source of bioactive compounds, reducing waste and increasing economic gains for local farmers throughout the year.

Characterization of Bioactive Phenolic Compounds Extracted from Hydro-Distillation By-Products of Spanish Lamiaceae Plants

Plants of the Lamiaceae family are widely used for the extraction of essential oils, and this industry generates a large number of solid residues as by-products, which contain non-volatile valuable compounds. The aim of this work was to identify and quantify the phenolic compounds present in these solid residues from different important Spanish species of Lamiaceae to characterize and valorize them. Forty-seven phenolic compounds were identified by HPLC-DAD-MS and quantified by HPLC-DAD. Different concentrations and types of phenolic compounds were found between the solid residues. The Rosmarinus officinalis extracts showed the highest total phenolic content due to their high phenolic terpene concentrations. The Thymus mastichina extracts were characterized by kaempferol and flavanones, and some flavones were derived from luteolin and apigenin. Finally, the sample Lavandula and Salvia lavandulifolia extracts presented the lowest content of most phenolic compounds, with the exception of some phenolic acids, such as danshensu, salvianolic acid A, and glucosides of hydroxycinnamic acids. Therefore, this work provides information on the quantification of a large number of phenolic compounds using a simple, sensitive, reproducible, and accurate methodology. In addition, the results indicate that these solid residues still contain important amounts of different polyphenols, which are antioxidants and can be used in different industries.

An Integrated Approach to Identify the Q-Markers of Banxia-Houpo Decoction Based on Nontargeted Multicomponent Profiling, Network Pharmacology, and Chemometrics.

The inherent complexity of traditional Chinese medicine (TCM) poses significant challenges in directly correlating quality evaluation with clinical efficacy. Banxia-Houpo Decoction (BHD), a classical TCM formula, has demonstrated efficacy in treating globus hystericus. However, the intricate composition of BHD, which contains both volatile and non-volatile active components, complicates efforts to ensure its consistent quality and clinical effectiveness. The aim of this study was to introduce an integrated approach that combines non-targeted multicomponent analysis, network pharmacology, and multivariate chemometrics to identify quality markers for the effective quality control of BHD. First, a nontargeted high-definition MSE method based on ultraperformance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UHPLC-QTOF-MS) was developed for the comprehensive multi-component characterization of BHD. Next, the quality markers of nonvolatile compounds in BHD were identified through network pharmacology analysis. Subsequently, volatile organic compounds (VOCs) in BHD samples were analyzed via headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS). Finally, the orthogonal partial least squares discriminant analysis (OPLS-DA) model was applied to screen for potential markers. Based on in-house library-driven automated peak annotation and comparison with 25 reference compounds, 128 components were identified for the first time. Additionally, honokiol, magnolol, magnoflorine, 6-gingerol, rosmarinic acid, and adenosine were preliminarily identified as potential quality markers for BHD through network pharmacology analysis. By employing two complementary techniques, HS-SPME-GC-MS and HS-GC-IMS, a total of 145 volatile compounds was identified in the BHD samples. Four potential differential VOCs in the BHD samples were further identified based on the variable importance in projection (VIP ≥ 1.5) using HS-GC-IMS combined with chemometric analysis. In conclusion, this study not only contributes to establishing quality standards for BHD but also offers new insights into quality assessment and identification in the development of classical formulations enriched with volatile components.

Impact of yeast selection on composition of vinegar fermented from pomace of a Finnish apple cultivar

Alcoholic beverages and vinegar products were produced using the pomace of a Finnish apple cultivar, and the influence of yeast strains on the non-volatile and volatile compound contents were studied. Apple pomace mashes were fermented with Saccharomyces cerevisiae, Torulaspora delbrueckii, and sequential inoculation with Lachancea thermotolerans and S. cerevisiae to produce alcoholic beverages. Commercial non-pasteurized vinegar was used as a starter to ferment alcoholic beverages into vinegars. Ethanol, acetic acid, sugars and organic acids were determined using GC-FID. A total of 63 volatile compounds were detected in the samples using HS-SPME-GC-MS. Alcoholic beverages fermented with the sequential inoculation had the highest total content of organic acids, and pure inoculation with T. delbrueckii resulted in the highest total content of sugars. Selection of different yeast strains did not alter the content of ethanol or acetic acid, but it significantly influenced the composition of volatile compounds in alcoholic beverages and vinegars. Compared to initial apple pomace mash, significant increases in the contents of ethyl esters (up to 4810-folds), higher alcohols (up to 24-folds) and volatile acids (up to 1853-folds) were observed in fermented products depending on the yeasts used. The main volatile compounds in vinegars prepared from S. cerevisiae fermented beverage were 2-phenylethanol, octanoic acid, and decanoic acid, from T. delbrueckii beverage 2-methylpropanoic acid and 3-methylbutanoic acid, and from sequential fermentation ethyl acetate, and ethyl 2-hydroxypropanoate. In conclusion, non-Saccharomyces yeasts have potential to produce more complex aromatic profile to fermented products derived from by-products of apple juice processing.

Correlation analysis between key volatile compounds and core functional bacterial community during Sichuan black tea processing

Microorganisms participate in the transformation of non-volatile compounds during black tea processing, while their effect on aroma remains unclear. In the present study, 132 KVCs (key volatile compounds) were identified in Sichuan black tea (SBT), of which, linalool and p-cymene were responsible for the citrus-like and sweet aroma of SBT. During the processing of SBT, Methylobacterium-Methylorubrum, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Pedobacter, Acidovorax, and Sphigomonas were the dominant bacterial genera. PCoA (principal components analysis)and Anoism (analysis of similarities) indicated that the bacterial community undergone subtle changes in various processes. Additionally, Pedobacter and Sphigomonas, core functional bacteria contributing to SBT aroma formation, act mainly by secreting enzymes related to amino acid conversion and glycoside hydrolysis. These enzymes include kynureninase, L-cysteate sulfo-lyase, homoserine dehydrogenase, serine/threonine protein phosphatase 1, and aminotransferase. Overall, these findings provide a deep insight into the potential mechanism of aroma formation under bacterial influence during SBT processing.

Assessing the impact of bacterial blends, crosslinking enzyme and storage times on volatile and non-volatile compound production in fermented pea protein emulsion gels

Pea protein is a promising ingredient for plant-based cheese production but has poor consumer acceptance due to intrinsic beany flavors. Fermentation could potentially decrease these off-flavors while also producing desirable cheese-like aromas. Pea protein emulsion gels were fermented using four different bacterial blends for 16 weeks with and without the crosslinking enzyme transglutaminase. The volatile organic compound (VOC) profiles were assessed by GC–MS and the peptide profile was measured by LC-MS/MS during storage. VOC production was mainly affected by the composition of the bacterial blends, followed by storage time. Crosslinking of the protein gel structure had minimal impact on VOC production. The peptide-level profiling revealed that crosslinking can reduce peptide size and the production of bitterness-like peptides in some blends. This study provides insights into the effect of bacterial blends, storage time, and enzymatic crosslinking on the production of volatile components and peptides related to aroma and peptide profiles for pea protein.

Exploring nonanol from Bacillus velezensis (YEBBR6) for root-knot nematode management in bananas: Integrating experimental and computational approaches

Nematode infestations pose a severe threat to global banana production, leading to substantial yield losses and economic damage. Among these, the root-knot nematode Meloidogyne incognita is particularly detrimental, causing root galls that severely impair water and nutrient uptake, leading to stunted growth, reduced fruit quality, and significant economic losses for farmers. In the face of increasing agricultural challenges, bacterial endophytes have emerged as essential tools for sustainable agriculture, offering ecofriendly solutions to enhance plant health and manage pests. The present study aims to identify and characterise biomolecules from bacterial endophyte Bacillus velezensis (YEBBR6) with potential nematicidal properties against root-knot nematode Meloidogyne incognita infecting banana. The analysis of volatile and non-volatile organic compounds (VOCs/NVOCs) from the inhibition zone during the ditrophic interaction between B. velezensis (YEBBR6) and Fusarium oxysporum f.sp. cubense (Foc) revealed the presence of several distinctive biomolecules with antifungal and antimicrobial properties. These compounds included linoelaedic acid, nonanol, acetylvaleryl, 5–hydroxyl methyl furfural, clindamycin, allobarbital, 3-thiazolidine carboxamide, azulene, aminomorpholine, procyclidine, campholic acid, 3 amino-4 hydroxy phenyl sulfone, 3–deoxy mannoic lactone, hexadecanoic acid, oleic acid, and dihydroacridine. The in-silico analysis revealed that nonanol, exhibited strong binding efficacy against M. incognita protein targets, including cytochrome C oxidase subunit 1, calreticulin, neuropeptide G-protein coupled receptor, chorismate mutase 1, venom allergen-like proteins, and β-1,4-endoglucanase. Notably, nonanol proved more effective than the commercially used nematicide carbofuran 3G. Molecular dynamics studies further supported the potential of nonanol, and its nematicidal properties were validated through in vitro and pot culture studies. Moreover, nonanol was found to induce the expression of defense-related genes, such as MAPK10, WRKY22, ascorbate peroxidase, catalase, and NADPH oxidase, in banana seedlings, thus enhancing the plant's immune response. These findings highlight the potential of nonanol, derived from B. velezensis (YEBBR6), as a potent and environmentally friendly alternative for controlling nematode infestations in banana cultivation.

Exploring the Exo-Metabolomes and Volatile and Non-Volatile Compounds of Metarhizium Carneum and Lecanicillium Uredinophilum.

Efforts are intensifying to identify bioactive microbial metabolites from biocontrol agents to manage plant pathogens in critical crops. This study examined both volatile organic compounds (VOCs) and non-volatile compounds from Metarhizium carneum and Lecanicillium uredinophilum strains for their antimicrobial effects against various phytopathogens and analyzed their exo-metabolomes. M. carneum VOCs inhibited four bacterial and eight fungal species by up to 45.45 %, while L. uredinophilum VOCs inhibited five bacterial and eight fungal species by up to 50.91 %. Additionally, n-BuOH extracts from both biocontrol agents effectively targeted three fungi and five bacteria. The exo-metabolomes of M. carneum and L. uredinophilum included 125 and 102 spectrometric features, respectively, primarily consisting of polyketides, alkaloids, lipids, organic aromatic compounds, terpenoids, and peptides. Our findings revealed a correlation between the phylogenetic relationships of M. carneum strains, their bioactivity patterns against phytopathogens, and their metabolomic profiles. Notably, some compounds detected in both fungi previously demonstrated biological activity against plant pathogens, enhancing their biocontrol potential. This study not only evidences the antimicrobial properties of diffusible compounds from M. carneum and L. uredinophilum, but also documents the antimicrobial potential of their VOCs for the first time, supporting their use in sustainable agricultural practices, reducing reliance on chemical inputs.

High Resolving Power Electrospray Ionization Ion Mobility Spectrometer Based on Fourier Deconvolution Multiplexing.

The resolving power of the drift tube ion mobility spectrometry (IMS) is mainly dependent on the drift length, the drift voltage, the pulse width of an ion gate, and the pressure inside the drift tube. Electrospray ionization (ESI)-IMS is a highly sensitive and reliable technique for the detection and analysis of nonvolatile compounds, and high resolving power is necessary to separate structurally similar compounds. To improve the analytical performance of atmospheric pressure ESI-IMS, the Fourier deconvolution (FD) multiplexing technique is investigated as an effective and convenient means to improve the resolving power as well as the signal-to-noise ratio. By reducing the equivalent ion gate opening width to 5 μs using a typical Tyndall-Powell ion shutter, a high resolving power RP up to 170 can be achieved with a drift length of 12 cm and a drift voltage of 10 kV. Rhodamine 6G (R6G), sodium dodecyl sulfate (SDS), methacycline, oxytetracycline, and ractopamine were evaluated using the FD-ESI-IMS, and mixtures with similar ion mobility can be well separated without prolonging the drift length.

Genus Zingiber: A Review on Botanical, Major Bioactivities and Genetic Diversity

Zingiberaceae is a perennial plant family that is found across the tropics, particularly in Southeast Asia from low land to hill forests. In Peninsular Malaysia, it is believed that 160 ginger species are widely distributed belonging to 18 genera. Most of the Zingiber species in Peninsular Malaysia are less investigated and less understood taxonomically, thus remaining as under-utilized crops. The description of their morphologies in parallel with phytochemicals and molecular information are crucial to provide valuable information for further discovery of potent compounds, identification of potential new sources of genetic variation, as well as to provide insight into the domestication and breeding of ginger. The majority of Zingiber species are perennial herbs with a fragrant scent, an upright stem, and a fibrous rhizome. The presence of volatile components such as monoterpenoids, sesquiterpenes, sesquiterpenoids and some non-volatile compounds like gingerols, shagaols, and zingerone have contributed to the strong scent of the ginger oils. Among the dominant components of Zingiber are α-zingiberene, geranial, neral, camphene, neral, neric acid, α-curcumene, and zerumbone. The crude extracts and essential oils of Zingiber have proven to show some biological activities such as antimicrobial, anti-bacterial, insecticidal, larvicidal, anti-cancer, anti-inflammatory, anti-ulceration, antioxidant, anti-fungal, immunomodulatory, and anti-nociceptive. Most Zingiber species are known to have 22 somatic chromosomes (2n=22) which is the lowest among genera in Zingiberaceae. This study underscores the crucial significance of breeding programs and germplasm conservation, specifically emphasizing the potential of common ginger as a prominent contributor.

Enhancing the fermentation rate and aroma compounds of kiwi wine via the addition of nitrogen during the stationary phase

Nitrogen addition is a viable strategy for preventing sluggish or stuck fermentation and enhancing aroma profiles in the winemaking industry. Herein, nitrogen, in the form of amino acids mixture or diammonium hydrogen phosphate (DAP), was added at different fermentation periods to investigate its effects on the fermentation characteristics, non-volatile compounds and aroma profiles of kiwi wines. Both the amino acids mixture and DAP shortened fermentation time by 1–2 days and balanced organic acid proportion by reducing malic acid content and increasing citric acid content. Adding DAP significantly decreased higher alcohols content, whereas higher alcohols content was remarkably increased with amino acids mixture supplementation. Furthermore, nitrogen addition during the stationary phase was most conducive to synthesizing other beneficial aromas, especially acetate esters and medium-chain fatty acid ethyl esters (MCFAEEs), and improving the perception of tropical fruity and cream aromas in kiwi wines. Partial least-squares regression (PLSR) results showed there was a tight correlation between amino acids and volatile compounds. This study provides an insight into the development of high-quality kiwi wine and should serve as the theoretical foundation to support the application of nitrogen addition in the wine industry.

<i>In vitro</i> studies on the development of microbial consortia for the management of major diseases in coconut and citrus

Microbial consortia for disease suppression involve combining multiple beneficial microorganisms to enhance their effectiveness in plant disease management. In present study, development of microbial consortia for the management of major diseases in coconut and citrus was carried out using bacteria Pseudomonas fluorescens, Pseudomonas putida (striata), Bacillus subtilis and fungi – Trichoderma reesei, T. harzianum, T. asperellum against major pathogens viz. Ganoderma lucidum, Thielaviopsis paradoxa, Phytopthora palmivora, Lasiodiplodia theobromae isolated from the coconut rhizosphere, and Fusarium solani isolated from the citrus rhizosphere. The promising fungal and bacterial antagonists were identified and studied for compatibility. Non-volatile compounds of consortia inhibited the test pathogens with an increase in concentration from 10 % to 75% with fungal consortia and bacterial consortia and also with mixed consortia which is composed of bacterial consortia + fungal consortia. Superior growth suppression was recorded with mixed consortia even at 10% concentration (59.44% to 65.83%) against the test pathogens in the ascending order of L. theobromae (59.44%) T. paradoxa (63.89%), G. lucidum (65.83%), P. palmivora (63.61%) and F. solani (62.78%). A similar trend was observed in 75% concentration where inhibition observed in the order of Thielaviopsis paradoxa (90.28%), G. lucidum (89.44%), F. solani (82.50%), L. theobromae (81.94%) and P. palmivora (81.39%). Volatile effect by bacterial consortia recorded the superior inhibition on test pathogens in the order of Ganoderma (85.28%), F. solani (75.28%), T. paradoxa (71.94%), P. palmivora (71.67%) and L. theobrome (67.50%) compared to the individual bioagents. Similarly, the fungal consortia showed the superior inhibitory effect on test pathogens in the order of G. lucidum (83.25%), P. palmivora (82.50%), L. theobromae (83.06%), F. solani (80.56%) and T. paradoxa (73.61%). Since there was no zone of inhibition between the strains, the interactions between Pseudomonas and Bacillus strains of Trichoderma spp. were compatible with one another. Neem cake recorded superior CFU population from 9.43 X 106 CFU at seven days by T. asperellum. Shelf life study on mixed consortia with bacterial + fungal bioagents in talc formulation indicated that all the bacterial and fungal CFU count recorded in 106 dilution for 90 days.

New Processes for Ionizing Nonvolatile Compounds in Mass Spectrometry: The Road of Discovery to Current State-of-the-Art.

This Perspective covers discovery and mechanistic aspects as well as initial applications of novel ionization processes for use in mass spectrometry that guided us in a series of subsequent discoveries, instrument developments, and commercialization. Vacuum matrix-assisted ionization on an intermediate pressure matrix-assisted laser desorption/ionization source without the use of a laser, high voltages, or any other added energy was simply unbelievable, at first. Individually and as a whole, the various discoveries and inventions started to paint, inter alia, an exciting new picture and outlook in mass spectrometry from which key developments grew that were at the time unimaginable, and continue to surprise us in its simplistic preeminence. We, and others, have demonstrated exceptional analytical utility. Our current research is focused on how best to understand, improve, and use these novel ionization processes through dedicated platforms and source developments. These ionization processes convert volatile and nonvolatile compounds from solid or liquid matrixes into gas-phase ions for analysis by mass spectrometry using, e.g., mass-selected fragmentation and ion mobility spectrometry to provide accurate, and sometimes improved, mass and drift time resolution. The combination of research and discoveries demonstrated multiple advantages of the new ionization processes and established the basis of the successes that lead to the Biemann Medal and this Perspective. How the new ionization processes relate to traditional ionization is also presented, as well as how these technologies can be utilized in tandem through instrument modification and implementation to increase coverage of complex materials through complementary strengths.

A simplified tutorial on charged aerosol detection: Understanding the basics, optimization, and troubleshooting

The charged aerosol detector (CAD) measures the overall charge deposited on aerosolized particles to produce a signal proportional to the mass of analyte present, which applies to compounds with or without a chromophore. A significant benefit of CAD is the ability to quantitate a wide range of non-volatile compounds in absence of their authentic standards due to uniform response factor for such analytes. CAD is also a valuable tool to help detect and/or quantitate compounds with poor or no UV absorption. These can include salts, impurities, and a variety of other types of analytes.In this tutorial, fundamental principles of CAD and its utilization, troubleshooting, and maintenance will be demonstrated to ensure proper CAD usage. Successful operation of CAD includes optimizing power function value (PFV) to allow for a broader dynamic range and improve uniformity of response. The use of an inverse gradient (admixed post-column) enables more accurate quantitation, when employing a gradient analysis method. Several troubleshooting strategies, including diagnosing inverse gradient pump organic solvent delivery and determining volume match/mismatch between the inverse gradient and system pumps, will be presented along with important aspects of operating a CAD. Lastly, ensuring reliable results involves monitoring the performance of CAD over time to understand whether it is working sufficiently or if maintenance is required.

Effects of different rootstocks on fruit quality and non-volatile flavor-related compounds of sweet cherry ‘summit’

In practical sweet cherry production, grafting onto rootstocks is a common practice to enhance environmental adaptability. Rootstocks play a crucial role in influencing scion growth and fruit quality by regulating the absorption and utilization of mineral elements. In this study, the influence of five rootstocks with or without root fertilization during the fruit color conversion period on the fruit quality of sweet cherry ‘Summit’ was observed. The physicochemical characteristics, external color characteristics, and total anthocyanin content of ‘Summit’ were significantly affected by both rootstock and fertilization, with an interaction between the two factors. The content of certain sugar components, organic acid components and phenolic acid components in ‘Summit’ were significantly affected by rootstocks and fertilization. ‘Summit’ grafted on Gisela 5 and H22 exhibited higher sugar content, while ‘Summit’ grafted on H11 and H17 exhibited higher organic and phenolic acid content.

Preserving snake fruit (Salacca zalacca) Voss) quality: Effective control of Peniophora salaccae SKRU002 with fungicides and biological agents

Peniophora salaccae (Russulales, Basidiomycota), a newly identified pathogen of Salacca zalacca, is a major cause of snake fruit rot, resulting in significant agricultural losses. This study evaluates the efficacy of chemical fungicides and biological controls against P. salaccae SKRU002, focusing on disease suppression and fruit quality preservation. Commercial fungicides (propiconazole®, prochloraz®, metalaxyl®, azoxystrobin®, thiram®) and Streptomyces philanthi strains RM-1-138 and RL-1-178 were tested. In vitro, prochloraz® (1000 μL mL−1) fully inhibited P. salaccae growth, outperforming other fungicides. Both S. philanthi strains exhibited strong antifungal activity through volatile and non-volatile compounds. Additionally, autoclaved (at 121 °C for 15 min) and diluted (1/1000) bacterial culture filtrates (BCF) from both strains achieved over 55 % inhibition of P. salaccae. In liquid culture, RM-1-138 (86.80 %) and RL-1-178 (80.86 %) demonstrated greater inhibition than metalaxyl® (9.34 %) and azoxystrobin® (56.84 %), though prochloraz® and propiconazole® remained the most effective (100 %). In vivo, untreated fruits inoculated with P. salaccae showed 100 % disease incidence, significant weight loss (13.28 %), color changes (L∗, a∗, and b∗), and reductions in total soluble solids, total phenolic content, and antioxidant activity, while titratable acidity remained unchanged. Both biological and chemical treatments effectively controlled the pathogen and preserved fruit quality. These findings highlight the potential of S. philanthi strains and fungicides in managing P. salaccae, offering promising strategies for snake fruit cultivation.

Comparison of different drying technologies for green tea: Changes in color, non-volatile and volatile compounds

Drying technology plays a pivotal role in tea processing. Herein, the differences in color, non-volatile, and volatile components of green tea under various drying methods were investigated. The results indicated that vacuum freeze-microwave increased the L* and b* values, and decreased the a* values of tea leaves. Moreover, vacuum freeze-microwave drying resulted in higher polyphenol content than the other three drying methods although there was no significant difference. A total of 43 volatile compounds were identified. Of these, 2-propanone, ethanol(D), ethanol(M), ethyl acetate(M), 2-methyl-1-butanol, and 2-methylthiophene were found to play an important role in the above discrimination (VIP >1.5). Dry extraction showed a higher content of volatile components than wet extraction. Regardless of the extraction conditions, vacuum freeze-microwave drying exhibited a stronger signal intensity and more volatile components than other drying methods. This study provides a reference for analyzing the quality differences of green tea by different drying methods.

Flowering in aged white tea: Recovering umami taste and amplifying of stale aroma

Throughout the natural aging process from new to aged white tea, the flavor evolves into a ‘stale flavor’, despite the initial umami diminishes. The flowering process, inoculation of Eurotium cristatum to white tea, improves the flavor. The impact on sensory qualities and underlying chemical basis of flowering in aged white tea warrant investigation. Sensory analysis, non-targeted metabolomics and volatilomics together deciphered flavor modifications of flowering in aged white tea from different aging years (FAWTs). Findings indicate the flowering process can recover the umami of aged white tea, enhancing the ‘stale flavor’. These changes primarily stem from oxidations of catechins and free amino acids, enrichments of flavonols and soluble sugars, and 16 pivotal aroma compounds from degradations of lipids and glycosides. Additionally, 15 volatile and 39 non-volatile compounds were identified as potential biomarkers for FAWTs. These findings offer a viable strategy to improving the quality of aged white tea.

Optimization of serum samples derivatization process by I-Optimal Split-plot design of experiments for GC–MS metabolomics of inflammatory neuropathies

The derivatization process is critical in gas chromatography coupled to mass spectrometry-based untargeted metabolomics. This process aims to increase common non-volatile compounds’ vapor pressure and thermal stability by two sequential steps: methoximation and silylation. Up to now, there are no standardized conditions for performing these reactions. In this study, we simultaneously optimized these procedures using an I-Optimal Split-plot design in serum samples of healthy individuals. The resultant two-factor interaction model performed well with R2 > 0.90 and R2-adjusted > 0.70 in the statistical analysis. The results revealed interactions between methoximation and silylation conditions. The optimized conditions were applied for the GC–MS untargeted metabolomics analysis of serum samples of patients with inflammatory neuropathies and healthy controls. The orthogonal partial least square discriminant analysis with satisfactory cross-validation results (R2 = 0.744, Q2 = 0.557) determined 32 metabolites with VIP score > 1. Short- and long-chain organic acids, fatty acids, and carbohydrates were annotated as potential discriminative molecular markers.