Chemometric Analysis Research Articles

Honey Adulteration Detection via Ultraviolet–Visible Spectral Investigation Coupled with Chemometric Analysis

Honey Adulteration Detection via Ultraviolet–Visible Spectral Investigation Coupled with Chemometric Analysis

Fast DPPH antioxidant activity analysis by UHPLC-HRMS combined with chemometrics of tempeh during food processing.

Tempeh is an antioxidant-rich soybean fermentation product from Java, Indonesia. Cooking methods have an impact on the nutritional value and bioactivity of food. This study aims to investigate how the cooking process affects the metabolites and antioxidant activity in tempeh using ultra-high-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). A nontargeted UHPLC-HRMS metabolomics and chemometric analysis were used to evaluate metabolite profiles and antioxidant activity changes because of food processing in tempeh. The score plots of tempeh produced by boiling and frying methods displayed a distinct separation from raw tempeh, revealing that the cooking process altered the metabolite composition of tempeh. Due to processing, L-glutamic acid, L-pyroglutamic acid, DL-glutamine, and D-( +)-proline became the most affected metabolites on tempeh. There were 70 metabolites that showed antioxidant activity using the DPPH assay; 23 metabolites significantly differ from DPPH and control for antioxidant activity for all processing tempeh. Metabolites with significantly different antioxidant activity in raw and processed tempeh were dominated by flavonoids, vitamin E, and bioactive lipids. The DPPH antioxidant assay using UHPLC-HRMS is promising as a fast antioxidant assay by simplifying the conventional DPPH antioxidant assay. Further, it can be used to identify the name of metabolites responsible for its antioxidant activity.

In vivo assessment of topically applied silver nanoparticles on entire cornea: comprehensive FTIR study

Silver nanoparticles (AgNPs) have gained attention in medicine for their potent antibacterial, antiviral, and anti-inflammatory properties. The use of silver nanoparticles in ophthalmic solutions raises concerns regarding potential toxicity of nanoparticles to ocular tissues, such as the cornea, conjunctiva, and retina, which necessitates further toxicity assessments aiding in the development of safer ophthalmic solutions. This study investigates the impact of AgNPs on corneal tissue using ophthalmic investigations, Fourier transform infrared (FTIR) spectroscopy, and chemometric analyses. Three concentrations of AgNPs (0.48 µg/mL, 7.2 µg/mL, and 15.5 µg/mL) were topically applied twice daily for 10 days, synthesized biologically by reducing silver nitrate with almond kernels water extract. Corneas, obtained by cutting 2–3 mm below the ora serrata, were analyzed with FTIR spectroscopy and subjected to chemometric analyses. Results reveal AgNPs’ influence on constituents with OH and NH groups, affecting corneal lipids and reducing the lipid saturation index. AgNPs alter both bulk and interfacial water, leading to changes in corneal hydration thus modifying corneal physico-chemical properties. The influence extends to the water environment around proteins and lipids, releasing bound water from phospholipids and disrupting hydrogen bonding networks around proteins. In conclusion, the applied AgNPs concentrations can be linked to dry eye onset.

Combining microscale ATR-FTIR and chemometrics to interpret degradation characteristics of earlywood, latewood, and compression wood in waterlogged archaeological pine wood

Interpreting the degradation characteristics of waterlogged archaeological wood (WAW) is crucial for the conservation of wooden cultural heritage. Generally, multidisciplinary diagnostic methods, including physical, micromorphological, and chemical approaches, are employed to evaluate the preservation state of WAW. However, primarily focused on the sample level, this methodology limits the understanding of the variability in degradation from a detailed perspective. In this paper, we adopted the in-situ microscale attenuated total reflectance Fourier transform infrared (ATR-FTIR) method to investigate the degradation variability in waterlogged archaeological Masson pine (Pinus massoniana) wood excavated from the ancient Chinese shipwreck Nanhai No. 1. Specifically, spectra of earlywood (EW), latewood (LW), and compression wood (CW) were extracted and combined with chemometrics to achieve rapid classification of their degradation levels. The micromorphological features of wood cell walls in conjunction with the ratios of lignin (A1509) and carbohydrate (A1370) peak areas were used to estimate the degradation levels. Unlike recent wood, moderate degradation in CW and severe degradation in EW and LW were classified in archaeological samples. The degradation levels were effectively determined through principal component analysis (PCA) and sparse partial least squares discriminant analysis (sPLSDA). The results suggest that chemometric analysis is a promising method to discern the variable degradation levels of archaeological wood at the tissue level. The methodologies developed in this study provide detailed insights into the degradation characteristics in WAW and improve the accuracy of evaluating the preservation state.

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.

Exploring geographic variations in quinoa grains: Unveiling anti-Alzheimer activity via GC–MS, LC-QTOF-MS/MS, molecular networking, and chemometric analysis

Exploring geographic variations in quinoa grains: Unveiling anti-Alzheimer activity via GC–MS, LC-QTOF-MS/MS, molecular networking, and chemometric analysis

Comparative investigation of metabolite signatures and hypoadiposity effect between Dali tea and Yunkang tea

Dali tea (DLT) made by wild tea plant (Camellia taliensis) has been very popular in the market。However, the signature compounds and health benefits of DLT were not reported yet. To comprehensively understand metabolite signatures and potential health-function, the distinct metabolite signatures and hypoadiposity effect between DLT and Yunkang tea (YKT, made by Camellia sinensis var assamica cv. Yunkang 10) were comparative investigated. Our data found that catechins, and dimeric catechins were lower in DLT than YKT. In contrast, the levels of phenolic acid and amino acids were higher in DLT than YKT. An un-targeted metabolomics and a chemometric analysis indicated that flavonoid biosynthesis is a major pathway that distinguishes DLT from YKT. Additionally, chlorogenic acid, ellagic acid, arginine, tyrosine, and theanine were identified as characteristic metabolites of DLT. Furthermore, animal experiment showed that YKT performs better efficiency than DLT on alleviating hyperadiposity and renal damages in high-fat-diet induced obese mice.

Effect of different drying temperature settings on the color characteristics of Tencha

Color is critical factor in the commercialization of Matcha. In this study, sensory evaluation, color difference analysis, as well as targeted and non-targeted analyses were employed to investigate the impact of different drying temperature settings on the color characteristics of Tencha. The findings revealed that compared to a single drying temperature setting, a two-stage or multi-stage drying process more effectively preserved the color quality of Tencha. Specifically, a setting involving an initial period of high-temperature drying followed by low-temperature drying (samples T_6, T_7, T_10, and T_13) resulted in superior tea color quality, characterized by higher chlorophyll content and lower levels of lutein and β-carotene. Chemometric analysis identified chlorophylls and their derivatives (chlorophyll a/b, pheophytin a/b, pyropheophytin a/b) as the key factors influencing Tencha's color. These results can provide valuable insights for optimizing tea processing methods to enhance quality.

GC-MS and multivariate analysis reveal partial serum metabolome restoration by bevacizumab in a colon cancer rat model: An untargeted metabolomics investigation

Bevacizumab is an anti-angiogenic therapeutic agent that targets vascular endothelial growth factor (VEGF) and has been approved for the treatment of several types of cancer, including colon cancer. Herein, a GC-MS based metabolomics approach was employed to investigate the impact of bevacizumab on the serum metabolome of colon cancer rats. Multivariate chemometric analysis models such as PCA and PLS-DA showed a clear separation between the control, cancer and bevacizumab-treated groups, suggesting that bevacizumab administration induced significant metabolic alterations. Furthermore, pairwise comparisons between the studied groups using the OPLS-DA model in addition to univariate analysis identified several discriminatory metabolites belonged to various chemical classes including amino acids, organic acids and fatty acids that were perturbed between the studied groups. Interestingly, bevacizumab treatment was able to partially restore some of the cancer-induced metabolic disturbances, indicating its potential therapeutic efficacy via improving the tumor vasculature and nutrient delivery. Besides, pathway analysis of the differential metabolites identified key metabolic pathways affected by bevacizumab, which included valine, leucine and isoleucine metabolism, pyruvate metabolism and butanoate metabolism. However, little effects were observed on lipid metabolites such as palmitic acid and stearic acid and consequently their related metabolic pathways such as fatty acid biosynthesis metabolism suggesting that bevacizumab has more prominent effect on energy and amino acid metabolisms as compared to fatty acid metabolism in colon cancer rats. Overall, our study provided novel insights into the metabolic mechanisms underlying the therapeutic effects of bevacizumab in colon cancer rats via the use of a comprehensive GC-MS metabolomics approach.

Comparative Blood Profiling Based on ATR-FTIR Spectroscopy and Chemometrics for Differential Diagnosis of Patients with Amyotrophic Lateral Sclerosis—Pilot Study

Amyotrophic lateral sclerosis (ALS) is a motor neurodegenerative disease characterized by poor prognosis. Currently, screening and diagnostic methods for ALS remain challenging, often leading to diagnosis at an advanced stage of the disease. This delay hinders the timely initiation of therapy, negatively impacting patient well-being. Additionally, misdiagnosis with other neurodegenerative disorders that present similar profiles often occurs. Therefore, there is an urgent need for a cost-effective, rapid, and user-friendly tool capable of predicting ALS onset. In this pilot study, we demonstrate that infrared spectroscopy, coupled with chemometric analysis, can effectively identify and predict disease profiles from blood samples drawn from ALS patients. The selected predictive spectral markers, which are used in various discriminant models, achieved an AUROC sensitivity of almost 80% for distinguishing ALS patients from controls. Furthermore, the differentiation of ALS at both the initial and advanced stages from other neurodegenerative disorders showed even higher AUROC values, with sensitivities of 87% (AUROC: 0.70–0.97). These findings highlight the elevated potential of ATR-FTIR spectroscopy for routine clinical screening and early diagnosis of ALS.

In Vivo Insights: Near-Infrared Photon Sampling of Reflectance Spectra from Cranial and Extracranial Sites in Healthy Individuals and Patients with Essential Tremor

Near-infrared (NIR) spectroscopy is a powerful non-invasive technique for assessing the optical properties of human tissues, capturing spectral signatures that reflect their biochemical and structural characteristics. In this study, we investigated the use of NIR reflectance spectroscopy combined with chemometric analysis to distinguish between patients with Essential Tremor (ET) and healthy individuals. ET is a common movement disorder characterized by involuntary tremors, often making it difficult to clinically differentiate from other neurological conditions. We hypothesized that NIR spectroscopy could reveal unique optical fingerprints that differentiate ET patients from healthy controls, potentially providing an additional diagnostic tool for ET. We collected NIR reflectance spectra from both extracranial (biceps and triceps) and cranial (cerebral cortex and brainstem) sites in ET patients and healthy subjects. Using Partial Least Squares Discriminant Analysis (PLS-DA) and Partial Least Squares (PLS) regression models, we analyzed the optical properties of the tissues and identified significant wavelength peaks associated with spectral differences between the two groups. The chemometric analysis successfully classified subjects based on their spectral profiles, revealing distinct differences in optical properties between cranial and extracranial sites in ET patients compared to healthy controls. Our results suggest that NIR spectroscopy, combined with machine learning algorithms, offers a promising non-invasive method for the in vivo characterization and differentiation of tissues in ET patients.

Metabolomics based on GC-MS combined with chemometrics for geographical discrimination of garlic (Allium sativum L.)

Ensuring the geographic origin of products helps protect consumers against fraud and mislabeling. This study investigates the metabolomic profiles of garlic (Allium sativum L.) samples from Brazil and China using gas chromatography-mass spectrometry (GC-MS). Multivariate analysis Partial Least Squares Discriminant Analysis (PLS-DA) and Orthogonal PLS-DA (Ortho PLS-DA) revealed clear metabolic distinctions between the two sample groups with high classification accuracy. Brazilian garlic samples showed higher levels of sulfur compounds, such as allyl propyl sulfide, cysteine sulfonic acid, and S-carboxymethyl-L-cysteine, which contribute to its pungency and potential health benefits. Amino acids L-arginine, L-glutamic acid, and L-cysteine were also significantly increased in garlic from Brazil. In contrast, Chinese garlic exhibited higher intensities of sugars (e.g., D-fructose, D-mannose) and essential amino acids (L-tryptophan, L-valine, and L-leucine). These differences in metabolism are the result of distinct metabolic profiles. GC-MS-based untargeted metabolomic and chemometric analysis were able to differentiate the geographical origin of Brazilian and Chinese garlics and remain valuable to food authentication and quality control. Further studies are needed to confirm the biomarkers for origin verification here stated.

Ultrafast and Ultrasensitive Bacterial Detection in Biofluids: Leveraging Resazurin as a Visible and Fluorescent Spectroscopic Marker.

Here we report the application of chemometric analysis for modeling absorbance spectroscopy and fluorescence emission data from a resazurin-based assay targeting low-level bacterial detection in biofluids. Bacteria spiked samples were incubated with resazurin and absorbance and fluorescence data were collected at 30 min intervals. The absorbance data was subjected to Principal Component Analysis (PCA) and Partial Least Squares Regression (PLSR) and compared with the univariate fluorescence spectroscopy approach. The analysis demonstrated the multidimensional nature of the absorbance data, highlighting the appearance of the resorufin peak at the 2 h time point with a low bacterial inoculum of 0.01 CFU mL-1 across all the samples tested-water, urine and serum. The PLSR models supported the PCA data and exhibited strong predictive capabilities for water (RC2 = 0.937, RCV2 = 0.934), urine (RC2 = 0.899, RCV2 = 0.880) and serum (RC2 = 0.985, RCV2 = 0.967). Conversely, fluorescence is contingent upon resorufin existence, necessitating a prolonged waiting period postincubation with resazurin to verify the presence of bacteria, especially when contamination levels are low. Given the substantial global impact of bacteria-related infections, this method detects bacteria at low concentrations precisely and rapidly, improving efficiency and adaptability for point-of-care settings, promising swift diagnosis of bacterial infections, environmental monitoring, or food-quality control.

Synthetic Cathinones' Comprehensive Screening and Classification by Voltammetric and Chemometric Analyses: A Powerful Method for On-Site Forensic Applications.

The use of synthetic cathinones (SCs) has increased in recent years, posing significant public health problems due to their adverse effects and potential for fatal poisonings. The structural diversity and rapid emergence of new SC analogues create challenges for law enforcement and drug screening techniques. This work presents for the first time the electrochemical detection of SCs using differential pulse voltammetry (DPV) on a boron-doped diamond electrode (BDDE). We analyzed 15 SCs, including well-known compounds such as mephedrone, methylone, and ephylone, revealing distinct electrochemical profiles with two characteristic reduction peaks (R1 and R2). The method was optimized in Britton-Robinson buffer (0.1 mol L-1, pH 8.0) and demonstrated a high selectivity and sensitivity. Multivariate statistical methods, including principal component analysis and hierarchical cluster analysis, classified SCs into six distinct groups. The DPV optimization and analytical parameter determination, including the limit of detection (LOD), were performed for the least electroactive SC, 4'-methyl-α-pyrrolidinohexanophenone, yielding an LOD of 3.8 μmol L-1, suitable for screening street samples. Interference studies with common illicit drugs and adulterants confirmed the selectivity of the DPV-BDDE method. Preliminary identification of SCs in 46 real seized samples was successfully performed using this method with results validated by liquid chromatography-mass spectrometry (LC-MS). The method also identified three SCs not included in the original set: bupropion, benzylone, and dipentylone. The DPV-BDDE method offers a rapid, robust, and portable approach for the selective screening of SCs in forensic applications, demonstrating significant advantages over traditional colorimetric tests.

Cytotoxicity of norstictic acid derivatives, a depsidone from Ramalina anceps Nyl.

Structural modifications in lichen phenolic compounds have been one of the tools to potentiate their biological activity. In the present work, seven alkyl derivatives of norstictic acid were prepared and evaluated against eight cell lines. Norstictic acid was isolated from the lichen Ramalina anceps and the alkyl derivatives were obtained through reactions with alcohols. Cytotoxicity was evaluated against the 786-0 (kidney carcinoma), MCF7 (breast carcinoma), HT-29 (colon carcinoma), PC-03 (prostate carcinoma), HEP2 (laryngeal carcinoma), B16-F10 (murine melanoma), UACC-62 (human melanoma), and NIH/3T3 (mouse embryonic fibroblast) cell lines using the sulforhodamine B assay. Norstictic acid exhibited poor activity, while the 8'-O-n-butyl-norstictic acid and 8'-O-sec-butyl-norstictic acid derivatives showed potential activity (GI50 values of 6.37-45.0 μM and 6.8-52.40 μM, respectively) and high selectivity (selectivity index (SI) values of 13.88-98.11 and SI 11.30-87.40, respectively) against all tumor cells. The 8'-O-n-hexyl-norstictic acid showed good activity (5.96-9.53 μM) and moderate selectivity (SI 9.2-5.76) against MCF7, HT-29, PC-03, and HEP2 cells, while 8'-O-isopropyl-norstictic acid demonstrated high activity and selectivity against PC-03 cells (GI50 1.28 μM and SI 33.8), and was highly active but moderately selective against UACC, HEP2, and B16-F10 cells (GI50 6.2, 7.78, and 9.65 μM; SI 7.0, 5.5, and 4.5, respectively). Additionally, 8'-O-n-pentyl- and 8'-O-tert-butyl-norstictic acids were active and selective against PC-03 cells (GI50 8.77 and 7.60 μM; SI 6.53 and 5.0, respectively). Chemometric analysis revealed a clear relationship between all compounds and their biological activities. The insertion of a four-carbon alkyl chain (n-butyl and sec-butyl) produced potentially active compounds on all tested tumor cells.

Exploration of chemical changes in bituminous mastics induced by aging: insights from FTIR spectroscopy, DSR measurements, and machine learning

ABSTRACT The aging phenomenon in bituminous mastics leads to distinct chemical changes that affect their mechanical and rheological properties. Experimental testing like Fourier Transform Infrared (FTIR) spectroscopy and Dynamic Shear Rheometer (DSR) often require advanced post-processing to reveal underlying patterns. This research employs advanced pattern recognition algorithms and chemometric analyses to investigate aging-induced chemical changes in bituminous mastics. The study seeks to establish a rational relationship between their chemical and rheological properties. FTIR data were analyzed using Partial Least Squares Regression-Linear Discriminant Analysis (PLSR-LDA) to derive normalised Variable Importance in Projection (VIP) scores. Post-processing of PLSR-LDA results, including Pearson correlation testing and classification through data mining algorithms, identified carbonyl groups, alcohols, and carboxylic acids as key indicators of aging. Significant mineral vibrations in the Si-O band and carbonate-related vibrations were also important for differentiating various mineral compositions in the mastics. The study demonstrated that combining PLSR with CatBoost regression analysis effectively predicts rheological behaviour based on chemical composition. These findings underscore the non-linear relationship between their chemical and rheological properties and provide a framework for predicting material performance based on chemical characteristics.

Selective and highly sensitive measurement of H2O2 and organic hydroperoxides with PtNP/Poly(Brilliant Green)/SPCE

This research presents a novel electrochemical approach for the selective measurement of hydrogen peroxide and organic hydroperoxides, which is pivotal in many fields. The study details the development of an advanced sensor using a one-pot, one-step synthesis to embed platinum nanoparticles within a 3D-polymeric matrix of poly (brilliant green) on screen-printed carbon electrodes. The modified surfaces were characterized using scanning and transmission electron microscopy, Raman spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The results obtained by amperometry showed that, at 0.1 V, only H2O2 produced an electrochemical signal, while, at higher potential (0.5 V), all the hydroperoxides tested exhibited an electrochemical signal. Sensitivities obtained for H2O2 by flow injection analysis were 431 ± 3 and 465 ± 4 μC mM−1 at 0.1 and 0.5 V, respectively, with detection limits (S/N = 3) 116 and 30 nM, respectively. For organic hydroperoxides, sensitivities ranged from 22.3 to 32.6 μC mM−1 at 0.5 V, and limits of detection from 1.15 to 5.95 μM. Chemometric analysis indicated the sensor can satisfactorily measure H2O2 in the presence of the organic hydroperoxides herein analysed. The proposed sensor showed excellent properties in terms of repeatability, reproducibility and stability, with minimal interference. The reliability of the sensor was verified by measuring hydroperoxides spiked in aqueous extracts from real air quality monitoring filters. These features highlight the suitability of the sensor for hydroperoxide measurement and underscore its reliability as a practical tool for real-world applications.

Vacuum-Assisted MonoTrapTM Extraction for Volatile Organic Compounds (VOCs) Profiling from Hot Mix Asphalt.

MonoTrapTM was introduced in 2009 as a novel miniaturized configuration for sorptive sampling. The method for the characterization of volatile organic compound (VOC) emission profiles from hot mix asphalt (HMA) consisted of a two-step procedure: the analytes, initially adsorbed into the coating in no vacuum- or vacuum-assistance mode, were then analyzed following an automated thermal desorption (TD) step. We took advantage of the theoretical formulation to reach some conclusions on the relationship between the physical characteristics of the monolithic material and uptake rates. A total of 35 odor-active volatile compounds, determined by gas chromatography-mass spectrometry/olfactometry analysis, contributed as key odor compounds for HMA, consisting mainly of aldehydes, alcohols, and ketones. Chemometric analysis revealed that MonoTrapTM RGC18-TD was the better coating in terms of peak area and equilibrium time. A comparison of performance showed that Vac/no-Vac ratios increased, about an order of magnitude, as the boiling point of target analytes increased. The innovative hybrid adsorbent of silica and graphite carbon monolith technology, having a large surface area bonded with octadecylsilane, showed effective adsorption capability, especially to polar compounds.

Prediction and Visualization of Total Volatile Basic Nitrogen in Yellow Croaker (Larimichthys polyactis) Using Shortwave Infrared Hyperspectral Imaging.

In the present investigation, we have devised a hyperspectral imaging (HSI) apparatus to assess the chemical characteristics and freshness of the yellow croaker (Larimichthys polyactis) throughout its storage period. This system operates within the shortwave infrared spectrum, specifically ranging from 900 to 1700 nm. A variety of spectral pre-processing techniques, including standard normal variate (SNV), multiple scatter correction, and Savitzky-Golay (SG) derivatives, were employed to augment the predictive accuracy of total volatile basic nitrogen (TVB-N)-which serves as a critical freshness parameter. Among the assessed methodologies, SG-1 pre-processing demonstrated superior predictive accuracy (Rp2 = 0.8166). Furthermore, this investigation visualized freshness indicators as concentration images to elucidate the spatial distribution of TVB-N across the samples. These results indicate that HSI, in conjunction with chemometric analysis, constitutes an efficacious instrument for the surveillance of quality and safety in yellow croakers during its storage phase. Moreover, this methodology guarantees the freshness and safety of seafood products within the aquatic food sector.

Identification and Biotransformation of Volatile Markers During the Early Stage of Zygosaccharomyces rouxii and Zygosaccharomyces mellis Contamination in Acacia Honey.

To address the volatile markers and their biotransformation during the early stage of Zygosaccharomyces spp. contamination in acacia honey, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and chemometric analyses were used to explore the variation of volatile compounds. A total of 36 and 35 volatile compounds were identified before and after contamination of Zygosaccharomyces rouxii and Zygosaccharomyces mellis, respectively. Methyl butyrate and 2-methyl-3-pentanone could be used as volatile markers of Z. rouxii and Z. mellis-contaminated honey, which were both specific products of the yeast's own fermentation. 2,5-Dimethylbenzaldehyde was identified as a volatile marker of Z. rouxii and Z. mellis-contaminated acacia honey, and it was a specific product resulting from the interaction of yeast and acacia honey. In addition, β-damascenone could be determined as a potential volatile marker after Z. rouxii-contaminated acacia honey. Methyl 2-methylbutyrate was used as a potential volatile marker in the high-concentration groups of Z. rouxii and Z. mellis. The content ranges of methyl butyrate, 2-methyl-3-pentanone, and 2,5-dimethylbenzaldehyde in four samples were 6.62-14.59, 3.15-5.42, and 52.52-215.19 μg/mL, respectively. The variation of volatile markers during the early stage of osmotolerant yeast contamination provided a theoretical basis for the use of HS-SPME-GC-MS for the rapid detection of acacia honey deterioration while reducing economic losses.