Metabolomics is a tool used for quantitative assessment of metabolites that has been applied extensively in the field of food science. Recently, metabolomics-based gas chromatography-mass ...spectrometry (GC/MS) is becoming a common tool for analyzing, not only volatile compounds, but also non-volatile compounds due to the development of various derivatization methods. Although several studies have reviewed the application of metabolomics in food science, this present review article specifically focuses on metabolomics research using GC/MS for analysis of non-volatile compounds such as sugars, amino acids, and organic acids. From exhaustive literature research, the application of GC/MS-based metabolomics for non-volatile compounds in food science includes discriminating food samples based on cultivars and authentication of food samples to prevent food fraud, characterizing the profile of food samples to provide a general overview of the sample, evaluating stress-response, optimizing postharvest processes based on metabolic changes, monitoring changes during growth and food processing, evaluating and predicting food quality, and evaluating food shelf-life. GC/MS-based analysis of non-volatile compounds has been proven to be extremely valuable in food science, and might open new avenues for future researchers and engineers to develop instruments or improving production process in food industry.
Metabolomics has been an evolving science with a wide range of applications in various fields. However, previous studies have rarely focused on metabolite chirality. In this study, to achieve ...metabolic profiling of chiral amino acids and related metabolites, we developed a high-throughput method using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The combination of two types of chiral columns (with binaphthyl-based crown ether and cinchona alkaloid-derived zwitterionic stationary phases) enabled the analysis of 115 chiral and non-chiral metabolites. By finely optimizing MS/MS parameters, the method allowed the highly sensitive (0.001–50 nmol/mL) and wide dynamic range detection of targeted analytes in a standard solution without derivatization. We applied the method to food samples (cheese), and successfully quantified trace levels of metabolites such as d-amino acids in samples. Additionally, we performed principal component analysis on the metabolome data and obtained unique profiles that reflected metabolite chirality. These results demonstrated the applicability and feasibility of the LC-MS/MS method as an effective tool for wide-targeted chiral metabolome analysis.
Recently, the demand for d-amino acid profiling has been drastically increasing because the significance of d-amino acid in various biological events is suggested. However, the present methodologies ...for d-amino acid profiling are still unsatisfactory. Therefore, a highly sensitive, robust, high-throughput, and user-friendly method for d-amino acid profiling must be developed. In this paper, we developed a novel method for d-amino acid profiling using a combination of a chiral column and time of flight mass spectrometry (TOFMS). To our knowledge, our approach has the best performance for d-amino acid analysis that includes the shortest analytical time (within 10 min), the highest enantioseparability without derivatization, and the largest coverage for analytical targets (more than one hundred targets including non-proteinogenic amino acids and amines). Thus, our novel profiling method will be instrumental in advancing the d-amino acid research in the future.
The goal of metabolomics analyses is a comprehensive and systematic understanding of all metabolites in biological samples. Many useful platforms have been developed to achieve this goal. Gas ...chromatography coupled to mass spectrometry (GC/MS) is a well-established analytical method in metabolomics study, and 200 to 500 peaks are routinely observed with one biological sample. However, only ~100 metabolites can be identified, and the remaining peaks are left as "unknowns".
We present an algorithm that acquires more extensive metabolite information. Pearson's product-moment correlation coefficient and the Soft Independent Modeling of Class Analogy (SIMCA) method were combined to automatically identify and annotate unknown peaks, which tend to be missed in routine studies that employ manual processing.
Our data mining system can offer a wealth of metabolite information quickly and easily, and it provides new insights, particularly into food quality evaluation and prediction.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In conventional forensic science, blood and urine have been used for drug testing. However, hair has recently attracted attention as a new source of biological information in this milieu. Drugs and ...biomolecules taken up by the hair from the capillaries of the scalp are retained in the hair without being degraded by enzymes, migrating toward the tip of the hair as the hair grows at a constant rate. As a result, drug residues are stored in the hair in chronological order. In recent years, mass spectrometry imaging (MSI) has been developed to visualize the history of drug use in hair samples, making use of this unique property. Advances in this drug testing technique are expected to create a powerful deterrent for drug abuse and doping. In this paper, we introduce the history of hair research using MSI and the evolution of instruments, matrices, and methods.
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Enzyme histochemistry facilitates enzyme activity visualization in situ; however, as it is a color-based method, molecular quantification is prohibitive. This study aimed to develop a ...semiquantitative, mass spectrometry imaging (MSI)-based enzyme histochemistry method to determine endogenous cholinesterase (ChE) activity. Using deuterium-labeled acetylcholine (ACh-d9) as a substrate to distinguish ACh-d9 and choline-d9 from endogenous acetylcholine and choline, respectively, the heterogeneous localization of de novo ChE activity was visualized using MSI, devoid of interferences from in situ factors. Furthermore, a tissue inhibitor assay involving two ChE inhibitors in the mouse brain revealed specific ChE inhibition in the corpus callosum. To the best of our knowledge, this study is the first to report a visualization method for total ChE activity in the ganglia and abdomen in Drosophila melanogaster, indicating its applicability among different animals. The present results provide novel insights into the applicability of enzyme histochemistry via MSI to the metabolism of low-molecular-weight organic compounds (i.e., “small molecules”) and semiquantitative capability, suggesting that MSI enzyme histochemistry may become a powerful tool for heterogeneous tissue studies.
Introduction
The consumption of high quality coffee such as specialty Arabica and fine Robusta coffee is increasing steadily in recent years. Development of single origin coffee is an important ...strategy to maintain coffee quality, grade and high cupping score. Indonesia is a top exporting country for Arabica coffee with high variety of specialty coffees from different origins. Despite its long standing reputation in global coffee market, very few is known about the variability among Indonesian specialty coffees.
Objectives
This study aims to observe metabolite variability among Indonesian coffees from different species and geographical origins by means of non-targeted GC/MS metabolite profiling.
Methods
Sixty-four compounds were tentatively identified from 16 green and roasted coffee beans from different species and cultivation areas in Indonesia and were subjected to principal component analysis (PCA). Ten Specialty Arabica coffee and five Fine Robusta representing all important high quality coffees of Indonesia were also analyzed independently to further classify Indonesian coffee according to their origin.
Results
PCA results of 16 green and roasted coffee beans of different species and cultivation areas showed that samples were separated along PC1 based on different roasting condition (green and roasted) with 52.9% variance and were separated along PC2 based on different species with 19.3% variance. The result from this study showed the clustering of samples based on three major cultivation areas in Indonesia (western, central, eastern part). Metabolites showing higher concentration in Sulawesi, Papua, Flores and Sumatra samples were glycerol, glucuno-1,5-lactone, gluconic acid and sorbitol. A clear distinction in galactitol and galactinol concentration between all samples from eastern part of Indonesia and western and middle part of Indonesia was also observed.
Conclusions
Our results showed that each region (western, central and eastern part of Indonesia) has signature compounds that may serve as discriminant markers for coffee authentication. This is the first report on the classification of Indonesian specialty coffee based on their metabolic profiles and can act as a basis for marker identification for routine procedures in industry.
d-Amino acids have recently attracted much attention in various research fields including medical, clinical and food industry due to their important biological functions that differ from l-amino ...acid. Most chiral amino acid separation techniques require complicated derivatization procedures in order to achieve the desirable chromatographic behavior and detectability. Thus, the aim of this research is to develop a highly sensitive analytical method for the enantioseparation of chiral amino acids without any derivatization process using liquid chromatography-tandem mass spectrometry (LC–MS/MS). By optimizing MS/MS parameters, we established a quantification method that allowed the simultaneous analysis of 18 d-amino acids with high sensitivity and reproducibility. Additionally, we applied the method to food sample (vinegar) for the validation, and successfully quantified trace levels of d-amino acids in samples. These results demonstrated the applicability and feasibility of the LC–MS/MS method as a novel, effective tool for d-amino acid measurement in various biological samples.
The ability to reduce sample volume required for gas chromatography–mass spectrometry (GC/MS) metabolome analyses is limited by the effects of blank matrices. In this study, a GC/MS metabolome ...analytical method requiring only 5 μL of plasma obtained by fingertip puncture, was developed, while minimizing the adverse effects of blank matrices. The applicability of the newly developed method was investigated using mice tail venous blood. Removing the effects of blank matrices greatly affected the detection repeatability for trace amounts. The newly developed method has higher metabolite coverage and higher sensitivity than those of the conventional method. This study is the first to demonstrate that comparable, or improved, metabolome profile data can be obtained with one-tenth the plasma volume required for the conventional method.
•A GC/MS metabolome analysis method was developed that requires 5 μL of plasma.•The new method minimized the adverse effects associated with blank matrices.•New method provides higher metabolite coverage and improved sensitivity.
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