Studying the effect of storage conditions on the metabolite content of red wine using HILIC LC-MS based metabolomics

Advanced LC-IMS-MS Protocol for Holistic Metabolite Analysis in Wine and Grape Samples

The final aim of metabolomics is the comprehensive and holistic study of the metabolome in biological samples. Therefore, the use of instruments that enable the analysis of metabolites belonging to various chemical classes in a wide range of concentrations is essential, without compromising on robustness, resolution, sensitivity, specificity, and metabolite annotation. These characteristics are crucial for the analysis of very complex samples, such as wine, whose metabolome is the result of the sum of metabolites derived from grapes, yeast(s), bacteria(s), and chemical or physical modification during winemaking. In recent years, a big advantage, in this direction, was the hardware developments on hyphenated instruments that enable the integration of liquid chromatography (LC), ion mobility spectrometry (IMS), and mass spectrometry (MS). This chapter describes an LC-IMS-MS protocol for the analysis of wine and grape samples as well as the use of IMS data in metabolite annotation.

A metabolomics approach reveals metabolic disturbance of human cholangiocarcinoma cells after parthenolide treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Tanacetum parthenium (L.) Schultz-Bip, commonly known as feverfew, has been traditionally used to treat fever, migraines, rheumatoid arthritis, and cancer. Parthenolide (PTL), the main bioactive ingredient isolated from the shoots of feverfew, is a sesquiterpene lactone with anti-inflammatory and antitumor properties. Previous studies showed that PTL exerts anticancer activity in various cancers, including hepatoma, cholangiocarcinoma, acute myeloid leukemia, breast, prostate, and colorectal cancer. However, the metabolic mechanism underlying the anticancer effect of PTL remains poorly understood.

AIM OF THE STUDY

To explore the anticancer activity and underlying mechanism of PTL in human cholangiocarcinoma cells.

MATERIAL AND METHODS

In this investigation, the effects and mechanisms of PTL on human cholangiocarcinoma cells were investigated via a liquid chromatography/mass spectrometry (LC/MS)-based metabolomics approach. First, cell proliferation and apoptosis were evaluated using cell counting kit-8 (CCK-8), flow cytometry analysis, and western blotting. Then, LC/MS-based metabolic profiling along with orthogonal partial least-squares discriminant analysis (OPLS-DA) has been constructed to distinguish the metabolic changes between the negative control group and the PTL-treated group in TFK1 cells. Next, enzyme-linked immunosorbent assay (ELISA) was applied to investigate the changes of metabolic enzymes associated with significantly alerted metabolites. Finally, the metabolic network related to key metabolic enzymes, metabolites, and metabolic pathways was established using MetaboAnalyst 5.0 and Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway Database.

RESULTS

PTL treatment could induce the proliferation inhibition and apoptosis of TFK1 in a concentration-dependent manner. Forty-three potential biomarkers associated with the antitumor effect of PTL were identified, which primarily related to glutamine and glutamate metabolism, alanine, aspartate and glutamate metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, arginine biosynthesis, arginine and proline metabolism, glutathione metabolism, nicotinate and nicotinamide metabolism, pyrimidine metabolism, fatty acid metabolism, phospholipid catabolism, and sphingolipid metabolism. Pathway analysis of upstream and downstream metabolites, we found three key metabolic enzymes, including glutaminase (GLS), γ-glutamyl transpeptidase (GGT), and carnitine palmitoyltransferase 1 (CPT1), which mainly involved in glutamine and glutamate metabolism, glutathione metabolism, and fatty acid metabolism. The changes of metabolic enzymes associated with significantly alerted metabolites were consistent with the levels of metabolites, and the metabolic network related to key metabolic enzymes, metabolites, and metabolic pathways was established. PTL may exert its antitumor effect against cholangiocarcinoma by disturbing metabolic pathways. Furthermore, we selected two positive control agents that are considered as first-line chemotherapy standards in cholangiocarcinoma therapy to verify the reliability and accuracy of our metabolomic study on PTL.

CONCLUSION

This research enhanced our comprehension of the metabolic profiling and mechanism of PTL treatment on cholangiocarcinoma cells, which provided some references for further research into the anti-cancer mechanisms of other drugs.

UHPLC-QTOF-MS-based untargeted metabolomic authentication of Chinese red wines according to their grape varieties

Wine is a very popular alcoholic drink owing to its health benefits of antioxidant effects. However, profits-driven frauds of wine especially false declarations of variety frequently occurred in markets. In this work, an UHPLC-QTOF-MS-based untargeted metabolomics method was developed for metabolite profiling of 119 bottles of Chinese red wines from four varieties (Cabernet Sauvignon, Merlot, Cabernet Gernischt, and Pinot Noir). The metabolites of red wines from different varieties were assessed using orthogonal partial least-squares discriminant analysis (OPLS-DA) and analyzed using KEGG metabolic pathway analysis. Results showed that the differential compounds among different varieties of red wines are mainly flavonoids, phenols, indoles and amino acids. The KEGG metabolic pathway analysis showed that indoles metabolism and flavonoids metabolism are closely related to wine varieties. Based on the differential compounds, OPLS-DA models could identify external validation wine samples with a total correct rate of 90.9 % in positive ionization mode and 100 % in negative ionization mode. This study indicated that the developed untargeted metabolomics method based on UHPLC-QTOF-MS is a potential tool to identify the varieties of Chinese red wines.

A comparison of hydrophilic interaction liquid chromatography and capillary electrophoresis for the metabolomics analysis of human serum

Cationic, anionic, zwitterionic and, partially polar metabolites are very important constituents of blood serum. Several of these metabolites underpin the core metabolism of cells (e.g., Krebs cycle, urea cycle, proteins synthesis, etc.), while others might be considered ancillary but still important to grasp the status of any organism through blood serum analysis. Due to its wide chemical diversity, modern metabolomics analysis of serum is still struggling to provide a complete and comprehensive picture of the polar metabolome, due to the limitations of each specific analytical method. In this study, two metabolomics-based analytical methods using the most successful techniques for polar compounds separation in human serum samples, namely hydrophilic interaction liquid chromatography (HILIC) and capillary electrophoresis (CE), are evaluated, both coupled to a high-resolution time-of-flight mass spectrometer via electrospray ionization (ESI-Q-TOF-MS). The performance of the two methods have been compared using five terms of comparison, three of which are specific to metabolomics, such as (1) compounds' detectability (2) Pezzatti score (Pezzatti et al. 2018), (3) intra-day precision (repeatability), (4) ease of automatic analysis of the data (through a common deconvolution alignment and extrapolation software, MS-DIAL, and (5) time & cost analysis. From this study, HILIC-MS proved to be a better tool for polar metabolome analysis, while CE-MS helped identify some interesting variables that gave it interest in completing metabolome coverage in metabolomics studies. Finally, in this framework, MS-DIAL demonstrates for the first time its ability to process CE data for metabolomics, although it is not designed for it.

[Analysis of metabolite differences in skin between Clapp's Favorite and its mutant Red Clapp's Favorite through non-targeted metabolomics]

Red Clapp's Favorite is the red mutation cultivar of the pear cultivar Clapp's Favorite. Fruit color is an important feature of pear fruits, with red skin generally attracting consumers. Anthocyanin, chlorophyll, and carotenoids are the most important pigments in the color formation of fruits. The red color of pear skin is mainly due to the concentration and composition of anthocyanin. Metabolomics is an emerging discipline that focuses on the qualitative and quantitative analysis of small metabolites with low molecular weight in biological cells and tissues. As an important part of systems biology, it is an effective means to solve many complex biological problems. Studies have analyzed pigment content, composition, and differentially expressed genes in the skin of green and red pears from various aspects. Anthocyanins are responsible for physiological activity on regulating pathways. The aim of this study was to discover differential metabolites in the skin of Clapp's Favorite and its red mutation cultivar Red Clapp's Favorite. The metabolic components were detected using high-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). Chromatographic experiments were performed on an HSS T3 column (100 mm×2.1 mm, 1.8 μm) by using a mobile phase consisting of 0.1% (v/v) formic acid in acetonitrile and water, and mass spectrometry was conducted in the positive and negative modes by electrospray ionization (ESI). Red Clapp's Favorite and Clapp's Favorite were collected from the pear germplasm resource nursery of Yantai Institute of Agricultural Sciences in Shandong. The data were analyzed by principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) as well as cluster analysis and heat map. The first two principal components exhibited 62.3% and 8% of the total variance in the positive and negative ion modes, respectively. PCA can generally reflect metabolite differences between the two groups of samples, and there are significant differences in metabolites between the two cultivars. The results showed that PLS-DA clearly distinguishes the two groups of samples, which can be used to analyze the subsequent difference in components. The compounds were identified based on data retrieved from the PMDB databases according to the accurate mass number, secondary fragment, and isotope distribution. The results showed that the metabolite content in the skin of Red Clapp's Favorite and Clapp's Favorite were significant. There were 83 different metabolites (P<0.05, variable importance in project (VIP)≥1), including phenols and amino acids, which are involved in flavonoid metabolism, amino acid metabolism, phenyl propanoid biosynthesis, and other metabolic pathways, including 5 polyphenols, 3 flavonoids, 1 amino acid and derivatives, 8 phenylpropanes, 2 anthocyanins, 5 proanthocyanidins, 6 flavanols, 14 flavonols, 2 isoflavones, 13 triterpenoids, 3 organic acids and derivatives, 1 vitamin, 3 organic acids and derivatives, 15 lipids, and 2 other compounds. The chlorogenic acid and crypto-chlorogenic acid in Red Clapp's Favorite are 2.40 and 3.46 times as much as those in Clapp's Favorite. The anthocyanins of cornulin 3-glucoside and cornulin 3-galactoside were 10.235 and 9.394 times, respectively. Phenolic epicatechin and catechin increased by 4.689 and 4.635, respectively. The content of phenylpropane 3, 4-dihydroxycinnamic acid in Red Clapp's Favorite increased by 3.13 times. Among the 83 differential metabolites, 23 metabolites were enriched in the pathway. To display the relationship between the samples and the differences in metabolites among the different samples intuitively, hierarchical clustering and heat map analysis were performed on the metabolite expression levels with significant differences in the enrichment pathways. The Kyoto Encyclopedia of Genes and Genomes database was used to further analyze the pathway enrichment of different metabolites. According to the results, there were 6 metabolic pathways (P<0.05): flavonoid biosynthesis, flavone and flavonol biosynthesis, phenylpropanoid biosynthesis, butanoate metabolism, phenylalanine metabolism, and tyrosine metabolism. Plant secondary metabolism shows a complex diversity. This study would screen out other pathways affecting the biosynthesis of flavonoids, which could provide reference for the further study of biosynthesis and biological function of flavonoids in red fruits. This study provides a useful reference for metabolomics of red pears, which could provide a theoretical reference for the quality analysis and biological function research of pears.

Food Metabolites as Tools for Authentication, Processing, and Nutritive Value Assessment

Secondary metabolites are molecules with unlimited applications that have been gaining importance in various industries and studied from many angles. They are mainly used for their bioactive capabilities, but due to the improvement of sensibility in analytical chemistry, they are also used for authentication and as a quality control parameter for foods, further allowing to help avoid food adulteration and food fraud, as well as helping understand the nutritional value of foods. This manuscript covers the examples of secondary metabolites that have been used as qualitative and authentication molecules in foods, from production, through processing and along their shelf-life. Furthermore, perspectives of analytical chemistry and their contribution to metabolite detection and general perspectives of metabolomics are also discussed.

Metabolomics analysis of the soapberry (Sapindus mukorossi Gaertn.) pericarp during fruit development and ripening based on UHPLC-HRMS

Soapberry (Sapindus mukorossi Gaertn.) is a multi-functional tree with widespread application in toiletries, biomedicine, biomass energy, and landscaping. The pericarp of soapberry can be used as a medicine or detergent. However, there is currently no systematic study on the chemical constituents of soapberry pericarp during fruit development and ripening, and the dynamic changes in these constituents still unclear. In this study, a non-targeted metabolomics approach using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) was used to comprehensively profile the variations in metabolites in the soapberry pericarp at eight fruit growth stages. The metabolome coverage of UHPLC-HRMS on a HILIC column was higher than that of a C18 column. A total of 111 metabolites were putatively annotated. Principal component analysis and hierarchical clustering analysis of pericarp metabolic composition revealed clear metabolic shifts from early (S1–S2) to late (S3–S5) development stages to fruit ripening stages (S6–S8). Furthermore, pairwise comparison identified 57 differential metabolites that were involved in 18 KEGG pathways. Early fruit development stages (S1–S2) were characterized by high levels of key fatty acids, nucleotides, organic acids, and phosphorylated intermediates, whereas fruit ripening stages (S6–S8) were characterized by high contents of bioactive and valuable metabolites, such as troxipide, vorinostat, furamizole, alpha-tocopherol quinone, luteolin, and sucrose. S8 (fully developed and mature stage) was the most suitable stage for fruit harvesting to utilize the pericarp. To the best of our knowledge, this was the first metabolomics study of the soapberry pericarp during whole fruit growth. The results could offer valuable information for harvesting, processing, and application of soapberry pericarp, as well as highlight the metabolites that could mediate the biological activity or properties of this medicinal plant.

A Statistical Workflow to Evaluate the Modulation of Wine Metabolome and Its Contribution to the Sensory Attributes

A data-processing and statistical analysis workflow was proposed to evaluate the metabolic changes and its contribution to the sensory characteristics of different wines. This workflow was applied to rosé wines from different fermentation strategies. The metabolome was acquired by means of two high-throughput techniques: gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS) for volatile and non-volatile metabolites, respectively, in an untargeted approach, while the sensory evaluation of the wines was performed by a trained panel. Wine volatile and non-volatile metabolites modulation was independently evaluated by means of partial least squares discriminant analysis (PLS-DA), obtaining potential markers of the fermentation strategies. Then, the complete metabolome was integrated by means of sparse generalised canonical correlation analysis discriminant analysis (sGCC-DA). This integrative approach revealed a high link between the volatile and non-volatile data, and additional potential metabolite markers of the fermentation strategies were found. Subsequently, the evaluation of the contribution of metabolome to the sensory characteristics of wines was carried out. First, the all-relevant metabolites affected by the different fermentation processes were selected using PLS-DA and random forest (RF). Each set of volatile and non-volatile metabolites selected was then related to the sensory attributes of the wines by means of partial least squares regression (PLSR). Finally, the relationships among the three datasets were complementary evaluated using regularised generalised canonical correlation analysis (RGCCA), revealing new correlations among metabolites and sensory data.

FoodOmicsGR_RI. A Consortium for Comprehensive Molecular Characterisation of Food Products

The national infrastructure FoodOmicsGR_RI coordinates research efforts from eight Greek Universities and Research Centers in a network aiming to support research and development (R&D) in the agri-food sector. The goals of FoodOmicsGR_RI are the comprehensive in-depth characterization of foods using cutting-edge omics technologies and the support of dietary/nutrition studies. The network combines strong omics expertise with expert field/application scientists (food/nutrition sciences, plant protection/plant growth, animal husbandry, apiculture and 10 other fields). Human resources involve more than 60 staff scientists and more than 30 recruits. State-of-the-art technologies and instrumentation is available for the comprehensive mapping of the food composition and available genetic resources, the assessment of the distinct value of foods, and the effect of nutritional intervention on the metabolic profile of biological samples of consumers and animal models. The consortium has the know-how and expertise that covers the breadth of the Greek agri-food sector. Metabolomics teams have developed and implemented a variety of methods for profiling and quantitative analysis. The implementation plan includes the following research axes: development of a detailed database of Greek food constituents; exploitation of "omics" technologies to assess domestic agricultural biodiversity aiding authenticity-traceability control/certification of geographical/genetic origin; highlighting unique characteristics of Greek products with an emphasis on quality, sustainability and food safety; assessment of diet's effect on health and well-being; creating added value from agri-food waste. FoodOmicsGR_RI develops new tools to evaluate the nutritional value of Greek foods, study the role of traditional foods and Greek functional foods in the prevention of chronic diseases and support health claims of Greek traditional products. FoodOmicsGR_RI provides access to state-of-the-art facilities, unique, well-characterised sample sets, obtained from precision/experimental farming/breeding (milk, honey, meat, olive oil and so forth) along with more than 20 complementary scientific disciplines. FoodOmicsGR_RI is open for collaboration with national and international stakeholders.

Use of Untargeted Liquid Chromatography-Mass Spectrometry Metabolome To Discriminate Italian Monovarietal Red Wines, Produced in Their Different Terroirs

The aim of this project was to register, in a liquid chromatography-mass spectrometry-based untargeted single-batch analysis, the metabolome of 11 single-cultivar, single-vintage Italian red wines (Aglianico, Cannonau, Corvina, Montepulciano, Nebbiolo, Nerello, Primitivo, Raboso, Sagrantino, Sangiovese, and Teroldego) from 12 regions across Italy, each one produced in their terroirs under ad hoc legal frameworks to guarantee their quality and origin. The data provided indications regarding the similarity between the cultivars and highlighted a rich list of putative biomarkers of origin wines (pBOWs) characterizing each individual cultivar-terroir combination, where Primitivo, Teroldego, and Nebbiolo had the maximum number of unique pBOWs. The pBOWs included anthocyanins (Teroldego), flavanols (Aglianico, Sangiovese, Nerello, and Nebbiolo), amino acids and N-containing metabolites (Primitivo), hydroxycinnamates (Cannonau), and flavonols (Sangiovese). The raw data generated in this study are publicly available and, therefore, accessible and reusable as a baseline data set for future investigations.

Liquid Chromatography-Mass Spectrometry-Based Metabolomics for Understanding the Compositional Changes Induced by Oxidative or Anoxic Storage of Red Wines

The aim of this work was to study the physicochemical changes of eight red wines stored under conditions differing in O₂ exposure and temperature and time under anoxia. The methods used to analyze the wines included the measurement of volatile sulfur compounds, color, tannin (T) polymerization, and liquid chromatography-mass spectrometry untargeted metabolomic fingerprint. After 3 months, the color of the oxidized samples evolved 4-5 times more intensively than in wines stored under anoxia. The major metabolomic differences between oxidative and anoxic conditions were linked to reactions of acetaldehyde (favored in oxidative) and SO₂ (favored in anoxia). In the presence of oxygen, the C-4 carbocation of flavanols delivered ethyl-linked tannin-anthocyanin (T-A) and tannin-tannin (T-T) adducts, pyranoanthocyanins, and sulfonated indoles, while under reduction, the C-4 carbocation delivered direct linked T-A adducts, rearranged T-T adducts, and sulfonated tannins. Some of these last reactions could be related to the accumulation of reduced species, eventually ending with reductive off-odors.

Polyphenols: Natural Antioxidants to Be Used as a Quality Tool in Wine Authenticity

Polyphenols are a diverse group of compounds possessing various health-promoting properties that are of utmost importance for many wine sensory attributes. Apart from genetic and environmental parameters, the implementation of specific oenological practices as well as the subsequent storage conditions deeply affect the content and nature of the polyphenols present in wine. However, polyphenols are effectively employed in authenticity studies. Provision of authentic wines to the market has always been a prerequisite meaning that the declarations on the wine label should mirror the composition and provenance of this intriguing product. Nonetheless, multiple cases of intentional or unintentional wine mislabeling have been recorded alarming wine consumers who demand for strict controls safeguarding wine authenticity. The emergence of novel platforms employing instrumentation of exceptional selectivity and sensitivity along with the use of advanced chemometrics such as NMR (nuclear magnetic resonance)- and MS (mass spectrometry)-based metabolomics is considered as a powerful asset towards wine authentication.

Recent advances in the application of metabolomics for food safety control and food quality analyses

As one of the omics fields, metabolomics has unique advantages in facilitating the understanding of physiological and pathological activities in biology, physiology, pathology, and food science. In this review, based on developments in analytical chemistry tools, cheminformatics, and bioinformatics methods, we highlight the current applications of metabolomics in food safety, food authenticity and quality, and food traceability. Additionally, the combined use of metabolomics with other omics techniques for "foodomics" is comprehensively described. Finally, the latest developments and advances, practical challenges and limitations, and requirements related to the application of metabolomics are critically discussed, providing new insight into the application of metabolomics in food analysis.

Discrimination of rosé wines using shotgun metabolomics with a genetic algorithm and MS ion intensity ratios

A rapid Ultra Performance Liquid Chromatography coupled with Quadrupole/Time Of Flight Mass Spectrometry (UPLC-QTOF-MS) method was designed to quickly acquire high-resolution mass spectra metabolomics fingerprints for rosé wines. An original statistical analysis involving ion ratios, discriminant analysis, and genetic algorithm (GA) was then applied to study the discrimination of rosé wines according to their origins. After noise reduction and ion peak alignments on the mass spectra, about 14 000 different signals were detected. The use of an in-house mass spectrometry database allowed us to assign 72 molecules. Then, a genetic algorithm was applied on two series of samples (learning and validation sets), each composed of 30 commercial wines from three different wine producing regions of France. Excellent results were obtained with only four diagnostic peaks and two ion ratios. This new approach could be applied to other aspects of wine production but also to other metabolomics studies.

LC-MS untargeted approach showed that methyl jasmonate application on Vitis labrusca L. grapes increases phenolics at subtropical Brazilian regions

INTRODUCTION

Vitis labrusca L. grapes are largely cultivated in Brazil, but the tropical climate negatively affects the phenols content, especially anthocyanin. According to the projections of the incoming climatic changes, the climate of several viticulture zone might change to tropical. Therefore, researches are focusing on increasing grape phenols content; with methyl jasmonate application (MeJa) is considered a good alternative.

OBJECTIVES

The aim was to investigate with an untargeted approach the metabolic changes caused by the MeJa pre-harvest application on two Vitis labrusca L. cultivars grapes, both of them grown in two Brazilian regions.

METHODS

Isabel Precoce and Concord grapes cultivated under subtropical climate, in the south and southeast of Brazil, received MeJa pre-harvest treatment. Grape metabolome was extracted and analyzed with a MS based metabolomics protocol by UPLC-HRMS-QTOF.

RESULTS

Unsupervised data analysis revealed a clear separation between the two regions and the two cultivars, while supervised data analysis revealed biomarkers between the MeJa treatment group and the control group. Among the metabolites positively affected by MeJa were (a) flavonoids with a high degree of methylation at the B-ring (malvidin and peonidin derivatives and isorhamentin) for Isabel Precoce grapes; (b) glucosides of hydroxycinnamates, gallocatechin, epigallocatechin and cis-piceid for Concord grapes; and (c) hydroxycinnamates esters with tartaric acid, and procyanidins for the Southeast region grapes.

CONCLUSION

These results suggest that MeJa can be used as elicitor to secondary metabolism in grapes grown even under subtropical climate, affecting phenolic biosynthesis.

Quality changes in perilla seed powder related to storage duration and temperature

Perilla seed powder (PSP) was stored at 25 °C, 35 °C, and 45 °C for 8 weeks. Changes in the metabolite profiles of the powders, including fatty acids, were monitored. Correlations between these changes and quality parameters, including lipid oxidation, color, and antioxidant activity, were analyzed to evaluate the effects of storage duration and temperature on PSP quality. Acid values increased significantly with the duration of storage, but not with temperature. Multivariate statistical analysis was performed to identify differences among the metabolite profiles. The PSP sample stored for 1 week at 45 °C and all samples stored at 25 °C and 35 °C were grouped separately from the control and samples stored at 45 °C for more than 4 weeks. Among the many metabolites associated with these differences, lysophosphatidylethanolamines, tocopherol, sitosterol, tryptophan, 12-hydroxyjasmonic acid glucoside, and maltose correlated negatively with quality parameters with the exception of L* and antioxidant activity. Luteolin, apigenin, luteolin 4'-methyl ester, citric acid, isocitric acid, 9(S)-HPODE, and 3,5-octadien-2-one correlated positively with quality. Although the quantities of some antioxidants and lipids decreased during storage, the results suggested that the quality of PSP samples stored at 25 °C, 35 °C, and 45 °C for 8 weeks was acceptable. This was because lipid oxidation promoted by the storage environment was limited by antioxidants in the samples. These metabolites could be useful for monitoring changes in PSP quality.

A targeted approach for studying the effect of sugar bee feeding on the metabolic profile of Royal Jelly

Royal Jelly (RJ) constitutes one of the most popular beehive products and for this reason the use of inexpensive sweeteners during its production remains an important quality issue. In the present study we report results of metabolic profiling of RJ samples obtained after the application of artificial bee-feeding using different feeding protocols. The hydrophilic content of RJ samples was assessed by applying (HILIC)UPLC-MS/MS. In total 96 crude RJ samples were analysed with the developed method. Multivariate statistical analysis revealed clear differentiation between the RJ samples obtained from control (non-fed) bees and samples obtained after feeding. In total 27 out of 57 detected molecules were statistically found to be significantly altered in the different comparisons. Among them some amino acids (e.g. tryptophan, lysine), amino acid derivatives (pyroglutamic acid), amines (cadaverine, TMAO, etc.), carbohydrates and vitamins were found as potential markers. The results of the study could be further used for the development of an LC-MS based analytical tool for RJ quality control assessment.

The Relevance of Mass Spectrometry Analysis for Personalized Medicine through Its Successful Application in Cancer "Omics"

Mass spectrometry (MS) is an essential analytical technology on which the emerging omics domains; such as genomics; transcriptomics; proteomics and metabolomics; are based. This quantifiable technique allows for the identification of thousands of proteins from cell culture; bodily fluids or tissue using either global or targeted strategies; or detection of biologically active metabolites in ultra amounts. The routine performance of MS technology in the oncological field provides a better understanding of human diseases in terms of pathophysiology; prevention; diagnosis and treatment; as well as development of new biomarkers; drugs targets and therapies. In this review; we argue that the recent; successful advances in MS technologies towards cancer omics studies provides a strong rationale for its implementation in biomedicine as a whole.

Metabolomics biotechnology, applications, and future trends: a systematic review

Given the highly increased incidence of human diseases, a better understanding of the related mechanisms regarding endogenous metabolism is urgently needed. Mass spectrometry-based metabolomics has been used in a variety of disease research areas. However, the deep research of metabolites remains a difficult and lengthy process. Fortunately, mass spectrometry is considered to be a universal tool with high specificity and sensitivity and is widely used around the world. Mass spectrometry technology has been applied to various basic disciplines, providing technical support for the discovery and identification of endogenous substances in living organisms. The combination of metabolomics and mass spectrometry is of great significance for the discovery and identification of metabolite biomarkers. The mass spectrometry tool could further improve and develop the exploratory research of the life sciences. This mini review discusses metabolomics biotechnology with a focus on recent applications of metabolomics as a powerful tool to elucidate metabolic disturbances and the related mechanisms of diseases.

Given the highly increased incidence of human diseases, a better understanding of the related mechanisms regarding endogenous metabolism is urgently needed.

Wine and grape marc spirits metabolomics

INTRODUCTION

Mass spectrometry (MS)-based and nuclear magnetic resonance (NMR) spectroscopic analyses play a key role in the field of metabolomics due to their important advantages. The use of metabolomics in wine and grape marc spirits allows a more holistic perspective in monitoring and gaining information on the making processes and thus it can assist on the improvement of their quality.

OBJECTIVES

This review surveys the latest metabolomics approaches for wine and grape marc spirits with a focus on the description of MS-based and NMR spectroscopic analytical techniques.

METHODS

We reviewed the literature to identify metabolomic studies of wine and grape marc spirits that were published until the end of 2017, with the key term combinations of 'metabolomics', 'wine' and 'grape marc spirits'. Through the reference lists from these studies, additional articles were identified.

RESULTS

The results of this review showed that the application of different metabolomics approaches has significantly increased the knowledge of wine metabolome and grape marc spirits; however there is not yet a single analytical platform that can completely separate, detect and identify all metabolites in one analysis.

CONCLUSIONS

The authentication and quality control of wines and grape marc spirits has to be taken with caution, since the product's chemical composition could be affected by many factors. Despite intrinsic limitations, NMR spectroscopy and MS based strategies remain the key analytical methods in metabolomics studies. Authenticity, traceability and health issues related to their consumption are the major research initiatives in wine and grape marc spirits metabolomics analysis.

Grape and Wine Metabolomics to Develop New Insights Using Untargeted and Targeted Approaches

Chemical analysis of grape juice and wine has been performed for over 50 years in a targeted manner to determine a limited number of compounds using Gas Chromatography, Mass-Spectrometry (GC-MS) and High Pressure Liquid Chromatography (HPLC). Therefore, it only allowed the determination of metabolites that are present in high concentration, including major sugars, amino acids and some important carboxylic acids. Thus, the roles of many significant but less concentrated metabolites during wine making process are still not known. This is where metabolomics shows its enormous potential, mainly because of its capability in analyzing over 1000 metabolites in a single run due to the recent advancements of high resolution and sensitive analytical instruments. Metabolomics has predominantly been adopted by many wine scientists as a hypothesis-generating tool in an unbiased and non-targeted way to address various issues, including characterization of geographical origin (terroir) and wine yeast metabolic traits, determination of biomarkers for aroma compounds, and the monitoring of growth developments of grape vines and grapes. The aim of this review is to explore the published literature that made use of both targeted and untargeted metabolomics to study grapes and wines and also the fermentation process. In addition, insights are also provided into many other possible avenues where metabolomics shows tremendous potential as a question-driven approach in grape and wine research.

High-Resolution Mass Spectrometry Identification of Secondary Metabolites in Four Red Grape Varieties Potentially Useful as Traceability Markers of Wines

Liquid chromatography coupled to high-resolution mass spectrometry (LC-Q/TOF) is a powerful tool to perform chemotaxonomic studies through identification of grape secondary metabolites. In the present work, the metabolomes of four autochthonous Italian red grape varieties including the chemical classes of anthocyanins, flavonols/flavanols/flavanones, and terpenol glycosides, were studied. By using this information, the metabolites that can potentially be used as chemical markers for the traceability of the corresponding wines were proposed. In Raboso wines, relatively high abundance of both anthocyanic and non-anthocyanic acyl derivatives, is expected. Potentially, Primitivo wines are characterized by high tri-substituted flavonoids, while Corvina wines are characterized by higher di-substituted compounds and lower acyl derivatives. Negro Amaro wine’s volatile fraction is characterized by free monoterpenes, such as α-terpineol, linalool, geraniol, and Ho-diendiol I. A similar approach can be applied for the traceability of other high-quality wines.

High-resolution mass spectrometry metabolomics of grape chemical markers to reveal use of not-allowed varieties in the production of Amarone and Recioto wines

INTRODUCTION

Grape varieties allowed to produce Amarone della Valpolicella and Recioto DOCG wines are strictly regulated by their disciplinary of production. These are Corvina Veronese and Corvinone grapes, to a lesser extent also Rondinella can be used. The use of other varieties, is not allowed.

OBJECTIVES

To identify chemical markers suitable to reveal addition of two not allowed grape varieties to the Corvina/Corvinone blend, such as Primitivo or Negro Amaro.

METHODS

The identification of the secondary metabolites of the four grape varieties was conducted by high-resolution mass spectrometry (HRMS) metabolomics. By using the signals of these metabolites the indexes able to identify the presence of Primitivo or Negro Amaro grapes in the Corvina/Corvinone 1:1 blend were calculated.

RESULTS

Indexes of laricitrin (Lr), delphinidin (Dp), and petunidin (Pt) signals were effective to identify the use of 10% Primitivo, while α-terpineol pentosyl-hexoside and linalool pentosyl-hexoside reveal the presence of Negro Amaro in the grape blend.

CONCLUSIONS

Varietal markers useful to detect the presence of Primitivo and Negro Amaro in the grape blend were identified by HRMS metabolomics, a method suitable to check the identity of grapes on arrival at the winery, as well as the fermenting musts. The effectiveness of the identified markers in the final wines have to be confirmed. Potentially, a similar approach can be used to reveal analogous frauds performed on other high-quality wines.

Kinetic study of continuous liquid-liquid extraction of wine with real-time detection

Kinetic optimization of continuous liquid-liquid extraction (CLLE) can shorten sample preparation times and reduce losses of labile or volatile analytes. Here, we coupled a downscaled CLLE apparatus with atmospheric pressure chemical ionization interface of triple quadrupole mass spectrometer. Real-time sampling was guided by an Arduino-based programmable logic controller. The recorded datasets were processed to compute the extraction rate constants for the target analytes. The extraction time in subsequent on-line experiments was set to 180 min as a compromise between the reduction of the analysis time and maximizing its yield. Interestingly, off-line analysis of the extract produced different results than on-line analysis pointing to the immanent degradation of the collected extract aliquots. Next, we implemented this hyphenated system in the analysis of red wine samples, which were stored during different periods of time after opening the bottle. The results reveal differences in the depletion of the volatile wine components during storage.

The impact of SO2 on wine flavanols and indoles in relation to wine style and age

Wine has one of the broadest chemical profiles, and the common oenological practice of adding the antioxidant and antimicrobial sulfur dioxide has a major impact on its metabolomic fingerprint. In this study, we investigated novel discovered oenological reactions primarily occurring between wine metabolites and sulfur dioxide. The sulfonated derivatives of epicatechin, procyanidin B2, indole acetic acid, indole lactic acid and tryptophol were synthesized and for the first time quantified in wine. Analysis of 32 metabolites in 195 commercial wines (1986-2016 vintages) suggested that sulfonation of tryptophan metabolites characterised white wines, in contrast to red wines, where sulfonation of flavanols was preferred. The chemical profile of the oldest wines was strongly characterised by sulfonated flavanols and indoles, indicating that could be fundamental metabolites in explaining quality in both red and white aged wines. These findings offer new prospects for more precise use of sulfur dioxide in winemaking.

Targeted profiling of hydrophilic constituents of royal jelly by hydrophilic interaction liquid chromatography-tandem mass spectrometry

In the present work a Hydrophilic Interaction Liquid Chromatography-tandem Mass Spectrometry (HILIC-MS/MS) method was developed for the efficient separation and quantification of a large number of small polar bioactive molecules in Royal Jelly. The method was validated and provided satisfactory detection sensitivity for 88 components. Quantification was proven to be precise for 64 components exhibiting good linearity, recoveries R% >90% for the majority of analytes and intra- and inter-day precision from 0.14 to 20% RSD. Analysis of 125 fresh royal jelly samples of Greek origin provided useful information on royal jelly's hydrophilic bioactive components revealing lysine, ribose, proline, melezitose and glutamic acid to be in high abundance. In addition the occurrence of 18 hydrophilic nutrients which have not been reported previously as royal jelly constituents is shown.

Hyphenated MS-based targeted approaches in metabolomics

Review of targeted metabolomics, with a focus on the description of analytical methods.

Effects of in vitro digestion and storage on the phenolic content and antioxidant capacity of a red grape pomace

Red grape pomace (RGP) is a major winery by-product with interesting applications due to its high phenolic content and antioxidant capacity. Effects of in vitro gastrointestinal digestion and storage on the phenolic content and antioxidant capacity of RGP were studied. RGP polyphenols were stable under stomach-mimicking conditions and more sensitive to small intestine conditions, reducing anthocyanins and flavonols. After 3- and 6-month storage, at either 4 or 25 °C, there were no changes in the total phenolic and condensed tannin content, or antioxidant capacity (evaluated by ABTS, FRAP, ORAC assays); however, after 9 months these parameters decreased. Contrarily, chromatic b* values were higher, thus the samples had more intense red color, which may be related to the increased condensed tannin content. Storage time or temperature induced no changes in microbiological load. RGP preserves high antioxidant capacity after storage and in vitro digestion and thus presents potential as a functional ingredient or nutraceutical.

Metabolic Effects of the pksCT Gene on Monascus aurantiacus Li As3.4384 Using Gas Chromatography--Time-of-Flight Mass Spectrometry-Based Metabolomics

Monascus spp. have been used for the production of natural pigments and bioactive compounds in China for several centuries. Monascus can also produce the mycotoxin citrinin, restricting its use. Disruption of the pksCT gene in Monascus aurantiacus Li AS3.4384 reduces citrinin production capacity of this strain (Monascus PHDS26) by over 98%. However, it is unclear how other metabolites of M. aurantiacus Li AS3.4384 (the wild-type strain) are affected by the pksCT gene. Here, we used metabolomic analyses to compare red yeast rice (RYR) metabolite profiles of the wild-type strain and Monascus PHDS26 at different stages of solid-state fermentation. A total of 18 metabolites forming components within the glycolysis, acetyl-CoA, amino acid, and tricarboxylic acid (TCA) cycle metabolic processes were found to be altered between the wild-type strain and Monascus PHDS26 at different stages of solid-state fermentation. Thus, these findings provide important insights into the metabolic pathways affected by the pksCT gene in M. aurantiacus.

Wine metabolomics reveals new sulfonated products in bottled white wines, promoted by small amounts of oxygen

The impact of minute amounts of oxygen in the headspace on the post-bottling development of wine is generally considered to be very important, since oxygen can either damage or improve the quality of wine. This project aimed to gain new experimental evidence about the chemistry of the interaction between wine and oxygen. The experimental design included 216 bottles of 12 different white wines produced from 6 different cultivars (Inzolia, Muller Thurgau, Chardonnay, Grillo, Traminer and Pinot gris). Half of them were bottled using the standard industrial process with inert headspace and the other half without inert gas and with extra headspace. After 60 days of storage at room temperature, the wines were analysed using an untargeted LC-MS method. The use of a detailed holistic analysis workflow, with several levels of quality control and marker selection, gave 35 metabolites putatively induced by the different amounts of oxygen. These metabolite markers included ascorbic acid, tartaric acid and various sulfonated compounds observed in wine for the first time (e.g. S-sulfonated cysteine, glutathione and pantetheine; and sulfonated indole-3-lactic acid hexoside and tryptophol). The consumption of SO2 mediated by these sulfonation reactions was promoted by the presence of higher levels of oxygen on bottling.