A grape and wine chemodiversity comparison of different appellations in Burgundy: vintage vs terroir effects

Continuum of non-targeted data for long term study of complex samples generated by direct infusion ultra-high resolution mass spectrometry

Non-targeted chemical analysis is a powerful tool for exploration of the unknown chemistry of complex matrices such as food, biological, geochemical, environmental and even extra-terrestrial samples. It allows researchers to ask open, unbiased questions about their system chemistry. Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS) offers these options and has been widely used to study complex mixtures, with its unmatched mass resolution enabling direct infusion methods and eliminating the challenges of chromatographic alignment in large-scale longitudinal projects. In this article, we demonstrate the use of FT-ICR-MS for generating a dataset for hundreds of complex samples with diverse chemistries over a period of 6 years and 32 batches, allowing confident comparison of data between samples from different batches. The resulting chemical database will be continuously expanded in future and retrospectively interrogated to test new hypotheses utilizing data of past projects and new knowledge of coming projects. We discuss the experimental setup and how other researchers could apply the same approaches, which is relevant for wide ranging applications and research fields.

Vineyard Location Impact on the Composition and Quality of Wines from International and Native Varieties Grown in Drama, Greece

The objective of this work was to investigate the effect of location on the composition and quality of wines from the viticultural zone PGI Drama. Grapes from two white (Sauvignon blanc, Assyrtiko) and three red varieties (Merlot, Cabernet Sauvignon, Agiorgitiko) were collected from nine locations within the zone during 2022. The vineyards span distances ranging from several hundred meters to 100 km, and their altitudes vary from 90 to nearly 820 m. Vinification was performed following the same protocol according to the type of wine. Wines were analyzed for quality parameters such as pH, total acidity, alcohol, and residual sugar content. In addition, elemental composition, phenolic content, antioxidant capacity, and sensory attributes of the wines were assessed. The obtained results suggested that besides the type of wine and variety, the location significantly affects the quality parameters of the wine. PCA analysis revealed that location is an important factor affecting the wine quality. The areas north and northwest proved more suitable for specific varieties, as they produce wines with more distinct organoleptic characteristics. The results provide insights into the behavior of international and native varieties in the face of global warming and assist in decisions concerning the most suitable plant material.

Identifying the vintage of French wine using stable isotopes, elemental fingerprints, and a data-driven but explainable approach

Stable isotopes and elemental fingerprints were employed as indicators to evaluate the vintage of French wine using climate factors and data-driven models. δ13C of wine ethanol and glycine, and δ18O of wine water and 16 elements were determined in wine from Bordeaux, Burgundy, and Languedoc-Roussillon. Results revealed that isotopic and elemental signatures from various vintages were influenced by precipitation and temperature. If there was less precipitation and higher temperatures during the grape ripening phase, isotopic and elemental signatures had a positive impact on the grapes, resulting in superior quality French wine. Data-driven models achieved excellent accuracy to identify vintages with the identification accuracy up to 72.0 %, and even higher accuracy (up to 95.0 %) from the Bordeaux region. Explainable methods were employed to select the top-5 and top-10 variables for each region under different data-driven models, yielding results comparable to those from a full set of variables.

The high-resolution molecular portrait of coffee: A gateway to insights into its roasting chemistry and comprehensive authenticity profiles

The direct-infusion of 130 coffee samples into a Fourier-transform ion cyclotron mass spectrometer (FT-ICR-MS) provided an ultra-high resolution perspective on the molecular complexity of coffee: The exceptional resolving power and mass accuracy (± 0.2 ppm) facilitated the annotation of unambiguous molecular formulas to 11,500 mass signals. Utilizing this molecular diversity, we extracted hundreds of compound signals linked to the roasting process through guided Orthogonal Partial Least Squares (OPLS) analysis. Visualizations such as van Krevelen diagrams and Kendrick mass defect analysis provided deeper insights into the intrinsic compositional nature of these compounds and the complex chemistry underlying coffee roasting. Predictive OPLS-DA models established universal molecular profiles for rapid authentication of Coffea arabica versus Coffea canephora (Robusta) coffees. Compositional analysis revealed Robusta specific signals, indicative of tryptophan-conjugates of hydroxycinnamic acids. Complementary LC-ToF-MS2 confirmed their compound class, building blocks and structures. Their water-soluble nature allows for application across raw and roasted beans, as well as in ready-made coffee products.

Untargeted metabolomics analyses to identify a new sweet compound released during post-fermentation maceration of wine

The sensory quality of a wine is mainly based on its aroma and flavor. Sweetness contributes in the gustatory balance of red wines. The investigation of compounds involved in this flavor was based on empirical observations, such as the increase in wine sweetness during yeast autolysis, concomitant to post-fermentation maceration in red winemaking. An untargeted metabolomics approach using UHPLC-HRMS has been developed to discover a new sweet molecule released during this stage. Among several markers highlighted, one compound was selected to be isolated by various separative techniques. It was unambiguously identified by NMR as N6-succinyladenosine and is reported for the first time in wine at an average concentration of 3.16 mg/L in 85 red wines. Furthermore, sensory analysis has highlighted its sweetness. In addition to discovering a new sweet compound in wine, this study proposes new tools for studying taste-active compounds in natural matrices.

Sensory differentiation of Old World wines from New World wines: Has this become more challenging?

The present study aimed to investigate whether, over two recent decades (1997-2018), Old World Wines (OW) and New World Wines (NW) have become more similar or less similar from a sensory perspective. Two 5-year periods were selected within the two-decade period: 1997-2001 (p1) and 2014-2018 (p2). Data comprised descriptors from reviews by seven expert wine critics with descriptors for 31 wines extracted from each review for every year selected. The frequency of citation of descriptors for each of the four wine categories: OW-p1; OW-p2; NW-p1 and NW-p2 was counted. Differences in the citation of descriptors amongst the four categories were calculated by chi-square test. Correspondence analysis (CA) was calculated with the frequency table of descriptors and wine category. In parallel, the level of alcohol was recorded working under the assumption that changing ethanol values might also contribute towards changes in sensory profiles. Significant differences in ethanol content amongst the four categories of wines were calculated with a two-way ANOVA with region (OW or NW) and period (1997-2001; 2014-2018) as fixed factors. The CA demonstrated that time period was a secondary factor after wine region in differentiation of the selected wines by critics. The wines from the latter period showed higher alcohol levels than the wines from the earlier one. The fact that this alcohol increase with time did not result in a convergence in sensory properties amongst wines from the two regions conceivably is due to critics' perception and judgment of wines being affected by historical notions of OW and NW wine differences. Results are discussed in terms of top-down cognitive mechanisms.

Positive Impact of Late Harvest Date on Polyphenolic Composition of Plavac Mali (Vitis vinifera L.) Wine Depends on Location

Asynchronous ripening is a significant challenge in winemaking. Green berries reduce alcohol and pH while increasing acidity. Green berries are rich in bitter and astringent compounds, with an unknown impact on wine quality. The aim of this study was to evaluate the impact of harvest date and vineyard location on the polyphenolic composition of Plavac Mali wines in Dalmatia, Croatia. Experiments were conducted in two locations, Split and Zadar, producing fifteen wines per location from four harvest dates (H1-H4), including green berry wines from H1. The first harvest date occurred 27 days after véraison (DAV) and the last at 69 DAV, corresponding to overripeness. Green berry wines of H1 had low alcohol content up to 4.4% (v/v) in Split. Epigallocatechin was the main flavonoid in those wines, followed by dimer B1 in Split and catechin in Zadar. Green wines from Split had a higher concentration of phenolic acids, flavan-3-ol monomers and dimers. Wines of H3 had the highest concentration of malvidin-3-O-glucoside. With a later harvest date, a dramatic decrease in catechin and dimers was observed in wines from Split, and a decrease in epicatechin, epigallocatechin and dimer B1 in those from Zadar. The final expression of the physiochemical and polyphenolic composition of Plavac Mali wine is determined by the dynamics of harvest date, location and their interactions.

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.

High-Resolution Mass Spectrometry-Based Metabolomics for Increased Grape Juice Metabolite Coverage

The composition of the juice from grape berries is at the basis of the definition of technological ripeness before harvest, historically evaluated from global sugar and acid contents. If many studies have contributed to the identification of other primary and secondary metabolites in whole berries, deepening knowledge about the chemical composition of the sole flesh of grape berries (i.e., without considering skins and seeds) at harvest is of primary interest when studying the enological potential of widespread grape varieties producing high-added-value wines. Here, we used non-targeted DI-FT-ICR-MS and RP-UHPLC-Q-ToF-MS analyses to explore the extent of metabolite coverage of up to 290 grape juices from four Vitis vinifera grape varieties, namely Chardonnay, Pinot noir, Meunier, and Aligoté, sampled at harvest from 91 vineyards in Europe and Argentina, over three successive vintages. SPE pretreatment of samples led to the identification of more than 4500 detected C,H,O,N,S-containing elemental compositions, likely associated with tens of thousands of distinct metabolites. We further revealed that a major part of this chemical diversity appears to be common to the different juices, as exemplified by Pinot noir and Chardonnay samples. However, it was possible to build significant models for the discrimination of Chardonnay from Pinot noir grape juices, and of Chardonnay from Aligoté grape juices, regardless of the geographical origin or the vintage. Therefore, this metabolomic approach opens access to a remarkable holistic molecular description of the instantaneous composition of such a biological matrix, which is the result of complex interplays among environmental, biochemical, and vine growing practices.

The key role of vineyard parcel in shaping flavonoid profiles and color characteristics of Cabernet Sauvignon wines combined with the influence of harvest ripeness, vintage and bottle aging

Recently, revealing the terroir influence on wine chemical features has drawn increasing interest. This study aimed to explain how wine flavonoid signatures were altered by vineyard parcel, harvest ripeness, vintage and bottle aging. Six commercial Cabernet Sauvignon vineyards were selected in the Manas region to produce wines at three harvest ripeness in three seasons (2019-2021) and aged for three years. The six vineyards had little difference in mesoclimate conditions while varying greatly in soil composition. Results showed high vineyard pH (> 8.5) could accelerate grape ripening rate and increase wine flavonol concentration. Vineyards with moderate nutrition produced wines with abundant anthocyanin derivatives and maintained color characteristics during aging. The role of detailed anthocyanin derivatives in regulating wine color was clarified. As the harvest ripeness elevated, wine's flavonoid profiles were altered and gained a higher red color intensity. This work provides chemical mechanisms underlying single-vineyard wines and a theoretical basis for targeted wine production.

Terroir Influence on Polyphenol Metabolism from Grape Canes: A Spatial Metabolomic Study at Parcel Scale

The composition of bioactive polyphenols from grape canes, an important viticultural byproduct, was shown to be varietal-dependent; however, the influence of soil-related terroir factors remains unexplored. Using spatial metabolomics and correlation-based networks, we investigated how continuous changes in soil features and topography may impact the polyphenol composition in grape canes. Soil properties, topography, and grape cane extracts were analyzed at georeferenced points over 3 consecutive years, followed by UPLC-DAD-MS-based metabolomic analysis targeting 42 metabolites. Principal component analyses on intra-vintage metabolomic data presented a good reproducibility in relation to geographic coordinates. A correlation-driven approach was used to explore the combined influence of soil and topographic variables on metabolomic responses. As a result, a metabolic cluster including flavonoids was correlated with elevation and curvature. Spatial metabolomics driven by correlation-based networks represents a powerful approach to spatialize field-omics data and may serve as new field-phenotyping tool in precision agriculture.

Identification of Oak-Barrel and Stainless Steel Tanks with Oak Chips Aged Wines in Ningxia Based on Three-Dimensional Fluorescence Spectroscopy Combined with Chemometrics

With the increased incidence of wine fraud, a fast and reliable method for wine certification has become a necessary prerequisite for the vigorous development of the global wine industry. In this study, a classification strategy based on three-dimensional fluorescence spectroscopy combined with chemometrics was proposed for oak-barrel and stainless steel tanks with oak chips aged wines. Principal component analysis (PCA), partial least squares analysis (PLS-DA), and Fisher discriminant analysis (FDA) were used to distinguish and evaluate the data matrix of the three-dimensional fluorescence spectra of wines. The results showed that FDA was superior to PCA and PLS-DA in classifying oak-barrel and stainless steel tanks with oak chips aged wines. As a general conclusion, three-dimensional fluorescence spectroscopy can provide valuable fingerprint information for the identification of oak-barrel and stainless steel tanks with oak chips aged wines, while the study will provide some theoretical references and standards for the quality control and quality assessment of oak-barrel aged wines.

Untargeted Metabolomics Discriminates Grapes and Wines from Two Syrah Vineyards Located in the Same Wine Region

The influence of terroir in determining wine sensory properties is supported by the specific grape microbiome and metabolome, which provide distinct regional wine characteristics. In this work, the metabolic composition of grapes, must and wine of the Syrah grape variety cultivated on two sites in the same region was investigated. Concomitantly, a sensorial analysis of the produced wines was performed. Ultra-high-resolution liquid chromatography coupled with tandem mass spectrometry (UHPLC-Q-ToF-MS/MS) was applied to identify grape and wine metabolites. Untargeted metabolomics was used to identify putative biomarkers for terroir differentiation. More than 40 compounds were identified, including 28 phenolic compounds and 15 organic acids. The intensity evolution of the analyzed chemical compounds showed similar behavior during the fermentation process in both terroirs. However, the metabolic analysis of the grape, must and wine samples enabled the identification of an anthocyanin, chrysanthemin, as a putative biomarker of terroir 1. The overall sensorial quality of the wines was also evaluated, and according to the hitherto reported results, the wines from site 1 scored better than the wines from site 2. The results highlight the potential of metabolomics to assess grape and wine quality, as well as terroir association.

Region, vintage, and grape maturity co-shaped the ionomic signatures of the Cabernet Sauvignon wines

The ionic elements in wine and in vineyards are gaining attention due to characterization of the wine traits, wine origin tracing, and vine nutrient judging. In this experiment, 19 elements were detected by inductively coupled plasma mass spectrometry (ICP-MS) in 69 wine samples from 4 regions, 3 vintages, and 3 grape maturity levels. Furthermore, the elements related to vine development, such as N, P, K, Ca, Mg, Cu, Fe, Zn and Cu in the vineyard soil and petioles were determined. Two orthogonal partial least squares discriminant analysis (O2PLS-DA) showed that K, Mn, Co, Sr, B, Si, Pb, Ni, Cu, and Zn were important elements in distinguishing the regions. High-temperature vintages can bring wines with high levels of Sr in wine. Na, Ca, K, Mg, Rb, Al, Rb, Pb and Fe can be used as signature elements to distinguish wines made from 2 grape maturities. And Cu, Zn, and Mn were the key elements used to differentiate the petioles in the 4 regions. Partial square regression (PLSR) analysis showed that soil pH was positively correlated with Al, B, Ba, K, Pb, Mn, Sr and Rb in wine, and K in wine was significantly positively correlated with element K in the soil. In conclusion, the elemental contents in wine are shaped by the combination of origin, vintage and grape maturity, while some key elements can be used as indicators of origin traceability.

Indigenous yeast can increase the phenolic acid and volatile ester compounds in Petit Manseng wine

Introduction

Indigenous yeasts are generally found in grapes, vineyards, and natural environments. Sequential inoculation and fermentation with non-Saccharomyces cerevisiae yeast (H30) and Saccharomyces cerevisiae (YT13) also improve the flavor of wine.

Methods

This study sequentially inoculated fermented Petit Manseng and natural grape juice with native H30 and YT13 selected from vineyards in Yantai, China.

Results and discussion

The sensory characteristics of Petit Manseng wine were evaluated by detecting the primary organic acids, phenolic acid compounds, and volatile ester compounds. The results showed that the lactic acid content of the natural wine fermented sequentially with H30 and YT13 increased by 490 μg/L compared with the control group, while the ferulic acid content was 1.4 times that of the single-yeast fermentation group. Furthermore, butyrolactone and anthocyanidin propionate were present in the mixed fermentation group, increasing the aroma complexity of Petit Manseng wine and providing high-quality yeast resources that increase the regional characteristics when producing dry white wine.

Characterization of Berry Skin Phenolic Profiles in Dalmatian Grapevine Varieties

Dalmatian vineyards host many autochthonous varieties. The phenolic profile, defined by the relative proportions of different phenolic compounds, is specific for each grape variety. The aim of this study was to determine and analyze the flavonoid compounds of twenty rare red grape varieties. Nineteen phenolic compounds, represented by anthocyanins, flavanols, and flavonols, were detected and quantified using HPLC in three consecutive vintages. The content of grape skin anthocyanins (10414.06 (Plavac mali crni)-19.58 (Trišnjavac) mg kg−1 d.w. of grape skin), flavonols (1742.08 (Pošip crni)-215.56 (Crljenak viški) mg kg−1 d.w. of grape skin), and flavan-3-ols (448.04 (Pošip crni)-87.88 (Glavinuša) mg kg−1 d.w. of grape skin) showed significant differences in investigated varieties. According to the investigated phenolic compounds, Pošip crni, Ljutun, Zadarka, Dobričić, Plavac mali crni, and Trnjak differed from other investigated varieties. These local varieties can be perceived as an alternative to widespread varieties in Dalmatia. This was shown by one of the first studies on phenolic profiles of (mostly) rare autochthonous varieties.

Archeochemistry reveals the first steps into modern industrial brewing

A historical beer, dated to the German Empire era, was recently found in northern Germany. Its chemical composition represents a unique source of insights into brewing culture of the late nineteenth century when pioneer innovations laid the foundations for industrial brewing. Complementary analytics including metabolomics, microbiological, sensory, and beer attribute analysis revealed its molecular profile and certify the unprecedented good storage condition even after 130 years in the bottle. Comparing its chemical signature to that of four hundred modern brews allowed to describe molecular fingerprints teaching us about technological aspects of historical beer brewing. Several critical production steps such as malting and germ treatment, wort preparation and fermentation, filtration and storage, and compliance with the Bavarian Purity Law left detectable molecular imprints. In addition, the aging process of the drinkable brew could be analyzed on a chemical level and resulted in an unseen diversity of hops- and Maillard-derived compounds. Using this archeochemical forensic approach, the historical production process of a culturally significant beverage could be traced and the ravages of time made visible.

Sulfonation Reactions behind the Fate of White Wine’s Shelf-Life

White wine’s oxidative stability after several years of bottle aging is synonymous to its organoleptic quality. In order to gain control over the cascade of chemical reactions that are implicated in that phenomenon, fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS)-based metabolomics and sensory evaluation were combined for the analysis of a vertical series of white wines from different vineyard plots. Data mining using supervised cluster analysis allowed the extraction of known and unknown sulfur- and nitrogen-containing molecular features, with oxidative stability molecular markers presenting an increased number of S and O atoms in their formulas. In their majority, S-containing molecular features possessed between 4 to ~12 O atoms, indicating the relatively higher importance of sulfonation reactions as opposed to dimerization reactions. Molecular networking, based on sulfonation reaction transformations, evidences the importance of hitherto unknown and/or minor sulfur dioxide binders (peptides, aldehydes, and polyphenols) on wine’s oxidative stability.

A Practitioner's Dilemma Mass Spectrometry-Based Annotation and Identification of Human Plasma and Urinary Polyphenol Metabolites

The practitioner's dilemma in metabolite assignment can be described as follows: For compound and metabolite identification, should we follow strict guidelines using authentic standards only, or should we accept uncertainties in structure assignment of compounds with the certainty of consequential errors. These uncertainties arise due to limitation of software and databases in combination with the complexity of the human body fluid samples. This article is protected by copyright. All rights reserved.

Non-Targeted Metabolomic Analysis of the Kombucha Production Process

Kombucha is a traditional fermented beverage obtained from the transformation of sugared black tea by a community of yeasts and bacteria. Kombucha production recently became industrialized, but its quality standards remain poorly defined. Metabolomic analyses were applied using FT-ICR-MS to characterize the impacts of production phases and the type of tea on the non-volatile chemical composition of kombucha. Independently from tea type, the first phase of acidification in open vessel was characterized by the release of gluconate and gallate from acetic acid bacteria metabolism and probably from polymeric polyphenols, respectively. The second phase of carbonation in closed vessel induced a consumption or transformation of oleic acid that could be consecutive of oxygen limitation. The first phase had the most impact on molecular diversity, but tea type mainly influenced the global composition in polyphenol profile. Black tea polyphenols were more impacted by microbial activity compared to green tea polyphenols.

Flavor Chemical Profiles of Cabernet Sauvignon Wines: Six Vintages from 2013 to 2018 from the Eastern Foothills of the Ningxia Helan Mountains in China

The eastern foothills of the Helan Mountains in the Ningxia region (Ningxia), is a Chinese wine-producing region, where Cabernet Sauvignon is the main grape cultivar; however, little compositional or flavor information has been reported on Ningxia wines. Oenological parameters, volatile profiles, and phenolic profiles were determined for 98 Ningxia Cabernet Sauvignon wines from the 2013–2018 vintages, as well as 16 from Bordeaux and California, for comparison. Ningxia wines were characterized by high ethanol, low acidity, and high anthocyanin contents. Multivariate analysis revealed that citronellol and 12 characteristic phenolic compounds distinguish Ningxia wines from Bordeaux and California wines. The concentrations of most phenolic compounds were highest in the 2018 Ningxia vintage and decreased with the age of the vintage. To our knowledge, this is the first extensive regionality study on red wines from the Ningxia region.

Elucidation of the non-volatile fingerprint in oven headspace vapor from bread roll baking by ultra-high resolution mass spectrometry

Untargeted research on vapor arising during the thermal processing of food has so far focused on volatile aroma compounds. In this study, we present an oven atmosphere sampling strategy to trap headspace aerosols along with semi- and non-volatile molecules liberated during the baking of wheat bread rolls. The collected vapor condensate was analyzed for its molecular fingerprinting using direct infusion ultra-high resolution mass spectrometry. We detected up to 4,700 molecular species in a vapor sample from bread rolls baked at 230 °C for 15 min. Beyond the global profiling of the underlying matrix, our method can follow complex reaction cascades during the baking process, such as the formation of advanced glycation end-products like maltosine through the interface of trapped vapor. Further, process parameters such as baking temperature and duration were used to model the dynamic liberation of molecules to the oven atmosphere by a response surface methodology approach.

Charting Shifts in Saccharomyces cerevisiae Gene Expression across Asynchronous Time Trajectories with Diffusion Maps

During fermentation, Saccharomyces cerevisiae metabolizes sugars and other nutrients to obtain energy for growth and survival, while also modulating these activities in response to cell-environment interactions. Here, differences in S. cerevisiae gene expression were explored over a time course of fermentation and used to differentiate fermentations, using Pinot noir grapes from 15 unique sites. Data analysis was complicated by the fact that the fermentations proceeded at different rates, making a direct comparison of time series gene expression data difficult with conventional differential expression tools. This led to the development of a novel approach combining diffusion mapping with continuous differential expression analysis (termed DMap-DE). Using this method, site-specific deviations in gene expression were identified, including changes in gene expression correlated with the non-Saccharomyces yeast Hanseniaspora uvarum, as well as initial nitrogen concentrations in grape musts. These results highlight novel relationships between site-specific variables and Saccharomyces cerevisiae gene expression that are linked to repeated fermentation outcomes. It was also demonstrated that DMap-DE can extract biologically relevant gene expression patterns from other contexts (e.g., hypoxic response of Saccharomyces cerevisiae) and offers advantages over other data dimensionality reduction approaches, indicating that DMap-DE offers a robust method for investigating asynchronous time series gene expression data.

LC-MS based metabolomic approach for the efficient identification and relative quantification of bioavailable cocoa phenolics in human urine

This study was designed to investigate the rate and extent of urinary excretion of cocoa phenolic metabolites after human intake using metabolomics approach. In this context, a feeding trial was conducted where urine samples were collected at different time points over 48-h period. Several biomarkers were highlighted in LC-MS based chemometrics using principal component (PCA) and partial least squares discriminant analysis (PLS-DA), which revealed the presence of both epicatechin and gut microbial phenyl-γ-valerolactones (PVLs) conjugated analogues. The presences of these metabolites segregated and grouped the samples based on cocoa and non-cocoa ingestion. Furthermore, semi quantification of major bioavailable metabolites was performed to determine the interindividual differences and assess the relative bioavailability of cocoa compounds in the human body. Our approach presented here is unique in displaying a combination of LC-MS based chemometrics visualization strategies, which revealed and identified significant biomarkers that could reduce the problems associated with data screening complexity.

Impact of Commercial Yeasts on Phenolic Profile of Plavac Mali Wines from Croatia

Wine quality is influenced by the presence of over 500 different chemical compounds, with polyphenols having a crucial role in color intensity and tonality, astringency, mouthfeel, and overall impression formation, especially in red wine production. Their concentrations in wine can vary notably depending on the grape variety, the temperature and the length of maceration process, aging duration, and yeast selection. Therefore, in this work, the main goal was to determine the influence of five commercially available Saccharomyces yeasts provided from Lallemand, France and AEB, Italy, on the phenolic compound composition and chromatic parameters of Plavac mali wines produced from the grapes from coastal Dalmatia, grown at two different micro-locations. The achieved results pointed out the marked difference in individual polyphenol compound adsorption between tested yeasts. Fermol Super 16 was the one with the lowest and Lalvin D21 the strongest adsorption ability, regardless of vine growing location. These differences can be explained by the content of some anthocyanins (delphinidin and petunidin-3-O-glucoside) and gallic acid, and some flavan-3-ols. Tested strains also influenced wine color intensity, pointing out the possibility of modulating the style of a Plavac mali by the use of commercial yeasts.

Saccharomyces cerevisiae Gene Expression during Fermentation of Pinot Noir Wines at an Industrially Relevant Scale

This study characterized Saccharomyces cerevisiae RC212 gene expression during Pinot noir fermentation at pilot scale (150 liters) using industry-relevant conditions. The reported gene expression patterns of RC212 are generally similar to those observed under laboratory fermentation conditions but also contain gene expression signatures related to yeast-environment interactions found in a production setting (e.g., the presence of non-Saccharomyces microorganisms).

Saccharomyces cerevisiae metabolism produces ethanol and other compounds during the fermentation of grape must into wine. Thousands of genes change expression over the course of a wine fermentation, allowing S. cerevisiae to adapt to and dominate the fermentation environment. Investigations into these gene expression patterns previously revealed genes that underlie cellular adaptation to the grape must and wine environments, involving metabolic specialization and ethanol tolerance. However, the majority of studies detailing gene expression patterns have occurred in controlled environments that may not recapitulate the biological and chemical complexity of fermentations performed at production scale. Here, an analysis of the S. cerevisiae RC212 gene expression program is presented, drawing from 40 pilot-scale fermentations (150 liters) using Pinot noir grapes from 10 California vineyards across two vintages. A core gene expression program was observed across all fermentations irrespective of vintage, similar to that of laboratory fermentations, in addition to novel gene expression patterns likely related to the presence of non-Saccharomyces microorganisms and oxygen availability during fermentation. These gene expression patterns, both common and diverse, provide insight into Saccharomyces cerevisiae biology critical to fermentation outcomes under industry-relevant conditions.

IMPORTANCE This study characterized Saccharomyces cerevisiae RC212 gene expression during Pinot noir fermentation at pilot scale (150 liters) using industry-relevant conditions. The reported gene expression patterns of RC212 are generally similar to those observed under laboratory fermentation conditions but also contain gene expression signatures related to yeast-environment interactions found in a production setting (e.g., the presence of non-Saccharomyces microorganisms). Key genes and pathways highlighted by this work remain undercharacterized, indicating the need for further research to understand the roles of these genes and their impact on industrial wine fermentation outcomes.

Two Sides to One Story-Aroma Chemical and Sensory Signature of Lugana and Verdicchio Wines

Lugana and Verdicchio are two Italian white wines with a Protected Designation of Origin (PDO) label. These two wine types are produced in different regions using the same grape variety. The aim of this work is to investigate the existence of volatile chemical markers that could help to elucidate differences between Lugana and Verdicchio wines both at chemical and sensory levels. Thirteen commercial wine samples were analyzed by Gas Chromatography-Mass Spectrometry (GC-MS), and 76 volatile compounds were identified and quantified. Verdicchio and Lugana had been differentiated on the basis of 19 free and glycosidically bound compounds belonging to the chemical classes of terpenes, benzenoids, higher alcohols, C₆ alcohols and norisoprenoids. Samples were assessed by means of a sorting task sensory analysis, resulting in two clusters formed. These results suggested the existence of 2 product types with specific sensory spaces that can be related, to a good extend, to Verdicchio and Lugana wines. Cluster 1 was composed of six wines, 4 of which were Lugana, while Cluster 2 was formed of 7 wines, 5 of which were Verdicchio. The first cluster was described as “fruity”, and “fresh/minty”, while the second as “fermentative” and “spicy”. An attempt was made to relate analytical and sensory data, the results showed that damascenone and the sum of 3 of esters the ethyl hexanoate, ethyl octanoate and isoamyl acetate, was characterizing Cluster 1. These results highlighted the primary importance of geographical origin to the volatile composition and perceived aroma of Lugana and Verdicchio wines.

Untargeted lipidomic approach in studying pinot noir wine lipids and predicting wine origin

An untargeted lipidomic profiling approach based on ultra - performance liquid chromatography - time-of-flight tandem mass spectrometry (UPLC-TOF-MS/MS) was successfully used to study the origin of commercial Pinot noir wines. The total wine lipids were extracted using a modified Bligh-Dyer method. In all wine samples, the total lipids were less than 0.1% (w/w) of wine. The wines analyzed consisted of 222 lipids from 11 different classes. 48 commercial Pinot noir wine samples were collected from producers in Burgundy, California, Oregon, and New Zealand. Lipidomic data was studied using advanced multivariate analysis methods, random forest, k-nearest neighbor (k-NN), and linear discriminant analysis. The overall classification accuracy was 97.5% for random forest and 90% for k-NN. Wine lipids showed a strong potential for classifying wines by origin, with the top 58 lipids contributing to the discrimination. This information could potentially be used for further study of the impacts of lipids on wine characteristics and authenticity.

Cocoa origin classifiability through LC-MS data: A statistical approach for large and long-term datasets

Classification of food samples based upon their countries of origin is an important task in food industry for quality assurance and development of fine flavor products. Liquid chromatography -mass spectrometry (LC-MS) provides a fast technique for obtaining in-depth information about chemical composition of foods. However, in a large dataset that is gathered over a period of few years, multiple, incoherent and hard to avoid sources of variations e.g., experimental conditions, transportation, batch and instrumental effects, etc. pose technical challenges that make the study of origin classification a difficult problem. Here, we use a large dataset gathered over a period of four years containing 297 LC-MS profiles of cocoa sourced from 10 countries to demonstrate these challenges by using two popular multivariate analysis methods: principal component analysis (PCA) and linear discriminant analysis (LDA). We show that PCA provides a limited separation in bean origin, while LDA suffers from a strong non-linear dependence on the set of compounds. Further, we show for LDA that a compound selection criterion based on Gaussian distribution of intensities across samples dramatically enhances origin clustering of samples thereby suggesting possibilities for studying marker compounds in such a disparate dataset through this approach. In essence, we show and develop a new approach that maximizes, avoiding overfitting, the utility of multivariate analysis in a highly complex dataset.

Metabolomic understanding of the difference between unpruning and pruning cultivation of tea (Camellia sinensis) plants

Tea (Camellia sinensis) leaf quality depends on several factors such as plucking seasons, cultivation practices, and climatic conditions, which affect the chemical compositions of tea leaves. Pruning has been practiced as one of the common cultivation managements in tea cultivation and is hypothesized to exhibit metabolic differences from unpruned tea plants. Although metabolomics studies provide immense information about production of distinct tea products, the metabolic physiology of the plants cultivated under unpruning conditions is poorly understood. Therefore, in the present study, we explored the metabolic characteristics of tea leaves obtained from unpruned tea plants collected at different plucking seasons in a single year and in a given plucking time in the three successive years, through ¹H NMR-based metabolomics approach. Seasonal variations in diverse tea leaf metabolites both in pruned and unpruned tea plants were observed along with marked metabolic differences in tea leaves collected from pruned and unpruned tea plants in a given plucking time. Particularly, in abnormal year of vintage with high rainfall in 2018, high synthesis of glucose followed by high accumulations of catechin, including its derivatives, in unpruned tea, demonstrated intense active photosynthesis compared to pruned tea plants, indicating different metabolic responses of pruned and unpruned tea plants to similar climatic conditions. The current study highlights the important role of tea cultivation practices in tea plants for better management of leaf quality and the strong metabolic dependence on climatic conditions in a given vintage.

Terroir and vintage discrimination of Malbec wines based on phenolic composition across multiple sites in Mendoza, Argentina

This study evaluated the phenolic profiles of Malbec wines made from grapes of 23 parcels distributed in 12 geographical indications (GIs) from Mendoza, Argentina. Wines were elaborated under standardized winemaking conditions over three consecutive vintages (2016–2018). Data discriminated wines from different GIs and parcels, based on an integrative data analysis by chemometric tools. Vintage effect and specific phenolic compounds were associated with some GIs or parcels. As well, regional climate conditions allowed partial discrimination of the GIs (and also some parcels). A random forest analysis correctly identified 11 out of 23 individual parcels across the different vintages. The most notorious compounds associated with such classification were p-coumaric acid, delphinidin-3-O-glucoside, caffeic acid, quercetin and peonidin-3-O-glucoside. The presented research allows to individualize, through phenolic profiles, parcels with unique characteristics over years. This is the first report characterizing Malbec wines coming from several GIs (and individual parcels) in different vintages. These results are strongly related to terroir features of wines, contributing to a better communication to consumers and to position Argentinean wines.

Comparison of Pyrolysis Liquids from Continuous and Batch Biochar Production—Influence of Feedstock Evidenced by FTICR MS

Bio-oils from biomass pyrolysis can be a resource for upgrading to chemicals or fuels. Here, for the first time, we compare the composition of bio-oils produced from two feedstocks (wheat straw, softwood) in pyrolysis units of different mode of operation (continuous—rotary kiln vs. batch) using Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) in different ionization modes (APPI (+), ESI (+/−)). Our results demonstrate that the pyrolysis unit design had only a minor influence on the composition of bio-oils produced from low-mineral containing wood biomass. Yet, the wheat straw-derived bio-oil produced in the continuous unit comprised lower molecular weight compounds with fewer oxygen-containing functional groups and lower O/C and H/C ratios, compared to bio-oils from batch pyrolysis. Longer residence time of vapours in the heated zone in the rotary kiln and a higher mineral content in wheat straw resulted in increased catalytically-mediated secondary reactions that favoured further bio-oil decomposition. This work shows for the first time that it is possible to produce distinct bio-oils without the need for external catalyst addition, by matching reactor type/design and feedstock.

Terroir Effect on the Phenolic Composition and Chromatic Characteristics of Mencía/Jaen Monovarietal Wines: Bierzo D.O. (Spain) and Dão D.O. (Portugal)

‘Mencía’/‘Jaen’ it’s an important red grape variety, exclusive of the Iberian Peninsula, used in wine production namely in Bierzo D.O. and Dão D.O., respectively. This work evaluates the effect of the two different “terroirs” on the phenolic composition and chromatic characteristics of ‘Mencía’/‘Jaen’ monovarietal wines produced at an industrial scale in the same vintage. Using Principal Component Analysis (PCA), Partial Least Squares-Discrimination Analysis (PLS-DA), and Orthogonal PLS-DA (OPLS-DA) it was found that peonidin-3-coumaroylglucoside, petunidin-3-glucoside, malvidin-3-coumaroylglucoside, peonidin-3-glucoside, malvidin-3-acetylglucoside, malvidin-3-glucoside, and ferulic acid were the phenolic compounds with the highest differences between the two regions. PLS regression allowed to correlate the differences in lightness (L*) and redness (a*) of wines from ‘Jaen’ and ‘Mencía’ to differences in colored anthocyanins, polymeric pigments, total pigments, total anthocyanins, cyanidin-3-acetylglucoside, delphinidin-3-acetylglucoside, delphinidin-3-glucoside, peonidin-3-coumaroylglucoside, petunidin-3-glucoside and malvidin-3-glucoside in wines, and the colorless ferulic, caffeic, and coutaric acids, and ethyl caffeate. The wines a* values were more affected by colored anthocyanins, ferulic acid, total anthocyanins, delphinidin-3-acetylglucoside, delphinidin-3-glucoside and petunidin-3-acetylglucoside, and catechin. The positive influence of ferulic acid in the a* values and ferulic, caffeic, coutaric acids, and ethyl caffeate on the L* values can be due to the co-pigmentation phenomena. The higher dryness and lower temperatures during the September nights in this vintage might explain the differences observed in the anthocyanin content and chromatic characteristics of the wines.

Water-Based Extraction of Bioactive Principles from Blackcurrant Leaves and Chrysanthellum americanum: A Comparative Study

The water-based extraction of bioactive components from flavonoid-rich medicinal plants is a key step that should be better investigated. This is especially true when dealing with easy-to-use home-made conditions of extractions, which are known to be a bottleneck in the course for a better control and optimization of the daily uptake of active components from medicinal plants. In this work, the water-based extraction of Blackcurrant (Ribes nigrum) leaves (BC) and Chrysanthellum americanum (CA), known to have complementary pharmacological properties, was studied and compared with a previous work performed on the extraction of Hawthorn (Crataegus, HAW). Various extraction modes in water (infusion, percolation, maceration, ultrasounds, microwaves) were compared for the extraction of bioactive principles contained in BC and CA in terms of extraction yield, of amount of flavonoids, phenolic compounds, and proanthocyanidin oligomers, and of UHPLC profiles of the extracted compounds. The qualitative and quantitative aspects of the extraction, in addition to the kinetic of extraction, were studied. The optimized easy-to-use-at-home extraction protocol developed for HAW was found very efficient to easily extract bioactive components from BC and CA plants. UHPLC-ESI-MS and high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) were also implemented to get more qualitative information on the specific and common chemical compositions of the three plants (including HAW). Their antihyaluronidase, antioxidant, and antihypertensive activities were also determined and compared, demonstrating similar activities as the reference compound for some of these plants.

Impact of grapevine red blotch disease on primary and secondary metabolites in 'Cabernet Sauvignon' grape tissues

The grapevine red blotch disease (GRBD) was first noticed in 2008, impacting grape ripening. In general, GRBD reduces grape and wine quality resulting in significant economic losses. The purpose of the present study was to evaluate the effect of GRBD on agronomical parameters of 'Cabernet Sauvignon' vines at harvest. Using a metabolomics approach, the influence on primary and secondary metabolite profiling in skin + pulp/flesh and seeds were also determined. GRBD influenced °Brix and berry weight, as well as primary and secondary metabolites in both tissues. 1D ¹H NMR was effective in quantifying the main primary and secondary metabolites affected by GRBD. RP-HPLC was similarly able to quantify the main phenolics affected. Multivariate analysis showed the influence of the virus on grape metabolites using both tools in two berry tissues. The effectiveness of both tools to describe sample variability was compared and the most affected metabolites in each tissue could be identified.

Volatile Profile Characterization of Croatian Commercial Sparkling Wines

Commercial sparkling wine production represents a relatively low but important part of the Croatian wine production, especially in the Zagreb county. This study presents the results of volatile aroma compounds profile and organic acid composition of commercial sparkling wine samples from three vine-growing regions in Zagreb county. In total, 174 volatile aroma compounds were identified, separated between their chemical classes (aldehydes, higher alcohols, volatile phenols, terpenes, C13-norisoprenoids, lactones, esters, fatty acids, sulfur compounds, other compounds, other alcohols). Higher alcohols such as phenylethyl and isoamyl alcohol as well as 2-methyl-1-butanol, and esters such as diethyl succinate, ethyl hydrogensuccinate, and ethyl lactate had the strongest impact on the volatile compounds profile of Zagreb county sparkling wine. The presence of diethyl glutarate and diethyl malonate, compounds whose concentrations are influenced by yeast autolysis or caused by chemical esterification during the ageing process, was also noted. The influence of every single volatile aroma compound was evaluated by discriminant analysis using forward stepwise model. The volatile profiles of traditional sparkling wines from Croatia were presented for the first time. It is hoped the results will contribute to better understanding the quality potential and to evaluate possible differences on the bases of detected aroma concentrations and multivariate analysis.

Mass spectrometry-based metabolomics for an in-depth questioning of human health

Today, metabolomics is becoming an indispensable tool to get a more comprehensive analysis of complex living systems, providing insights on multiple aspects of physiology. Although its application in large scale population-based studies is very challenging due to the processing of large sample sets as well as the complexity of data information, its potential to characterize human health is well recognized. Technological advances in metabolomics pave the way for the efficient biomarker discovery of disease etiology, diagnosis and prognosis. Here, different steps of the metabolomics workflow, particularly mass spectrometry-based approaches, are discussed to demonstrate the potential of metabolomics to address biological questioning in human health. First an overview of metabolomics is provided with its interest in human health studies. Analytical development and advances in mass spectrometry instrumentation and computational tools are discussed regarding their application limits. Advancing metabolomics for applicability in human health and large-scale studies is presented and discussed in conclusion.

Regionality in Australian Pinot noir wines: A study on the use of NMR and ICP-MS on commercial wines

Wine quality and character are defined in part by the terroir in which the grapes are grown. Metabolomic techniques, such as nuclear magnetic resonance (NMR) spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS), are used to characterise wines and to detect wine fraud in other countries but have not been extensively trialled in Australia. This paper describes the use of ICP-MS and NMR to characterise a selection of Pinot noir wines. Wines from varying terroirs could be somewhat distinguished by their mineral content using principal component analysis (PCA). PCA was able to separate wines by their Australian states more clearly than by region. Metabolomic analysis of the wines using NMR did not find any correlations with climate/daytime temperatures, or region. An analysis of coinertia suggested that the two datasets were not redundant, and it is proposed that ICP-MS data is the most useful for determining regionality.

Trunk Girdling Increased Stomatal Conductance in Cabernet Sauvignon Grapevines, Reduced Glutamine, and Increased Malvidin-3-Glucoside and Quercetin-3-Glucoside Concentrations in Skins and Pulp at Harvest

Girdling is a traditional horticultural practice applied at fruit set or other phenological stages, and is used mostly as a vine management. In grapevines, it is used primarily for table grapes to improve berry weight, sugar content, color, and to promote early harvest. The objective of this study was to evaluate the effect of trunk girdling applied at veraison, in 'Cabernet Sauvignon' wine grapes (Vitis vinifera L.), on agronomical and physiological parameters during vine development from the onset of ripening (veraison) to harvest, and additionally to quantify the effect of girdling on primary and secondary metabolism. Girdling was applied 146 days after pruning (dap) at veraison, when berry sampling for metabolomics and agronomical evaluations commenced, with a further three sampling dates until harvest, at 156 dap (30% maturation, 10 days after girdling-dag), 181 dap (70% maturation, 35 dag), and 223 dap (commercial harvest, 77 dag). Skin/pulp and seed tissues were extracted separately and metabolomics was performed using one-dimensional proton nuclear magnetic resonance (1D 1H NMR) spectroscopy and high performance liquid chromatography (HPLC-DAD). At harvest, girdling significantly increased stomatal conductance (gs) in vines, decreased glutamine concentrations, and increased anthocyanin and flavonol concentrations in the skin/pulp tissues of grape berries. Berry weight was reduced by 27% from 181 dap to harvest, and was significantly higher in grapes from girdled vines at 181 dap. Sugars, organic acids, and other amino acids in skin/pulp or seeds were not significantly different, possibly due to extra-fascicular phloem vessels transporting metabolites from leaves to the roots. Using a metabolomics approach, differences between skin/pulp and seeds tissues were meaningful, and a greater number of secondary metabolites in skin/pulp was affected by girdling than in seeds. Girdling is a simple technique that could easily be applied commercially on vine management to improve berry color and other phenolics in 'Cabernet Sauvignon' grapes.

A review on the aroma composition of Vitis vinifera L. Pinot noir wines: origins and influencing factors

Vitis vinifera L. Pinot noir still wines are some of the most popular and expensive red wines in the world. Several research articles are reported in literature concerning the impacts of viticultural and enological practices, and vineyard location, on Pinot noir still wine aroma. This review summarizes the previous and latest literature pertaining to volatile compounds including esters, higher alcohols and C₁₃-norisoprenoids, and their effect on Pinot noir wine perceived aroma. Their origin and behavior are discussed, as well as their role in regional differentiation. The first part of this review paper presents an overview of volatile compounds that are usually found in Pinot noir still wines at concentrations higher than their odor detection threshold. The second part deals with studies pertaining to human inputs that impact on Pinot noir wine aroma profile such as viticulture and winemaking interventions. The role of the vineyard site is also revised. This review concludes by considering what further opportunities are available to researchers in this field for greater control over Pinot noir wine quality outcomes.

Vineyard calcium sprays shift the volatile profile of young red wine produced by induced and spontaneous fermentation

Calcium supplements have increasingly been used at pre-harvest stages for improving fruit firmness, aiming at mitigating environmental stress. However, as recent studies demonstrated that calcium modifies the polyphenolic profile of grape berries, we hypothesize in this study that it also affects wine volatile profile. In a two-year study, grapevines cv. "Vinhão" were sprayed with 2% CaCl₂ throughout the fruiting season, and musts were prepared at a laboratory scale. Musts from calcium-treated fruits contained higher calcium levels and less anthocyanins. Increased calcium content did not affect the course of fermentation induced with a S. cerevisiae starter inoculum, but impacted the course of spontaneous fermentations carried out by endogenous berry microflora. Several compounds associated to varietal and fermentative aromas were largely influenced by the calcium treatment. For instance, volatile phenols decreased, together with β-damascenone, benzaldehyde and γ-nonalactone, while several acetates and alcohols increased. Principal component analysis showed that the volatile profile of control wines produced by spontaneous fermentation substantially differed between replicates, but calcium treatment lowered replicate variability. Volatile profiles were also influenced by the vintage and fermentation type. The shift in wine volatile profile upon calcium treatment may be relevant from an oenological perspective.

Evaluation of Saccharomyces cerevisiae Wine Yeast Competitive Fitness in Enologically Relevant Environments by Barcode Sequencing

When a wine yeast is inoculated into grape juice the potential variation in juice composition that confronts it is huge. Assessing the performance characteristics of the many commercially available wine yeasts in the many possible grape juice compositions is a daunting task. To this end we have developed a barcoded Saccharomyces cerevisiae wine yeast collection to facilitate the task of performance assessment that will contribute to a broader understanding of genotype-phenotype relations. Barcode sequencing of mixed populations is used to monitor strain abundance in different grape juices and grape juice-like environments. Choice of DNA extraction method is shown to affect strain-specific barcode count in this highly related set of S. cerevisiae strains; however, the analytical approach is shown to be robust toward strain dependent variation in DNA extraction efficiency. Of the 38 unique compositional variables assessed, resistance to copper and SO₂ are found to be dominant discriminatory factors in wine yeast performance. Finally, a comparison of competitive fitness profile with performance in single inoculum fermentations reveal strain dependent correspondence of yeast performance using these two different approaches.

Optimizing Water-Based Extraction of Bioactive Principles of Hawthorn: From Experimental Laboratory Research to Homemade Preparations

Hawthorn (Crataegus) is used for its cardiotonic, hypotensive, vasodilative, sedative, antiatherosclerotic, and antihyperlipidemic properties. One of the main goals of this work was to find a well-defined optimized extraction protocol usable by each of us that would lead to repeatable, controlled, and quantified daily uptake of active components from hawthorn at a drinkable temperature (below 60 °C). A thorough investigation of the extraction mode in water (infusion, maceration, percolation, ultrasounds, microwaves) on the yield of extraction and the amount of phenolic compounds, flavonoids, and proanthocyanidin oligomers as well as on the Ultra High Performance Liquid Chromatography (UHPLC) profiles of the extracted compounds was carried out. High-resolution Fourier transform ion cyclotron resonance mass spectrometry was also implemented to discriminate the different samples and conditions of extraction. The quantitative and qualitative aspects of the extraction as well as the kinetics of extraction were studied, not only according to the part (flowers or leaves), the state (fresh or dried), and the granulometry of the dry plant, but also the stirring speed, the temperature, the extraction time, the volume of the container (cup, mug or bowl) and the use of infusion bags.

Detection of Biomedically Relevant Stilbenes from Wines by Mass Spectrometry

Stilbenes represent a class of compounds with a common 1,2-diphenylethylene backbone that have shown extraordinary potential in the biomedical field. As the most well-known example, resveratrol proved to have anti-aging effects and significant potential in the fight against cardiovascular diseases and some types of cancer. Mass spectrometry is an analytical method of critical importance in all studies related to stilbenes that are important in the biomedical field. From the discovery of new natural compounds and mapping the grape metabolome up to advanced investigations of stilbenes' potential for the protection of human health in clinical studies, mass spectrometry has provided critical analytical information. In this review we focus on various approaches related to mass spectrometry for the detection of stilbenes-such as coupling with chromatographic separation methods and direct infusion-with presentation of some illustrative applications. Clearly, the potential of mass spectrometry for assisting in the discovery of new stilbenes of biomedical importance, elucidating their mechanisms of action and quantifying minute quantities in complex matrices is far from being exhausted.

Volatile terpenoids, norisoprenoids and benzenoids as markers of fine scale vineyard segmentation for Corvina grapes and wines

In this study, the diversity existing at the very small scale of single vineyard parcels in volatile composition of grapes and wines from a single estate in the Valpolicella wine region has been studied. Corvina grapes from eight contiguous vineyards were used for the study and vinified with the same protocol. The compounds analyzed by GC-MS were representative of the terpenoid, norisoprenoid and benzenoid chemical families. Free and bound compounds analysis showed that differences between parcels were relatively small on grapes samples, whereas after fermentation larger differences between wine samples were highlighted. Multivariate statistical analysis of wine volatiles highlighted the existence of similarities between wine volatile profiles, which reflected to a good extent the geographical location of the corresponding vineyard parcels. The main drivers of this diversity were the monoterpene alcohols linalool, α-terpineol, linalool oxide; the benzenoids vanillin, ethyl vanillate and methyl vanillate; and the norisoprenoid β-damascenone. Wine from one vineyard parcel was not correctly classified, possibly due to the influence of the peculiar training system applied to this parcel. With aging the vineyard parcel geographical diversity was still reflected by the chemical diversity of wines, even if the separation was less fine. As many reactions occurred, some drivers of the diversity were changed after aging. They were benzenoids: ethyl vanillate, methyl vanillate and vanillin; the norisoprenoid 3-oxo-α-ionol; the terpenes linalool oxide, linalool, p-methane-1,8-diol, α-terpineol, and the precursors of nerol, geraniol, linalool.

Influence of cell-cell contact between L. thermotolerans and S. cerevisiae on yeast interactions and the exo-metabolome

Sequential fermentation of grape must inoculated with L. thermotolerans and then S. cerevisiae 24 h later (typical wine-making practice) was conducted with or without cell-cell contact between the two yeast species. We monitored cell viability of the two species throughout fermentation by flow cytometry. The cell viability of S. cerevisiae decreased under both conditions, but the decrease was greater if there was cell-cell contact. An investigation of the nature of the interactions showed competition between the two species for nitrogen compounds, oxygen, and must sterols. Volatile-compound analysis showed differences between sequential and pure fermentation and that cell-cell contact modifies yeast metabolism, as the volatile-compound profile was significantly different from that of sequential fermentation without cell-cell contact. We further confirmed that cell-cell contact modifies yeast metabolism by analyzing the exo-metabolome of all fermentations by FT-ICR-MS analysis. These analyses show specific metabolite production and quantitative metabolite changes associated with each fermentation condition. This study shows that cell-cell contact not only affects cell viability, as already reported, but markedly affects yeast metabolism.