Associations among Wine Grape Microbiome, Metabolome, and Fermentation Behavior Suggest Microbial Contribution to Regional Wine Characteristics.

UnlabelledRegionally distinct wine characteristics (terroir) are an important aspect of wine production and consumer appreciation. Microbial activity is an integral part of wine production, and grape and wine microbiota present regionally defined patterns associated with vineyard and climatic conditions, but the degree to which these microbial patterns associate with the chemical composition of wine is unclear. Through a longitudinal survey of over 200 commercial wine fermentations, we demonstrate that both grape microbiota and wine metabolite profiles distinguish viticultural area designations and individual vineyards within Napa and Sonoma Counties, California. Associations among wine microbiota and fermentation characteristics suggest new links between microbiota, fermentation performance, and wine properties. The bacterial and fungal consortia of wine fermentations, composed from vineyard and winery sources, correlate with the chemical composition of the finished wines and predict metabolite abundances in finished wines using machine learning models. The use of postharvest microbiota as an early predictor of wine chemical composition is unprecedented and potentially poses a new paradigm for quality control of agricultural products. These findings add further evidence that microbial activity is associated with wine terroirImportanceWine production is a multi-billion-dollar global industry for which microbial control and wine chemical composition are crucial aspects of quality. Terroir is an important feature of consumer appreciation and wine culture, but the many factors that contribute to terroir are nebulous. We show that grape and wine microbiota exhibit regional patterns that correlate with wine chemical composition, suggesting that the grape microbiome may influence terroir In addition to enriching our understanding of how growing region and wine properties interact, this may provide further economic incentive for agricultural and enological practices that maintain regional microbial biodiversity

Understanding Problem Fermentations – A Review

Despite advances in winemaking technology and improvements in fermentation control, problem alcoholic andmalolactic fermentations remain a major oenological concern worldwide. This is due to possible depreciation ofproduct quality and its consequent negative economic impact. Various factors have been identified and studied overthe years, yet the occurrence of fermentation problems persists. The synergistic effect of the various factors amongsteach other provides additional challenges for the study of such fermentations. This literature review summarisesthe most frequently studied causes of problematic alcoholic and malolactic fermentations and in addition provides asummary of established and some potential new analytical technologies to monitor and investigate the phenomenonof stuck and sluggish fermentations

Monitoring wine fermentation using ATR-MIR spectroscopy and chemometric techniques.

El vi és un dels productes amb valor afegit més apreciats al món i és per això que el control de la producció vinícola ha sigut sempre un tema prioritari per a la majoria dels cellers. La implementació d’anàlisis at-line com són les Tècniques Analítiques de Processos (PAT), no només permet un control del vi acabat si no que també dóna la possibilitat de prendre mesures correctives al llarg del procés evitant així obtenir un producte final defectuós. En aquesta tesi doctoral, es va investigar la possibilitat d’implementar diferents estratègies per controlar i detectar desviacions durant la fermentació alcohòlica utilitzant un equip portable i de resposta ràpida: un equip d’ espectroscòpia en l’infraroig mitjà, en el mode de reflectància total atenuada (ATR-MIR) el qual permet obtenir, en pocs segons, una gran quantitat d’informació sobre el procés de fermentació que es va tractar amb diferents tècniques quimiomètriques. Primer, utilitzant les dades espectrals i la regressió de mínims quadrats parcials, es van predir diferents paràmetres químics durant la fermentació alcohòlica. En segon lloc, es van comparar els espectres de fermentacions control amb fermentacions desviades utilitzant l’anàlisi discriminant per mínims quadrats parcialsEl vino es uno de los productos con valor añadido más apreciados del mundo y por ello, el control de la producción vinícola ha sido siempre un tema prioritario para la mayoría de bodegas. La implementación de análisis at-line como son las Técnicas Analíticas de Procesos (PAT), no sólo permite un control del vino acabado si no que también brinda la posibilidad de tomar medidas correctivas a lo largo del proceso evitando así obtener un producto final defectuoso. En esta tesis doctoral, se investigó la posibilidad de implementar diferentes estrategias para controlar y detectar desviaciones durante la fermentación alcohólica utilizando un equipo portátil y de respuesta rápida: un equipo de espectroscopia en el infrarrojo medio, en el modo de reflectancia total atenuada (ATR-MIR) el cual permite obtener, en pocos segundos, una gran cantidad de información sobre el proceso de fermentación que se trató con diferentes técnicas quimiométricas. Primero, usando los datos espectrales y la regresión de mínimos cuadrados parciales, se predijeron distintos parámetros químicos durante la fermentación alcohólica. En segundo lugar, se compararon los espectros de fermentaciones control con fermentaciones desviadas utilizando el análisis discriminante por mínimos cuadrados parcialesWine is one of the most appreciated high added-value products in the world and therefore, controlling wine production has always been a priority for most wineries. Implementing at-line analyses such as Process Analytical Technologies (PAT) guidelines, not only enables a control of the final wine but also gives the possibility to apply correcting measures throughout the process, thus avoiding a defective final product. In this doctoral thesis, we investigated the possibility of implementing different strategies to control and detect deviations during wine alcoholic fermentation using a fast and portable equipment: an Attenuated Total Reflectance Mid-Infrared (ATR-MIR) spectrometer which allows obtaining, in a few seconds, a large amount of information about the fermentation process, which was processed with different chemometric techniques. First, using the spectral data and Partial Least Square Regression, different chemical parameters were predicted during alcoholic fermentation. Secondly, we compared the spectra from both Normal Operation Conditions and deviated fermentations using Partial Least Squares Discriminant Analysis. ANOVA–simultaneous component analysis was applied to study the influence of several factors into the variance of the spectra. Multivariate Curve Resolution Alternating Least Squares was used to model both alcoholic and malolactic fermentations. Finally, a PAT methodolog

On-line monitoring of food fermentation processes using electronic noses and electronic tongues: A review

Fermentation processes are often sensitive to even slight changes of conditions that may result in unacceptable end-product quality. Thus, close follow-up of this type of processes is critical for detecting unfavorable deviations as early as possible in order to save downtime, materials and resources. Nevertheless the use of traditional analytical techniques is often hindered by the need for expensive instrumentation and experienced operators and complex sample preparation. In this sense, one of the most promising ways of developing rapid and relatively inexpensive methods for quality control in fermentation processes is the use of chemical multisensor systems. In this work we present an overview of the most important contributions dealing with the monitoring of fermentation processes using electronic noses and electronic tongues. After a brief description of the fundamentals of both types of devices, the different approaches are critically commented, their strengths and weaknesses being highlighted. Finally, future trends in this field are also mentioned in the last section of the article. (C) 2013 Elsevier B.V. All rights reserved.Peris Tortajada, M.; Escuder Gilabert, L. (2013). On-line monitoring of food fermentation processes using electronic noses and electronic tongues: A review. Analytica Chimica Acta. 804:29-36. doi:10.1016/j.aca.2013.09.048S293680

Espectroscopia de infravermelho com transformada de Fourier na monitorização da produção de vinho

ReviewThe complexity of the wine matrix makes monitoring of the winemaking process from the grapes to the final product crucial for the wine industry. In this context, analytical methodologies that can combine good accuracy, robustness, high sample throughput, “green character”, and by preference real-time analysis, are on-demand to create high-quality vitivinicultural products. In the last years, Fourier-transform Infrared Spectroscopy (FTIR) combined with chemometric analysis has been evaluated in several studies as an effective analytical tool for the wine sector. Some applications of FTIR spectroscopy have been already accepted by the wine industry, mainly for the prediction of basic oenological parameters, using portable and non-portable instruments, but still many others are waiting to be thoroughly developed. This literature review aims to provide a critical synopsis of the most important studies assessing grape and wine quality and authenticity, and to identify possible gaps for further research, meeting the needs of the modern wine industry and the expectations of most demanding consumers. The FTIR studies were grouped according to the main sampling material used - 1) leaves, stems, and berries; 2) grape must and wine applications - along with a summary of the basic limitations and future perspectives of this analytical techniqueA complexidade da matriz do vinho torna a monitorização da sua produção, desde a maturação da uva até o produto final, fundamental para a indústria do vinho. Neste contexto, metodologias analíticas com boa exactidão, robustez, elevado rendimento de amostras, menos penalizadoras para o meio ambiente, e se possível capazes de fornecer resultados em tempo real, são muito importantes para a obtenção de produtos vitivinícolas de alta qualidade. Nos últimos anos, a Espectroscopia de Infravermelho com Transformada de Fourier (FTIR) combinada com a análise quimiométrica tem sido avaliada em diversos estudos por ser uma ferramenta analítica apropriada para o setor vitivinícola. Algumas aplicações de FTIR já foram adoptadas pela indústria do vinho, principalmente para a predição de parâmetros enológicos básicos, através de instrumentos portáteis e não portáteis, mas há ainda um enorme potencial de desenvolvimento a explorar. A presente revisão da literatura tem como objetivo fornecer uma sinopse crítica dos estudos mais importantes realizados para avaliação da qualidade e autenticidade do vinho e identificar possíveis lacunas para investigação futura, indo ao encontro das necessidades da indústria vinícola moderna e das expectativas dos consumidores mais exigentes. Os estudos sobre FTIR foram agrupados de acordo com o principal material de amostragem - 1) folhas, engaços e bagos; 2) mostos e vinhos - juntamente com informação sobre as limitações básicas e perspectivas futuras desta técnica analíticainfo:eu-repo/semantics/publishedVersio

Natural white wine alcoholic fermentation: a focus on progression trajectories and sensory outcomes

Thesis (PhDAgric)--Stellenbosch University, 2021.ENGLISH ABSTRACT: Wine is the result of the impact of collective production decisions made from the vineyard and throughout the steps taken in the winery. Nowadays, consumers have access to wines from across the world. This has resulted in an elevated consumer-demand for wines that demonstrate, in sensorial terms, individuality, exceptional quality, and provenance. Wine producers interpret this hugely competitive market-pull through alternative winemaking strategies, such as natural or spontaneous fermentations, in the belief that wines produced in this way reflect uniqueness and authenticity. The sensory profile of a wine is hugely influenced by the fermentation regime chosen by the oenologist or winemaker. Alcoholic fermentation is the bioprocess whereby grape sugars, which mainly consist of glucose and fructose, are converted by yeasts to ethanol, CO2, and secondary metabolites. The sensory profiles of some white wine styles are largely determined by the grape flavour compounds and those derived during alcoholic fermentation. Alcoholic fermentation (AF) is, arguably, the most important step in winemaking and, therefore, the control and monitoring of this bioprocess is of the utmost importance for a predictable duration and outcome, as well as reproducibility from one vintage to the next. Fourier Transform mid-infrared (FT-MIR) spectroscopy is well implemented, in wine laboratories, for routine chemical analysis of alcoholic fermentation parameters. Extensive research exists for quantification calibration development using FT-MIR spectroscopy but only few studies where the FT-MIR spectra are used for qualitative calibrations. No studies for explorative data mining of the information-rich FT-MIR spectra of AF could be found. The visualisation of big data is receiving much attention. Visualisation of data using multivariate data analysis techniques, gives a clear idea of what the information means, it highlights trends, patterns, and outliers. In this study, the visualisation of AF process data is novel. Using Chardonnay grape must (Data set 1), fermented at a constant temperature and a three- by-three experimental design, it was possible to visualise the variation of the progression trajectories between the fermentations. The data consisted of FT-MIR spectra and chemical parameters which aids the interpretation of the progression trajectories. Statistical data analysis of the chemical parameters correlated with the visualisation of the FT-MIR spectral data and chemical parameters using multiway partial least square regression (MPLS) or batch evolution modeling (the term used in this study). PCA of the PLS scores of the BEM, the fermentations could be visually compared on the PCA score plot. Further to determine class separation by orthogonal PLS discriminant analysis (OPLS-DA) confirmed correlation and variation between the fermentations. The second data set (Data set 2) was historical, Chenin blanc, Colombard and Chardonnay fermentation data, from a commercial winery. The fermentations all fermented to dry (residual sugars < 5g/L). No prior knowledge existed of which yeasts were used, only that best fermentation practises were applied. The time trajectory of alcoholic fermentations varies greatly. To compare and monitor fermentations effectively the biological state at a certain point needs to be the same in relation to the process. A relative time scale was introduced in this study to realign the data and put it on a generic time basis. The PLS model with X- FT-MIR spectra and Y-relative time demonstrated significant statistical indicators. Concluding that relative time implemented in the multivariate model, ensures correct interpretation of the progression trajectories of a given point in time and that the prediction of fermentation time is possible. Natural or uninoculated fermentation introduces more variation within the FT-MIR spectral data. The reason being that these fermentations are not inoculated with a Saccharomyces cerevisiae yeast, as in the first two data sets. In natural fermentation, the grape must is fermented by the indigenous S. cerevisiae and non-Saccharomyces (NS) yeasts. Yeast-to-yeast interaction occurs which introduces more variation than an inoculated commercial yeast fermentation. It was important to compare the between variation of the different fermentations. The third data set (Data set 3), comprised of Sauvignon blanc, this global popular cultivar was chosen as a solid foundation exists due to previous research. Inoculated and natural fermentations on a micro- and commercial scale was performed. S. cerevisiae and Torulaspora delbrueckii was each inoculated in one small-scale fermentation, respectively. Two co-inoculation fermentations, the sequential inoculation strategy of T. delbrueckii and S. cerevisiae, as well as two natural fermentations were performed on small- and commercial-scale. FT-MIR spectroscopy spectral data was acquired during each of the fermentations, chemical parameters were determined through the calibrations from the FT120 Winescan, the chemical aroma compounds were measured as well as sensory profiling using sensory descriptive analysis method of the finished wines. Natural fermentations had lower fermentation kinetics and thus has a longer duration time than inoculated fermentations. BLM, with relative time (Y-variable) and the FT-MIR spectra (X-variables), visualised the variances between the fermentations. The S. cerevisiae inoculated fermentation was more different in comparison to the other fermentations. This was seen on the multivariate statistical control charts (MSPC) or batch control charts, as the fermentation sat well above the other fermentations which indicated higher fermentation kinetics. The PCA score plot of BEM also confirmed the variation visually. A point-to-point function on the MSPC charts demonstrated the loading weights for glucose, fructose, and ethanol, responsible for this variation. It was established that natural fermentation can also be monitored and compared in the same model as inoculated fermentations. PLS-Trees® , hierarchical classification method, was used to explore the within variation of the fermentation spectral data. Three data clusters were identified within the progression of inoculated fermentations. However, within the natural and co-inoculated fermentations four data clusters were identified. It could be speculated that more variation exists within the fermentation due to the longer fermentation time. The changing relationship of the FT-MIR spectra and chemical parameters between the clusters could be interpreted for insight, through the respective loading weights. A possible application will be that a local predictive model based on this insight will be more accurate, a lower standard error of calibration, than a global model. It was of interest to investigate if correlation exists between the BEM of the FT-MIR spectral fermentation data and the sensory descriptive and aroma compounds data of the corresponding finished wines. This was a three-data block comparison. Multiblock orthogonal component analysis (MOCA) finds the joint and unique variation between the data blocks. Joint variation and correlation were found between the three data blocks. No unique variation exists between the three data blocks. However, from the PCA score plot of the MOCA model observation C (small- scale co-inoculation) had larger variations between the three block models. Observation F (commercial-scale co-inoculation) had the least variation between the three block models. The other observations demonstrated similar variations. The reason for this could not be determined in this study and needs further research. The correlation between the three data blocks makes qualitative calibrations a possibility. The positive contribution is that qualitative outcomes could be possibly predicted during certain stages of alcoholic fermentation and encourages further research in this field.AFRIKAANSE OPSOMMING: Wyn is die resultaat van die impak van gesamentlike produksiebesluite wat geneem word in die wingerd en tydens die deurlopende stappe wat gevolg word in die wynkelder. Deesdae het verbruikers toegang tot wyne van dwarsoor die wêreld. Dit het gelei tot ‘n verhoogde verbruikersaanvraag na wyne wat, in sensoriese terme, individualiteit, uitstaande kwaliteit en oorspong demonstreer. Wynprodusente interpreteer hierdie uiters kompeterende markaanvraag deur alternatiewe wynmaakstrategieë, soos natuurlike of spontane fermentasies. Die mening word gehuldig dat wyn wat op hierdie manier geproduseer is, uniekheid en intrinsieke egtheid weerspieël. Die sensoriese profiel van ‘n wyn word grootliks beïnvloed deur die fermentasieregime wat die wynmaker gebruik. Alkoholiese fermentasie (AF) verwys na die proses waartydens die bioverwerking van druiwesuikers, wat hoofsaaklik bestaan uit glukose en fruktose, omgeskakel word deur giste tot etanol, CO2 en sekondêre metaboliete. Die sensoriese profiele van sekere witwynstyle word hoofsaaklik bepaal deur die geurverbindings wat in die druif self teenwoordig is, asook dié verbindings wat tydens AF gevorm word. Argumentsonthalwe, kan AF beskou word as die belangrikste stap in wynbereiding. Derhalwe is die beheer en monitering van hierdie bioproses noodsaaklik vir ‘n voorspelbare duurte en uitkoms van die fermentasies, asook vir herhaalbare uitkomste van die wynstyl van een oesjaar na die volgende. Fourier transformasie mid-infrarooi (FT-MIR) spektroskopie is goed gevestig in wynlaboratoriums vir die roetine analise van chemiese parameters wat ‘n aanduiding gee van die verloop van AF. Uitgebreide navorsing is reeds gedoen op die ontwikkeling van kwantitatiewe FT-MIR spektroskopie-gebaseerde kalibrasiemodelle, terwyl slegs enkele studies FT-MIR spektra gebruik het vir kwalitatiewe kalibrasies. Geen studies wat verkennende data-ontginning van die inligtingryke AF FT-MIR spektra kon in die literatuur gevind word nie. Die visualisering van groot datastelle met behulp van multi-veranderlike data analitiese (MVDA) tegnieke kry tans baie aandag. Die resultate wat met hierdie tegnieke verkry word, gee ‘n goeie aanduiding van die waarde van die inligting vervat in die data, deurdat tendense, patrone en ekstreme datapunte beklemtoon word. Die benadering wat in hierdie studie gebruik is om die AF proses te visualiseer, is ‘n eerste in hierdie vakdisipline. Met die gebruik van Chardonnay druiwe (Datastel 1), gefermenteer by 'n konstante temperatuur en met ‘n drie-by-drie eksperimentele ontwerp, was dit moontlik om die variansie van die progressietrajekte in die onderskeie fermentasies te visualiseer. Die data, bestaande uit FT- MIR spektra en chemiese parameters, het bygedra om die progressietrajekte te interpreteer. Statistiese data-analise van die chemiese parameters het gekorreleer met die visualisering van die FT-MIR spektrale data en chemiese parameters, met die gebruik van veelvoudige gedeeltelike minste kwadrate regressie (GMK) en Batch Evolution Modeling (BEM). Hoofkomponente-analise (HKA) van die GMK en BEM data is gebruik om die fermentasies visueel te vergelyk. Diskriminant analise deur middel van ortogonale GMK is ook geruik in die visualisering van die fermentasies. Datastel 2 was ‘n historiese AF datastel van Chenin Blanc, Colombard en Chardonnay, wat by ‘n kommersiële wynkelder gegenereer is. Al die fermentasies was droog gegis (oorblywende suikers <5g/L). Geen inligting oor watter giste gebruik is vir AF was beskikbaar nie; slegs dat die beste fermentasiepraktyke toegepas is. Omdat die tydsduurte van die onderskeie AF grootliks van mekaar verskil het, was dit nie moontlik om die biologiese status van die fermentasies op ‘n bepaalde tydstip met mekaar te vergelyk nie. Derhalwe is ‘n relatiewe tydskaal in hierdie studie bekendgestel om die data te belyn, en om dit op ‘n generiese tydbasis te plaas. ‘n GMK model met die FT-MIR spektra as X- veranderlikes en relatiewe tyd die Y-veranderlike, het beduidende statistiese verskille tussen die tydsduurtes van die onderskeie fermentasies getoon. Met die gebruik van relatiewe tyd, kon die korrekte interpretasie van die progressietrajekte op ‘n sekere tydstip gemaak word en was dit moonlik om die vordering van die fermentasies korrek te voorspel. Natuurlike of ongeïnokuleerde fermentasies het meer variansie in die FT-MIR spektrale data tot gevolg gehad. Die rede hiervoor was dat hierdie fermentasies nie geïnokuleerd was met die Saccharomyces cerevisiae wyngis nie. In natuurlike fermentasies, word die druiwemos gegis deur inheemse S. cerevisiae en nie-Saccharomyces (NS) giste wat natuurlik teenwoordig is in die druiwemos. Interaksie tussen die inheemse giste vind plaas wat meer variasie in die verloop van die fermentasie tot gevolg gehad het, as wat die geval was met die fermentasies wat met kommersiële giste geïnokuleer was. Datastel 3 het bestaan uit Sauvignon Blanc fermentasies. Hierdie wêreldwye gewilde kultivar is gekies omdat heelwat navorsing reeds op die kultivar gedoen is, en die effekte van verskillende inokulasiestrategieë teen so ‘n bekende agtergrond, duideliker ondersoek kon word. Geïnokuleerde en natuurlike fermentasies is uitgevoer op klein- en kommersiële skaal. S. cerevisiae en Torulaspora delbrueckii (T. delbrueckii) is elkeen onderskeidelik geïnokuleer in een klein-skaalse fermentasie. Twee ko-inokulasie strategië, naamlik opeenvolgende inokulasie van T.delbrueckii en S.cerevisiae, sowel as twee natuurlike fermentasies is uitgevoer op klein- en kommersiële skale. FT-MIR spektra is gegenereer tydens elk van die fermentasies. Chemiese parameters is bepaal deur die GMK kalibrasies van die FT120 Winescan spektrometer. Die chemiese aromaverbindings is gemeet deur gaschromatografie, terwyl die sensoriese profiele van voltooide wyne gegenereer is deur gebruik te maak van die sensoriese beskrywende analise metode. Natuurlike fermentasies het stadiger fermentasiekinetika getoon en het dus ‘n langer fermentastie-tyd gehad as geïnokuleerde fermentasies. BEM, met relatiewe tyd (Y-veranderlike) en die FT-MIR spektra (X-veranderlikes), het die variansie tussen die fermentasies gevisualiseer. Die S. cerevisiae geïnokuleerde fermentasie was meer verskillend, in vergelyking met die ander fermentasies. Dit is waargeneem in die Multi-veranderlike statistiese beheergrafieke (MSPC) en bundel beheergrafieke. Die PLS-trees® hierargiese klassifikasiemetode is gebruik om die interne variansie van die fermentasies met behulp van die spektrale data te ondersoek. Drie datagroepe is geïdentifiseer binne die geïnokuleerde fermentasies, terwyl vier datagroepe in die natuurlike en ko-geïnokuleerde fermentasies geïdentifiseer is. Dit kan bespiegel word dat meer variansie bestaan binne natuurlike en ko-geïnokuleerde fermentasies weens die langer tyd wat laasgenoemde fermentasie neem om te voltooi. Die veranderende verhouding tussen die FT- MIR spektra en chemiese parameters van die onderskeie groepe kon geinterpreteer word met behulp van MVDA tegnieke. ‘n Moontlike uitvloeisel van die bevinding is dat ‘n plaaslike prediksiemodel wat gebaseer is op gemete data, meer akkuraat kan wees, met ‘n laer standaard voorspellingsfout, as ‘n generiese model. Dit was van belang om vas te stel of daar ‘n korrelasie bestaan tussen die FT-MIR spektra, sensoriese data en chemiese aromakomponente van die ooreenstemmende voltooide wyne met behulp van ‘n drie-data blok vergelyking. Die Multiblock orthogonal component analysis (MOCA) tegniek is gebruik om die gesamentlike en unieke variansie tussen die datablokke te bereken. Gesamentlike variansie en korrelasie is gevind tussen die drie datablokke. Geen unieke variansie was egter in enige van die datablokke teenwoordig nie. Die kleinskaalse ko-geïnokuleerde fermentasie het die grootste variansie getoon tussen die drie datablokke, terwyl die kommersiële- skaal ko-inokulasie fermentasie die minste variansie tussen die drie datablokke getoon het. Die rede hiervoor kon nie in hierdie studie vasgestel word nie en verdere navorsing is nodig. Korrelasies wat gevind is tussen die drie datablokke maak kwalitatiewe kalibrasies ‘n moontlike opsie om te ondersoek. Die bydrae van die studie is dat kwalitatiewe uitkomste moontlik voorspel kan word gedurende sekere stadiums van alkoholiese fermentasie en dit moedig verdere navorsing in hierdie veld aan.Doctora

Fermentation with non-Saccharomyces yeasts as a novel biotechnology for berry wine production

Berries are rich in health-promoting bioactive components and berry consumption may be associated with a lower risk of various chronic diseases. However, only a fraction of the annual yield of berries is exploited and consumed. Development of berry wines may present an approach to increase the utilization of berries. The potential of non-Saccharomyces yeasts is increasingly recognized and explored in wine fermentation, whereas little has been done in berry wine production using non-Saccharomyces yeasts. Production of berry wines using non-Saccharomyces yeasts is a novel biotechnological approach for creating value-added products for the global market. The quality of berry wines is determined by the composition analysis, including the profile and content of both volatile and non-volatile compounds. Systematic research is needed to study the effects of non-Saccharomyces yeasts on the chemical composition of berry wines. In this work, our aim was to study inoculation with different yeast species/strains and fermentation methods on composition of bilberry (Vaccinium myrtillus L.) wines. The specific purposes were: 1) to characterize the volatile and/or non-volatile compositions of blue (BB) and white bilberries (WB) juices and their corresponding wines produced by conventional fermentation with Saccharomyces cerevisiae; 2) to study the effect of non-Saccharomyces yeast and inoculation type on the chemical profiles of BB wines; 3) to compare the dynamic changes in volatile compounds during alcoholic fermentation of BB wines using diverse non-Saccharomyces yeasts; 4) to monitor the evolutions of pyranoanthocyanins and their precursor anthocyanin monomers during aging of BB wines fermented with Saccharomyces and non-Saccharomyces yeasts. Volatile compounds were measured using headspace-solid phase microextraction gas chromatography-mass spectrometry methods. Non-volatile compounds of phenolic compounds were qualitatively and quantitatively analyzed using liquid chromatography coupled with a diode array detector and a mass spectrometer, while ethanol, sugars, and organic acids by gas chromatography-flame ionization detection. In BB juice, monomeric anthocyanins dominated among the phenolic compounds. Galactosides and glucosides delphinidin and cyanidin were the major anthocyanins among the 15 detected monomeric anthocyanins. Among the 42 nonanthocyanin phenolic compounds detected in BB and WB juices and wines, the levels of most individual compounds in nonpigmented bilberry products were significantly lower than those in pigmented ones. p-Coumaroyl monotropeins and quercetin glycosides both were the most predominant compounds in the groups of phenolic acids and flavonols, respectively, whereas the major flavan-3-ols were procyanidin B-type dimer and (−)-epicatechin. During fermentation with S. cerevisiae, the changes in content of nonanthocyanin phenolic compounds depended on the mutation of color. Fermentation significantly elevated the total contents of flavonol (TFO) and phenolic acids (TA) in WB samples. However, TA and TFO in BB juice showed a slight increase and reduction, respectively. The content of monomeric anthocyanins reduced considerably after fermentation. BB wines produced from pure, sequential, and simultaneous inoculations involving Schizosaccharomyces pombe 70572 possessed higher contents of total and most individual monomeric anthocyanins than those with Torulaspora delbrueckii and S. cerevisiae strains. Yeast fermentation significantly enhanced aroma intensity and volatile complexity of BB juice, particularly the groups of higher alcohols and esters. The contribution to volatile composition of bilberry wines was yeast and inoculation type dependent. Pure fermentations with T. delbrueckii and Metschnikowia pulcherrima strains were characterized by the high productions of higher alcohols, Saccharomycodes ludwigii by esters, and Zygosaccharomyces bailii by fatty acids, while fermentations with S. pombe, Hanseniaspora uvarum, and Issatchenkia orientalis strains yielded more off-flavor compounds than that with S. cerevisiae. Further improvements of aroma intensity were confirmed in sequential and simultaneous fermentations with S. cerevisiae and T. delbrueckii or S. pombe strains. Moreover, co-fermentation affected volatile profiles of particularly higher alcohols, esters, and carbonyl compounds of BB wines. In general, fermentation kinetics of non-Saccharomyces yeasts was less vigorous than that of S. cerevisiae as indicated by low ethanol production or poor sugar consumption. During fermentation, dynamic changes in volatile compounds were determined simultaneously with the development of ethanol concentration. There were also strain-dependent variations with regard to generation and degradation of volatile compounds. The content of monomeric anthocyanins in BB wines declined significantly during 12 months of aging, and a fraction of the reduction were formed vitisin A-type pyranoanthocyanins (vAPs). Fifteen vAPs were identified in aged bilberry wines. The high generation of pyruvic acid from the metabolism of S. pombe strains boosted the formation of vAPs in the wine products. The residual pyruvic acid in fresh bilberry wines consecutively reacted with anthocyanin monomers during aging, and the content of vAPs reached the maximum after 6 months of aging. Sugar moieties in monomeric anthocyanins affected the condensation reactions with pyruvic acid. Pyranoanthocyanins were more stable than their corresponding monomeric anthocyanins, therefore contributing to the stabilization of the color of the berry wines. Methylation in B-ring stabilized the structures of monomeric anthocyanins and pyranoanthocyanins.  Marjoissa on paljon terveydelle edullisia bioaktiivisia yhdisteitä ja marjojen käyttäminen voidaan yhdistää alempaan riskiin saada erilaisia kroonisia tauteja. Vain osa vuotuisesta marjasadosta kuitenkin hyödynnetään. Marjaviinien kehittäminen voi olla yksi mahdollinen tapa lisätä marjojen hyötykäyttöä. Saccharomyces-sukuun kuulumattomia hiivoja tarkastellaan ja käytetään kasvavissa määrin viinien valmistuksessa, mutta niiden hyödyntäminen marjaviineissä on ollut vähäistä. Saccharomyces-sukuun kuulumattomat hiivat marjaviinien valmistuksessa on uusi bioteknologinen lähestymistapa uusien lisäarvotuotteiden tuomisessa globaaleille markkinoille. Marjaviinien laatu voidaan määrittää haihtuvien ja haihtumattomien yhdisteiden koostumuksen ja pitoisuuksien analyyseilla. Systemaattisia tutkimuksia tarvitaan selvittämään Saccharomyces-sukuun kuulumattomien hiivojen vaikutuksesta marjaviinien kemialliseen koostumukseen. Tämän työn tavoitteena oli tutkia erilaisten hiivalajien, -kantojen ja käymismenetelmien vaikutusta mustikasta (Vaccinium myrtillus L.) valmistettujen viinien koostumukseen. Erityisinä tavoitteina oli: 1) karakterisoida sinisen (BB) ja valkoisen (WB) mustikkamehun ja niistä Saccharomyces cerevisiae -hiivalla valmistettujen marjaviinien haihtuvien ja haihtumattomien yhdisteiden koostumusta; 2) tarkastella Saccharomyces-sukuun kuulumattomien hiivojen ja hiivan ymppäystavan merkitystä mustikkaviinin (BB) kemiallisessa koostumuksessa; 3) vertailla Saccharomyces-sukuun kuulumattomilla hiivoilla valmistettujen mustikkaviinien (BB) haihtuvien yhdisteiden dynaamisia muutoksia käymisen aikana; 4) seurata pyranoantosyaniinien ja niiden monomeeristen antosyaniiniesiasteiden muodostumista Saccharomyces-sukuun kuuluvilla ja kuulumattomilla hiivoilla valmistettujen mustikkaviinien (BB) kypsymisen aikana. Haihtumattomia yhdisteitä mitattiin viinien ilmatilasta kiinteäfaasimikrouutolla ja kaasukromatografi–massaspektrometri-laitteistolla. Haihtumattomat fenoliset yhdisteet määritettiin laadullisesti ja määrällisesti nestekromatografilla yhdistettynä diodirividetektoriin ja massaspektrometriin, ja puolestaan etanoli, sokerit ja orgaaniset hapot määritettiin kaasukromatografi– liekki-ionisaatiodetektori-laitteistolla. Sinisessä mustikkamehussa monomeeriset antosyaniinit olivat merkittävin fenolisten yhdisteiden ryhmä. Delfinidiinin ja syanidiinin galaktosidit ja glukosidit olivat pääasiallisimmat antosyaniinit 15:n havaitun yhdisteen joukossa. Sinisistä (BB) ja valkoisista (WB) mustikkamehuista ja –viineistä määritettiin 42 antosyaniineihin kuulumatonta fenolista yhdistettä ja useampien niiden määrät olivat alhaisemmat pigmentoimattomissa tuotteissa kuin pigmentoiduissa. Kversetiinin glykosidit ja p-kumaroyylimonotropeiinit olivat merkittävimmät fenolisten happojen ja flavonolien yhdisteet näytteissä, kun taas prosyaniidien B-tyypin dimeeri ja (–)-epikatekiini olivat pääasiallisimmat flavan-3-oli-yhdisteet. S. cerevisiae -hiivakäymisen vaikutus näiden yhdisteiden koostumukseen oli riippuvainen marjan värin mutaatiosta: käyminen lisäsi flavonolien ja fenolisten happojen kokonaismäärää valkoisesta mustikasta valmistetuissa näytteissä. Sinisestä mustikasta valmistetuissa viineissä fenolisten happojen määrä kasvoi hieman, kun taas flavonolien määrä laski. Monomeeristen antosyaniinien määrä laski merkittävästi käymisen aikana. Mustikkaviineissä (BB), jotka valmistettiin ymppäämällä joko yksin, peräkkäin tai samanaikaisesti Schizosaccharomyces pombe -hiivan kantaa 70572, oli enemmän kokonaismäärältään antosyaniineja ja suurinta osaa yksittäisiä monomeerisia antosyaniineja verrattuna Torulaspora delbrueckii ja S. cerevisiae -hiivakantojen avulla valmistettuihin viineihin. Hiivakäyminen paransi merkitsevästi mustikkamehun aromien intensiteettiä ja haihtuvien yhdisteiden monimutkaisuutta vaikuttamalla erityisesti korkeampien alkoholien ja esterien yhdisteryhmiin. Haihtumattomien yhdisteiden merkitys oli riippuvaista hiivasta ja ymppäysmenetelmästä. Käyminen pelkillä T. delbrueckii and Metschnikowia pulcherrima -kannoilla sai aikaan korkeampien alkoholien määrän, kun taas Saccharomycodes ludwigii -hiivakannalla esterien määrä kasvoi ja Zygosaccharomyces bailii -hiivakannalla rasvahappojen määrä erottui muista. S. pombe, Hanseniaspora uvarum ja Issatchenkia orientalis –hiivakannoilla valmistetuissa näytteissä puolestaan esiintyi enemmän haittahajuiksi luokiteltavia yhdisteitä verrattuna S. cerevisiae -hiivakantaan. Aromien intensiteetin parantumista havaittiin myös näytteissä, joissa S. cerevisiae ja T. delbrueckii tai S. pombe -hiivakantoja lisättiin peräkkäisesti tai samanaikaisesti. Useamman hiivakannan ymppääminen yhdessä (peräkkäisesti tai samanaikaisesti) vaikutti erityisesti korkeampien alkoholien, esterien ja karbonyyliyhdisteiden profiileihin mustikkaviineissä. Saccharomyces-sukuun kuulumattomilla hiivoilla käymisen kinetiikka oli yleisesti hillitympi verrattuna S. cerevisiae -kantoihin, mikä havaittiin alhaisemmasta etanolin muodostumisesta ja huonommasta sokerien hyödyntämisestä. Haihtuvien yhdisteiden dynaamisia muutoksia tarkasteltiin samanaikaisesti etanolin määrän muodostumisen kanssa käymisen aikana. Näissä muutoksissa havaittiin myös hiivakannasta riippuvia haihtuvien yhdisteiden muodostumisia ja hajoamisia. Monomeeristen antosyaniinien yhdisteiden määrä mustikkaviineissä (BB) laski merkitsevästi 12 kuukauden kypsymisen aikana. Osa laskusta selittyi vitisiini A -tyypin pyranoantosyaniinien muodostumisella (vAP). Kypsytetyistä mustikkaviineistä havaittiin 15 vAP-yhdistettä. S. pombe -hiivakannan korkea palorypälehapon muodostuskyky paransi vAP-yhdisteiden muodostumista. Mustikkaviinien vapaa palorypälehappo reagoi monomeeristen antosyaniinien kanssa kypsymisen aikana ja vAP-yhdisteiden määrä saavutti huippunsa kuuden kuukauden kypsymisen kohdalla. Pyranoantosyaniinit olivat vakaampia verrattuna vastaaviin monomeerisiin antosyaniineihin vaikuttaen siten viinien värin säilyvyyteen. B-renkaan metylaatio vakautti monomeeristen antosyaniinien ja pyranoantosyaniinien rakenteita

Linking gene regulation and the exo-metabolome: A comparative transcriptomics approach to identify genes that impact on the production of volatile aroma compounds in yeast

BACKGROUND: 'Omics' tools provide novel opportunities for system-wide analysis of complex cellular functions. Secondary metabolism is an example of a complex network of biochemical pathways, which, although well mapped from a biochemical point of view, is not well understood with regards to its physiological roles and genetic and biochemical regulation. Many of the metabolites produced by this network such as higher alcohols and esters are significant aroma impact compounds in fermentation products, and different yeast strains are known to produce highly divergent aroma profiles. Here, we investigated whether we can predict the impact of specific genes of known or unknown function on this metabolic network by combining whole transcriptome and partial exo-metabolome analysis. RESULTS: For this purpose, the gene expression levels of five different industrial wine yeast strains that produce divergent aroma profiles were established at three different time points of alcoholic fermentation in synthetic wine must. A matrix of gene expression data was generated and integrated with the concentrations of volatile aroma compounds measured at the same time points. This relatively unbiased approach to the study of volatile aroma compounds enabled us to identify candidate genes for aroma profile modification. Five of these genes, namely YMR210W, BAT1, AAD10, AAD14 and ACS1 were selected for overexpression in commercial wine yeast, VIN13. Analysis of the data show a statistically significant correlation between the changes in the exo-metabome of the overexpressing strains and the changes that were predicted based on the unbiased alignment of transcriptomic and exo-metabolomic data. CONCLUSION: The data suggest that a comparative transcriptomics and metabolomics approach can be used to identify the metabolic impacts of the expression of individual genes in complex systems, and the amenability of transcriptomic data to direct applications of biotechnological relevance

Maturation of Moristel in Different Vineyards: Amino Acid and Aroma Composition of Mistelles and Wines with Particular Emphasis in Strecker Aldehydes

The aim of this article was to assess the influence of the harvest date on the composition of amino acids and derived aromatic compounds in grape-mistelle and wine of the Moristel variety, in different vineyards. Two vineyards were sampled in 2016 and another one in 2017. At each sampling point, grapes were collected, destemmed, crushed and divided into four aliquots. The first three were fermented, and the latter was treated with ethanol, to produce 1-week macerates containing 15% ethanol (v/v)-mistelles. Overall, 10 mistelles and 33 wines were produced. Amino acids, Strecker aldehydes and aroma compounds were analysed. Amino acid profiles are characteristic of the vineyard and level of ripeness, converging with maturation. In fermentation, major amino acids, except proline, are consumed at a relatively fixed and specific tax, while consumption of 13 amino acids is determined by the ratios of alanine, glutamic acid, serine and threonine, with γ-aminobutyric acid. After fermentation, amino acid precursors to Strecker aldehydes are maxima in unripe and overripe samples, while Strecker aldehydes are maxima in unripe wines. No direct correlations between precursor amino acids in mistelle and aromatic compounds in wine have been found. Nevertheless, must amino acid profiles could determine wine aroma composition

Detection and Quantification of Grapevine Bunch Rot Using Functional Data Analysis and Canonical Variate Analysis Biplots of Infrared Spectral Data

Grapevine bunch rot assessment has economic significance to wineries. Industrial working conditionsrequire rapid assessment methods to meet the time constraints typically associated with grape intakeat large wineries. Naturally rot-affected and healthy white wine grape bunches were collected overfive vintages (2013 to 2016, 2020). Spectral data of 382 grape must samples were acquired using threedifferent, but same-type attenuated total reflection mid-infrared (ATR-MIR) ALPHA spectrometers. Thepractical industrial problem of wavenumber shifts collected with different spectrometers was overcome byapplying functional data analysis (FDA). FDA improved the data quality and boosted data mining effortsin the sample set. Canonical variate analysis (CVA) biplots were employed to visualise the detection andquantification of rot. When adding 90 % alpha-bags to CVA biplots minimal overlap between rot-affected(Yes) and healthy (No) samples was observed. Several bands were observed in the region 1734 cm-1 to 1722cm-1 which correlated with the separation between rot-affected and healthy grape musts. These bandsconnect to the C=O stretching of the functional groups of carboxylic acids. In addition, wavenumber 1041cm-1, presenting the functional group of ethanol, contributed to the separation between categories (severity% range). ATR-MIR could provide a sustainable alternative for rapid and automated rot assessment.However, qualitative severity quantification of rot was limited to only discriminating between healthy andsevere rot (&gt; 40 %). This study is novel in applying FDA to correct wavenumber shifts in ATR-MIR spectraldata. Furthermore, visualisation of the viticultural data set using CVA biplots is a novel application of thistechnique