Wine Fermentation Research Articles

Influence of the use of sulfur dioxide, the distillation method, the oak wood type and the aging time on the production of brandies

Brandies are spirits produced from wine spirit and wine distillates. The original wines selected to be distilled to produce the wine spirits as well as the distillation method used determine, to a large extent, the organoleptic characteristics of the final products. The young wine spirits evolve during their aging in oak casks, this being another key stage that affects the chemical and sensorial characteristics of the final brandy. In this work, seven different brandies have been studied. They were obtained from wine produced with and without the addition of sulfur dioxide, during their fermentation, using different distillation methods (single, double or serial distillation using pot stills and continuous column distillation) and aged for 14 or 28 months in three different types of oak wood (Quercus alba, Quercus robur and Quercus petraea) previously toasted to two different grades (medium or light).The use of unsupervised pattern recognition methods (HCA and FA) determined that the addition of sulfur dioxide during the fermentation of the base wine has a major influence on the aromatic and phenolic profile of the aged distillates. On the other hand, by means of supervised pattern recognition methods such as LDA and ANNs, the most significant variables that would allow to discriminate between the classes of brandies identified in the study were evaluated. Thus, the results obtained should cast some light on the most significant variables to be taken into account regarding Brandy production processes if a better control over these production processes is to be achieved, so that more exclusive and better quality products are obtained.

Split batch and coculture fermentation to regulate the organic acids and flavor profile of fruit wine-a case study of Prunus mume Sieb. et Zucc (greengage) wine

The higher acidity in fruits compared with grapes was one of the main obstacles to producing high-quality fruit wines. In the present research, the effect of the split batch fermentation pattern on the metabolites of greengage wines was investigated. This fermentation pattern included whole fruit immersion in the sucrose and coculturing Saccharomyces bayanus Y4 with Torulaspora delbrueckii Y7. These results showed that the contents of total acidity and dominant organic acids were significantly reduced among the batches. Aliphatic compounds were decreased with the batches, while aromatic compounds that contributed to flavor improvement were increased oppositely. The acetate esters, ketones, and terpenes contents were significantly increased in the first batch of coculture. In addition, acidic stress largely affected the kinetics characteristics of greengage wine on a pilot scale. Interestingly, the increment of total acidity was closely associated with the rate of total sugar consumption, which was affected by microbial activities. The acidity content was significantly declined and distinct flavour profiles were formed in split batch and coculture fermentation of greengage wines. It provides a new avenue to enhance the flavor and quality of fruit wines.

Evolution of yeast biodiversity and volatile compounds during spontaneous fermentation of ‘Karasakiz’ grapes from different regions over two consecutive vintages

Spontaneous fermentation may produce complex and unique wines with geographical designations due to the region-specific yeast flora and variations in must characteristics. The current study focused on the yeast diversity and changes in volatile compounds during the spontaneous fermentation of ‘Karasakız’ grapes from three sub-regions of Çanakkale province, Turkey for two vintages (2019 and 2020). This is the first study on the diversity of autochthonous yeasts during wine fermentation of ‘Karasakız’ variety. In the present work, the strains belong to Hanseniaspora uvarum, Starmerella bacillaris, Pichia terricola, Metschnikowia pulcherrima and Zygoascus hellenicus by PCR-RFLP of the ITS region were identified . A total of 272 isolates were identified as S. cerevisiae. Yeast population and diversity changed related to the sub-region and the vintages. However, H. uvarum and S. bacillaris were common denominators of three regions evaluated. H. uvarum was dominant in the early stages of the fermentation, except for Bozcaada 2019 vintage. Bozcaada region also exhibited higher S. cerevisiae strain diversity compared to other regions. 1-Hexanol and 1-octanol gradually decreased during the fermentation of ‘Karasakız’ grapes, while the concentration of isoamyl alcohol, phenylethyl alcohol and ester compounds increased by the fermentation but with some fluctuation.

Proteolytic activity under white wine fermentation by Hanseniaspora vineae yeast strains

Apiculate yeasts from Hanseniaspora genus are predominant on the native flora of grapevines, while Hanseniaspora uvarum is well known for its abundant presence in grapes, it results generally, in detrimental quality effects on wine due to high production of acetic acid. By contrast, Hanseniaspora vineae is better adapted to fermentation, increasing flavor complexity in wines as it has been demonstrated in winemaking practices during the last decade. We obtained a collection of more than 22 different Hanseniaspora vineae strains from which we could detect, by a plating screening method, high and moderate protease activity. In this study, we tested these strains under real winemaking conditions on a Sauvignon blanc white wine must. Results obtained demonstrated that there is an interesting protease active diversity in all H. vineae strains when compared to conventional fermentations conducted by Saccharomyces cerevisiae. Four H. vineae strains showed a decrease in wine protein turbidity, up to three times lower than that observed in S. cerevisiae, which imply a significant decrease in the demand for bentonite before bottling. This attribute of some H. vineaestrains should be very attractive at the commercial level to reduce manipulations and flavor removal in the production of delicate white wines such as Sauvignon blanc.

Effects of different koji on aroma components of Rice Wine

Aroma composition is critical to the quality of rice wine. In order to clarify the effect of different koji on the aroma components of rice wine. The Yuanyang rice was selected as raw material, and three kinds of rice wine koji were added during rice wine fermentation. The aroma components of three wine samples fermented at 31 °C for nine days were qualitatively and quantitatively analyzed by headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that a total of 81 aroma components were detected in the three groups of wine samples, including 30 esters, 18 alcohols, 4 acids and 29 other organic substances. The ester with the most content was ethyl palmitic acid, and the alcohol with the most content was ethanol. Therefore, the amount and type of esters, the ratio and interaction among esters, alcohols and acids in wine play an important role in the sensory quality of rice wine, and the joint action of various aroma components affects the quality of rice wine.

New process of goji fermented wine: effect of goji residue degradation to generate norisoprenoid aroma compounds

In the present study, we compared the color, flavor, and sensory attributes of wines prepared from undegraded (GW1), and physically (GW2) and biologically (GW3) degraded goji residue. Change in wine color showed a similar trend during the aging period; the color gradually became darker, with an increasing red and yellow hue. The wine obtained using the biological method was more clarified, transparent, and lustrous after 30 days of aging. Headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS) detected 7 norisopreniod aroma compounds in GW1 and 9 additional compounds including dihydro-β-ionone, dihydrojasmone, safranal, α-cyclocitral, β-cyclocitral, octanoic acid, 2-octenal, β-damascenon, and geraniol propionate in GW2 and GW3. However, the content of GW3 compounds was higher than GW2 and GW1 compounds. Compared to GW1 and GW2, GW3 compounds showed a more intense floral and fruity aroma with typical wolfberry notes. Sensory evaluation revealed that panelists preferred GW3, followed by GW1 and GW2. Altogether, biodegradation of goji residue produced goji wine with the best color, flavor, and organoleptic qualities. We believe this study will contribute to a better understanding of the brewing and aging process of goji wine and improve its quality.

Proximate Composition of Banana and Pineapple Wine Fermented by Meyerozyma guilliermondii and Pichia guilliermondii

Wine is an alcoholic beverage produced from juices of a variety of fruits by the fermentative action of microorganisms. There is a quest for alternative sources of must for wine fermentation, however, the proximate composition should be known to ascertain how nutritious it is. The study was thus aimed at determining the proximate composition of the wines fermented by Meyerozyma guilliermondii and Pichia guilliermondii. Two isolates identified as Meyerozyma guilliermondii strain 1621 and Pichia guilliermondii strain PAX-PAT 18S were used for the fermentation of the substrates obtained from a mixture of pineapple and banana pulp. The fermentation process was for 28 days, followed by a series of racking, clarification, and aging process which was for 2 months. The fermentation process comprised two setups: one was fermented by Meyerozyma guilliermondii strain 1621 and the other by Pichia guilliermondii strain PAX-PAT 18S. The process was monitored and the proximate analysis of the wines was ascertained. The wine produced by Meyerozyma guilliermondii strain 1621 had a moisture content of 82.56 %, ash content of 1.41 %, fat content of 0.08 %, protein content of 1.43%, and carbohydrate content of 9.77%. The wine produced by Pichia guilliermondii strain PAX-PAT 18S had a moisture content of 79.51%, ash content of 1.19%, fat content of 0.15%, protein content of 0.49%, and carbohydrate content of 10.49%. Although this study is not exhaustive, it shows that wines with good nutritional composition can be successfully produced using Meyerozyma guilliermondii strain 1621 and Pichia guilliermondii strain PAX-PAT 18S.

Development of Green Banana Fruit Wines: Chemical Compositions and In Vitro Antioxidative Activities.

This study aimed to develop functional fruit wines using whole fruit, pulp, and peels from green bananas. The boiled banana homogenates were mixed with cane sugar before wine fermentation. Quality parameters, phenolic compounds, flavor components, and antioxidative properties of the green banana peel wine (GBPW), green banana pulp wine (GBMW), and whole banana wine (GBW) were determined. High-performance liquid chromatography was used to determine the phytochemical compounds in three wines, and the flavor components were further analyzed using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry. The flavor components and in vitro antioxidant activities were, respectively, determined using the relative odor activity value and the orthogonal projections on latent structure discrimination analysis (OPLS-DA). In vitro antioxidative capacities for these wines were evaluated using antioxidant chemical assays and cell culture methods. The total phenolic and total tannin content of the GBPW, GBMW, and GBW showed reducing trends with increasing fermentation days, whereas the total flavonoid content of the wine samples exhibited downward trends. The antioxidant capacities of the three wine samples were higher than those of the raw fruit samples, except for the metal chelation rate (%). Additionally, the main flavor component in the wine samples was 3-methyl-1-butanol. Its percentages in the GBPW, GBMW, and GBW were 72.02%, 54.04%, and 76.49%, respectively. The OPLS-DA results indicated that the three wines presented significantly different antioxidant activities. The cell-culture-based antioxidant analysis showed that these wine samples had protective effects against the oxidative stress of the 3T3-L1 preadipocytes induced by hydrogen peroxide. This study provided a theoretical basis for defining the antioxidant characteristics of banana wines and expanding novel channels for using banana peels to develop nutraceuticals.

Dynamic analysis of microbial communities and flavor properties in Merlot wines produced from inoculation and spontaneous fermentation

The microbiota is of great importance in forming flavor compounds and improving sensory characteristics during wine fermentation. Understanding microbial succession is critical for controlling its contribution to wine flavor with predictable sensory quality. In this study, microbial community composition and characteristic flavor compounds were identified during the inoculation fermentation (IF) and spontaneous fermentation (SF) to provide a basis for exploring the relationship between these microorganisms and volatile components. The results demonstrated that SF had higher fungal community diversity and lower bacterial community diversity than IF. Eleven (11) fungal and 10 bacterial genera (relative abundance > 0.1 %) were considered beneficial microbiota. Saccharomyces, Hanseniaspora, and Alternaria were the leading fungal genera in SF. Massilia, Nesterenkonia, and Halomonas were the predominant bacteria in IF, while Tatumella and Ochrobactrum were mainly from SF. In addition, the microbial community composition was reshaped via correlational analysis between microbiota succession and physicochemical properties, mainly attributed to the changes in environmental factors during fermentation. The SF wines had more aromatic higher alcohols, acetate esters, and terpenes. Also, the sensory evaluation showed that the SF wines were characterized by more fruity, floral, intense, and typical aromas. The associations between the microbial community and the volatile components indicated that the dominant species largely determined the characteristic flavor compounds during fermentation.

Multi-Functional Separation Mode-Ion Chromatography Using L-Pyroglutamic Acid Eluent for Simultaneous Determination of Sugars, Organic Acids, and Ethanol during Multiple Parallel Fermentation of Rice Wine

An effective evaluation method for understanding fermentation is required to support the implementation of newly developed yeast strains in brewing. Our group developed a multi-functional separation mode-ion chromatography (MFS-IC) with conductivity and refractive index detectors to separate key species (glucose, ethanol, and organic acids: pyruvate, citrate, L-malate, and succinate) with ethyl α-D-glucoside and glycerol to understand the fermentation behavior in brewing. Optimal chromatographic resolutions for determining eight different key species in rice wine by the MFS-IC were obtained in 45 min on low-molecular size-exclusion chromatographic separation columns modified with a strong cation-exchanger as the stationary phase with an eluent of L-pyroglutamic acid. Understanding the behavior of analytes in rice wine samples during rice wine fermentation enables the monitoring of the progress of saccharification, glycolysis, ethanol fermentation, and the tricarboxylic acid (TCA) cycle. These results are expected to contribute to understanding fermentation characteristics and implementing newly developed yeast strains in the fermentation field.

Study of the Effect of Antibiotics in Drinking Water on the Content of Antioxidant Compounds in Red Wines

The presence of antibiotic residues in drinking water may be a source of contamination, which could affect the diffusion of polyphenols into the wine must during the traditional fermentation process. Antibiotic residues such as ivermectin, hydroxychloroquine, ciprofloxacin, and azithromycin on the diffusion of polyphenols and anthocyanins during wine fermentation were studied. Different samples were taken at different periods (0, 48, 96, and 168 h) to analyse the total polyphenols, anthocyanin content, and antioxidant capacity, which were correlated with Peleg's equation to establish the diffusion kinetics of these compounds. The results indicated that the presence of antibiotics reduced between 40 and 50% the diffusion of the total polyphenols and monomeric anthocyanins in red wine. The use of ivermectin showed the highest kinetic parameter k1 compared with the use of other antibiotics. This suggested that the chemical structure and molecular weight of the antibiotics could play an important role in inhibiting the metabolism of yeasts affecting the ethanol and CO2 production. Consequently, cell membranes would be impermeable and would not allow the release of polyphenols and anthocyanins. Therefore, it is necessary to establish strategies that allow future water quality control in wine production companies.

Analysis of the formation mechanism of volatile and non-volatile flavor substances in corn wine fermentation based on high-throughput sequencing and metabolomics

The purpose of this study was to reveal the relationship between core microorganisms and flavor substances in the fermentation process of corn wine. Microbial diversity, volatile and non-volatile flavor substances were detected by high-throughput sequencing (HTS), headspace solid phase micro-extraction gas chromatography-mass spectrometry (HS-SPME/GC–MS) and gas chromatography time of flight mass spectrometry (GC-TOF-MS). High performance liquid chromatography (HPLC) was used to detect organic acids in corn wine fermentation, and its physiochemical properties were tracked. The results showed that physiochemical factors changed obviously with fermentation time. Bacillus, Prevotella_9, Acinetobacter and Gluconobacter were the predominant bacterial. Rhizopus and Saccharomyces were the dominant fungi. Acetic acid and succinic acid were important organic acids in corn wine. According to variable importance of projection (VIP) > 1 and P < 0.05, 24 volatile flavor substances with significant difference were screened out from 52 volatile flavor substances. Similarly, 25 non-volatile flavor substances with significant differences were screened out from the 97 reliable metabolites identified by 223 chromatographic peaks. Eight key metabolic pathways were enriched from 25 non-volatile flavor substances according to path influence values > 0.1 and P < 0.05. Based on Two-way Orthogonal Partial Least Squares (O2PLS) model and Pearson correlation coefficient, Saccharomyces, Rhizopus, uncultured_bacterium, Aneurinibacillus, Wickerhamomyces and Gluconobacter may be the potential volatile flavor-contributing microorganism genus in corn wine. The Pearson correlation coefficient showed that Saccharomyces was significantly positively correlated with malic acid, oxalic acid, valine and isoleucine, and Rhizopus was positively correlated with glucose-1-phosphate and alanine. These findings enhanced our understanding of the formation mechanism of flavor substances in corn wine and provided the theoretical basis for stabilizing flavor quality of corn wine.

Advanced Monitoring and Control of Redox Potential in Wine Fermentation across Scales

Combined with real-time monitoring of density and temperature, the control of the redox potential provides a new approach to influencing cell metabolism during growth, cell viability and non-growing yeast activity in wine fermentations. Prior research indicates that the problem of sluggish and incomplete fermentation can be alleviated by maintaining a constant redox potential during the ethanol fermentation. A secondary trait of hydrogen sulfide formation from elemental sulfur also seems to be associated with the development of low redox potentials during fermentation and this might be prevented by the deliberate control of redox potentials in a certain range. While the control of the redox potential during wine fermentations has been demonstrated previously at the research scale (100 L), the ability to control it in larger volumes typically seen in commercial conditions remained unanswered. Wine fermentations from the same load of Cabernet Sauvignon grapes from the 2021 harvest were conducted at three volumes: 100 L and 1500 L in a research winery and 10,000 L in a commercial winery. Using only pulses of air delivery, the redox potential was successfully controlled to −40 mV referenced to a silver/silver chloride electrode throughout the fermentations, at all scales. This appears to be the first published result of a controlled fermentation trial that includes the commercial scale and demonstrates the scalability of control of redox potential in wine fermentations.

Molecular and Physiological Diversity of Indigenous Yeasts Isolated from Spontaneously Fermented Wine Wort from Ilfov County, Romania.

(1) Background: Wine yeast research offers the possibility of isolating new strains with distinct metabolic properties due to the geographical location of the vineyard and the processes used in winemaking. Our study deals with the isolation and identification of six yeasts from spontaneously fermented wine wort from Romania and their characterization as new potential starter culture for traditional beverages, for food industry or biomedicine. (2) Materials and methods: The isolates were identified using conventional taxonomy tests, phenotypic phylogeny analysis (Biolog YT), MALDI-TOF mass spectrometry, PCR-RFLP, and sequencing of the ITS1-5,8S-ITS2 rDNA region. The capacity of the yeasts to grow under thermal, ionic, and osmotic stress was determined. The safe status was confirmed by testing virulence and pathogenicity factors. Assays were performed in order to evaluate the growth inhibition of Candida strains and determine the antimicrobial mechanism of action. (3) Results and discussions: The yeast isolates were identified as belonging to the Metschinikowia, Hanseniaspora, Torulaspora, Pichia, and Saccharomyces genera. All the isolates were able to develop under the tested stress conditions and were confirmed as safe. With the exception of S. cerevisiae CMGB-MS1-1, all the isolates showed good antimicrobial activity based on competition for iron ions or production of killer toxins. (4) Conclusions: The results revealed the resistance of our yeasts to environmental conditions related to industrial and biomedical applications and their high potential as starter cultures and biocontrol agents, respectively.

Synthesis of Aroma Compounds as a Function of Different Nitrogen Sources in Fermentations Using Non-Saccharomyces Wine Yeasts.

Non-Saccharomyces yeasts are prevalent at the onset of grape must fermentations and can have a significant influence on the final wine product. In contrast to Saccharomyces cerevisiae, the biosynthetic pathways leading to aroma compound formation in these non-conventional yeasts, in particular those that are derived from amino acid metabolism, remains largely unexplored. Within a synthetic must environment, we investigated the amino acid utilization of four species (Hanseniaspora uvarum, Hanseniaspora osmophila, Zygosaccharomyces rouxii, Starmerella bacillaris) and S. cerevisiae. We report on the differential uptake preferences for amino acids with H. uvarum displaying the most rapid uptake of most amino acids. To investigate the fate of amino acids and their direct contribution to aroma synthesis in H. uvarum, H. osmophila and Z. rouxii, musts were supplemented with single amino acids. Aroma profiling undertaken after three days showed the synthesis of specific aroma compounds by the respective yeast was dependent on the specific amino acid supplementation. H. osmophila showed similarities to S. cerevisiae in both amino acid uptake and the synthesis of aroma compounds depending on the nitrogen sources. This study shows how the uptake of specific amino acids contributes to the synthesis of aroma compounds in wine fermentations using different non-Saccharomyces yeasts.

Investigation by High-Throughput Sequencing Methods of Microbiota Dynamics in Spontaneous Fermentation of Abruzzo (South Italy) Wines

Spontaneous wine fermentation is a meaningful topic that cannot be disregarded among winemakers and consumers due to the peculiarity of the organoleptic profile that it confers to the wine. Nevertheless, in this process the activity of indigenous microorganisms might be a threat. We studied the evolution of the spontaneous fermentation process in a traditional Italian winery in order to understand the origin of spoilage microorganisms, and to characterize the peculiarity of the microbiota associated with spontaneous fermentation. Six Trebbiano and Montepulciano wine production chains were monitored by plate counts made by OIV methods and by Illumina MiSeq technique. Despite some compositional deficiencies, all grape musts were characterized by a highly concentrated microbial population. Non-Saccharomyces yeasts revealed an unexpected tolerance to ethanol, which has contributed to the evolution of alcoholic fermentation. Lactic bacteria were detectable from the very first steps of the winemaking process, with a prevalence of Leuconostoc spp. which is nowadays, rarely isolated in wine. The combination between culture-dependent and high-throughput sequencing (HTS) approaches allowed to estimate microbial diversity and growth dynamics in wine fermentations of different grape varieties and under different treatments; these results could be used by winemakers as a starting point to drive a more mindful, accurate and, controlled fermentation process and to set up the most suitable environmental conditions to enhance wine singularities.

Detection of bacterial spoilage during wine alcoholic fermentation using ATR-MIR and MCR-ALS

A new methodology is proposed to describe the evolution of the main chemical compounds of grape must during wine alcoholic fermentation using Attenuated Total Reflectance Mid Infrared (ATR-MIR) spectra in combination with Multivariate Curve Resolution Alternating Least-Squares (MCR-ALS). In addition, we have developed a process control strategy to detect differences between fermentations running under Normal Operation Conditions (NOC) and fermentations intentionally spoiled with lactic acid bacteria at the beginning of alcoholic fermentation (MLF) to promote deviations from NOC. MCR-ALS models on these data showed a good data fit (R 2 = 99.95% and lack of fit = 2.31%). It was possible to resolve the spectral profiles of relevant molecules involved in the alcoholic fermentation process, including the one related to bacterial spoilage (lactic acid). MSPC charts were built based on the concentration profiles obtained from the MCR-ALS models and using T 2 and Q statistics. Spoiled wines showed off-limit values for T 2 after 96 hours, making it possible to detect lactic acid bacteria spoilage in early stages of alcoholic fermentation. Thus, the use of ATR-MIR spectra and MCR-ALS analysis shows a great potential for a rapid control of the state of the alcoholic fermentation process, making it possible to early detect the appearance of undesired molecules during the process, which allows the winemaker to apply corrective measures and obtain a good final product. • ATR-MIR and MCR-ALS allow resolving main compounds involved in wine fermentation. • T 2 and Q MSPC charts are built using MCR-ALS concentration profiles. • The concept of ‘Inverse’ MSPC charts' is introduced. • Early detection of undesired molecules related to bacterial spoilage is achieved.

Malolactic Fermentation: New Approaches to Old Problems.

Malolactic fermentation (MLF) is the decarboxylation of L-malic acid to L-lactic acid by lactic acid bacteria (LAB). For the majority of wine production, secondary fermentation is crucial. MLF significantly impacts the quality of most red and some white wine. The outcomes of the spontaneously initiated and finished MLF are frequently unpredictable and can even cause the wine to deteriorate. As a result, individuals typically favour inoculating superior starter cultures when performing MLF. The MLF method for wine has, however, faced new difficulties because of the altered wine fermentation substrate environment brought on by global climate change, the growing demands of winemakers for production efficiency, and the rising demand for high-quality wine. To serve as a reference for the study of wine production and MLF in the current situation, this review primarily updates and summarises the research findings on increasing the effectiveness and dependability of MLF in recent years.

Impact of rare yeasts in Saccharomyces cerevisiae wine fermentation performance: Population prevalence and growth phenotype of Cyberlindnera fabianii, Kazachstania unispora, and Naganishia globosa

Saccharomyces cerevisiae is a highly fermentative species able to complete the wine fermentation. However, the interaction with other non-Saccharomyces yeasts can determine the fermentation performance of S. cerevisiae. We have characterised three rare non-Saccharomyces yeasts (Cyberlindnera fabianii, Kazachstania unispora and Naganishia globosa), studying their impact on S. cerevisiae fitness and wine fermentation performance. Using a wide meta-taxonomic dataset of wine samples, analysed through ITS amplicon sequencing, we show that about a 65.07% of wine samples contains Naganishia spp., a 27.21% contains Kazachstania spp., and only a 4.41% contains Cyberlindnera spp; in all cases with average relative abundances lower than 1% of total fungal populations. Although the studied N. globosa strain showed a limited growth capacity in wine, both K. unispora and C. fabianii showed a similar growth phenotype to that of S. cerevisiae in different fermentation conditions, highlighting the outstanding growth rate values of K. unispora. In mixed fermentations with S. cerevisiae, the three yeast species affected co-culture growth parameters and wine chemical profile (volatile compounds, polysaccharides and proteins). K. unispora DN201 strain presents an outstanding capacity to compete with S. cerevisiae strains during the first stage of wine fermentation, causing stuck fermentations in both synthetic and natural grape musts.

Effect of Hanseniaspora uvarum-Saccharomyces cerevisiae Mixed Fermentation on Aroma Characteristics of Rosa roxburghii Tratt, Blueberry, and Plum Wines.

Hanseniaspora uvarum, a non-Saccharomyces cerevisiae species, has a crucial effect on the aroma characteristics of fruit wines, thus, attracting significant research interest in recent years. In this study, H. uvarum-Saccharomyces cerevisiae mixed fermentation was used to ferment Rosa roxburghii Tratt, blueberry fruit wine, and plum fruit wines using either a co-inoculated or a sequentially inoculated approach. The three fruit wines' volatile aroma characteristics were analyzed by headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that the mixed inoculation of H. uvarum and S. cerevisiae reduced the alcoholic content of Kongxinli fruit wine. Moreover, H. uvarum-S. cerevisiae fermented Rosa roxburghii Tratt, blueberry, and plum fruit wines and further enriched their flavor compounds. The overall flavor characteristics of sequentially inoculated fruit wines differed significantly from those fermented with S. cerevisiae alone, although several similarities were also observed. Sequential inoculation of H. uvarum and S. cerevisiae positively affected the mellowness of the wine and achieved a better harmony of the overall wine flavors. Therefore, H. uvarum-Saccharomyces cerevisiae mixed fermentation can improve the complexity of the wines' aromatic composition and empower them with a unique identity. In particular, H. uvarum-Saccharomyces cerevisiae blueberry wine produced by mixed fermentation had the widest variety and content of aroma compounds among the fermented wines. Therefore, H. uvarum-Saccharomyces cerevisiae mixed-fermentation inoculation in the three fermented fruit wines significantly increased the aroma compound variety and content, thus, enriching their aroma richness and complexity. This study is the first comparative evaluation of the aroma characteristics of different fruit wines fermented with a mixed inoculation of H. uvarum and S. cerevisiae and provides a preliminary guide for these fruit wines produced with non-Saccharomyces yeast.