Wine Fermentation Research Articles

Modelling of Catechin Extraction from Red Grape Solids under Conditions That Simulate Red Wine Fermentation

Digital control systems are well established in many industries and could find application in the wine sector. Of critical importance to red wine quality, the efficient and targeted extraction of polyphenols from red grape solids during alcoholic fermentation could be a focus for automation. Smart technologies such as model predictive control (MPC) or fuzzy logic appear ideal for application in a complex process such as wine polyphenol extraction, but require mathematical models that accurately describe the system. The aim of this study was to derive and validate a model describing the extraction of catechin (a representative polyphenol) from red grape solids under simulated fermentation conditions. The impact of ethanol, fermentable sugar, and temperature on extraction rate was determined, with factor conditions chosen to emulate those present in industry practice. A first-order approach was used to generate an extraction model based on mass conservation that incorporated temperature and sugar dependency. Coefficients of determination (R2) for all test scenarios exceeded 0.94, indicating a good fit to the experimental data. Sensitivity analysis for the extraction rate and internal cross-validation showed the model to be robust, with a small standard error in cross-validation (SECV) of 0.11 and a high residual predictive deviation (RPD) of 17.68. The model that was developed is well suited to digital technologies where low computational overheads are desirable, and industrial application scenarios are presented for future implementation of the work.

Effects of Four Critical Gene Deletions in Saccharomyces cerevisiae on Fusel Alcohols during Red Wine Fermentation

Excessive fusel alcohols in red wine will bring an uncomfortable bitterness and generate an intoxicating effect, which affects the quality and attractivity of the red wine. In order to achieve better regulation of fusel alcohols in red wine, strains with LEU1 and PDC5 deletions were constructed, and seven engineered yeast strains based on THI3 and BAT2 deletions were applied to red wine fermentation to dissect the effects of four critical genes on fusel alcohols during wine fermentation. The fermentation results of these recombinant strains showed that the deletion of THI3 increased the contents of n-propanol, isobutanol, and isoamyl alcohol by 48.46%, 42.01%, and 7.84%, respectively; the deletion of BAT2 decreased isoamyl alcohol and isobutanol by 32.81% and 44.91%; the deletion of PDC5 and LEU1 decreased isoamyl alcohol by 40.21% and 68.28%, while increased isobutanol by 24.31% and 142%, respectively; the deletion of THI3 exerted a negative influence on the reduction of isoamyl alcohol caused by BAT2 or PDC5 deletion; the deletion of THI3 and PDC5 had a synergistic effect on the increase of isobutanol, while BAT2 and PDC5 deletion presented no additive property to the decrease of isoamyl alcohol. Hence, it is concluded that either BAT2, PDC5, or LEU1 deletion can effectively decrease fusel alcohols, especially isoamyl alcohol, which provides an important reference for the control of fusel alcohols in red wine.

PEP4-Allele Modification Provides an Industrial Brewing Yeast with Malate Stress Tolerance

Acid stress is a challenging condition that yeast cells must overcome during fermentation. Enhancing the inherent tolerance of industrial Saccharomyces cerevisiae to organic acid stresses is crucial for increasing fermentation efficiency and reducing economic costs. In a previous study, we constructed a Saccharomyces cerevisiae strain SWY85S with improved tolerance to citric acid stress by modifying the second PEP4-allele. Malic acid is a dominant organic acid in grapefruit, which forms the acidic constituents of wine fermentation mash and finished products. We investigated the malic acid stress tolerance of the strain SWY85S in comparison with that of a strain with one PEP4-allele disrupted and the wild-type strain in this study. Our results revealed that the strain SWY85S demonstrated greater tolerance of malic acid stress, regardless of whether it was cultured with adequate nutrient supplies or under amino acid starvation. Moreover, the strain SWY85S performed remarkably in converting glucose to ethanol during fermentation under malic acid stress. This study provides insights into the role of a vacuolar PEP4-allele coding product in response to environmental stress and the physiological mechanism of yeast to withstand organic acid stress.

Selection of Saccharomyces cerevisiae Isolates from Helan Mountain in China for Wine Production

S. cerevisiae strains were isolated and identified from vineyards and the spontaneous fermentation must at the eastern foot of Helan Mountain in China, and their oenological properties and fermentation abilities were analyzed. From the total of 199 S. cerevisiae strains isolated and identified, 14 isolates (F4-13, F5-7, F5-9, F5-12, F5-18, F5-19, F5-21, F6-8, F6-23, F9-23, SXY-4, HT-10, ZXY-17, MXY-19) exhibited excellent tolerance to sugar, SO2, and ethanol. Among the isolates, the strain F4-13 exhibited the better oenological properties, with low H2S production (+), suitable flocculation ability (58.74%), and reducing-L-malic acid ability (49.07%), and generated high contents of polyphenol, anthocyanin, tannin, terpenes, and higher alcohols, which contributed to the improvement of the red fruity and floral traits of the wines. The obtained results provide a strategy for the selection of indigenous S. cerevisiae for wine fermentation to produce high-quality wine with regional characteristics.

Early transcriptional response of Saccharomyces cerevisiae in mixed culture with Torulaspora delbrueckii in cherry wine

Mixed culture by Saccharomyces cerevisiae and Torulaspora delbrueckii has been proposed for the production of wine with improved aroma, but the yeast-yeast interactive mechanism still needs in-depth elucidation. This study compared the transcriptome responses of S. cerevisiae in single and mixed fermentations with T. delbrueckii, in the initial stages of cherry wine fermentation, in order to disclose the possible relationship between aroma synthesis and gene expression. Transcriptome profiling showed a total of 446 and 186 differentially expressed genes were detected in S. cerevisiae and T. delbrueckii, respectively, and several metabolic pathways such as glucose, lipid and amino acid metabolisms were observed with variations. For aroma, a total of 35 volatile compounds were identified by HS-GC-IMS, and mixed fermentation prominently enhanced the syntheses of most esters including propyl acetate, 2-methylpropyl acetate, isoamyl acetate and 2-methylbutyl acetate. By integrating the transcriptomic and volatile results, we propose that ILV5, BATs, PDCs, ADHs, ALDs, ACS1, ACC1 and ARO10 genes are possibly the decisive genes in S. cerevisiae, which showed significant variations following S. cerevisiae's adaptive responses in mixed culture and associated with the formation of certain aldehydes, alcohols and esters in cherry wine.

Formation of vinylphenolic pyranoanthocyanins by selected indigenous yeasts displaying high hydroxycinnamate decarboxylase activity during mulberry wine fermentation and aging

The color of mulberry wine is difficult to maintain since the main chromogenic substances, anthocyanins, are severely degraded during fermentation and aging. This study selected Saccharomyces cerevisiae I34 and Wickerhamomyces anomalus D6, both displaying high hydroxycinnamate decarboxylase (HCDC) activity (78.49% and 78.71%), to enhance the formation of stable vinylphenolic pyranoanthocyanins (VPAs) pigments during mulberry wine fermentation. The HCDC activity of 84 different strains from eight regions in China was primarily screened via the deep well plate micro fermentation method, after which the tolerance and brewing characteristics were evaluated via simulated mulberry juice. The two selected strains and a commercial Saccharomyces cerevisiae were then inoculated individually or sequentially into the fresh mulberry juice, while the anthocyanin precursors and VPAs were identified and quantified via UHPLC-ESI/MS. The results showed that the HCDC-active strains facilitated the synthesis of stable pigments, cyanidin-3-O-glucoside-4-vinylcatechol (VPC3G), and cyanidin-3-O-rutinoside-4-vinylcatechol (VPC3R), highlighting its potential for enhancing color stability.

Continuous fed-batch strategy decreases acetic acid production and increases volatile ester formation in wines under high-gravity fermentation

High sugar fermentation elevates acetic acid levels in wines, which can be avoided by applying the continuous fed-batch strategy. In this study, yeast gene expressions and wine volatile compounds were evaluated by quantitative real-time PCR (RT-qPCR) and gas chromatograph mass spectrometry (GC-MS) in high-gravity (HG, 320 g/L sugars) fermentations with different batch strategies. The acetic acid concentration in continuous fed-batch fermentation wine was reduced by 51.69 %, compared with that in whole-batch fermentation wine. The acetyl-CoA synthase gene (ACS2) expression was up-regulated, whereas the glycerol-3-phosphate dehydrogenase gene (GPD1) expression was down-regulated on day 3 and day 7 during the continuous fed-batch fermentation. The volatile ester concentration in continuous fed-batch fermentation wine was 36.74 % higher than that in whole-batch fermentation wine. Overall, the continuous fed-batch strategy can modulate the expression of yeast genes involved in acetic acid metabolism and can increase volatile esters in wine under high sugar fermentation. Our findings provide a reference for the application of a continuous fed-batch strategy in high-sugar fermentation so as to improve the quality of the wine.

Evaluation of Physicochemical and Microbial Properties of Extracts from Wine Lees Waste of Matelica's Verdicchio and Their Applications in Novel Cosmetic Products.

Wine lees are sediments deposited on the walls and bottom of barrels resulting from wine fermentation and mainly consist of yeasts. Saccharomyces cerevisiae extracts, rich in beneficial components for the skin, have already been used in cosmesis, while wine lees have not been well exploited by the cosmetics industry yet. The aim of this work was the full characterization of the wine lees from Verdicchio's wine, with the aim to exploit it as a beneficial ingredient in new cosmetic products. After mapping the microbial composition of the sample waste, the parameters for the sonication extraction process were optimized and the physicochemical properties of the extract were analyzed. The efficiency of the aqueous extraction-and in particular the yeast cell lysis necessary for the release of proteins from the cell-was assessed by evaluating cell shape and size, and protein release, under scanning electron microscopy (SEM), dynamic light scattering (DLS) and Bradford's protein assays. Thus, the total phenol content and antioxidant capacity of the supernatant recovered from native and sonicated lees were determined by Folin-Ciocalteu's and spectrophotometric assays, respectively. To quantify the heavy metals and highlight the presence of microelements beneficial for the skin, inductively coupled plasma-mass spectrometry (ICP-MS) was applied. In vitro metabolic activity and cytotoxicity were tested on both HaCat keratinocytes and human gingival fibroblasts, showing that wine lees are safe for skin's cells. The results show that sonicated lees appear to be more interesting than native ones as a consequence of the release of the active ingredients from the cells. Due to the high antioxidant capacity, content of beneficial elements for skin and an appropriate microbiologic profile, wine lees were included in five new solid cosmetic products and tested for challenge test, compatibility with human skin, sensory analysis, trans epidermal water loss (TEWL) and sebometry.

Characterization of Zygosaccharomyces lentus Yeast in Hungarian Botrytized Wines.

Tokaj botrytized sweet wines are traditionally aged for several years in wood barrels or bottles. As they have significant residual sugar content, they are exposed to microbial contamination during ageing. Osmotolerant wine-spoilage yeasts are most commonly found in the Tokaj wine-growing region in the species Starmerella spp. and Zygosaccharomyces spp. For the first time, Z. lentus yeasts were isolated from post-fermented botrytized wines. Our physiological studies confirmed that these yeast strains are osmotolerant, with high sulphur tolerance and 8% v/v alcohol tolerance, and that they grow well at cellar temperature in acidic conditions. Low β-glucosidase and sulphite reductase activities were observed, whereas protease, cellulase, and α-arabinofuranosidase extracellular enzyme activities were not detected. Molecular biology analyses carried out by RFLP analysis of mtDNA revealed no remarkable differences between strains, while microsatellite-primed-PCR fingerprinting of the (GTG)5 microsatellite and examination of chromosomal pattern revealed considerable diversity. The fermentative vigour of the tested Z. lentus strains was found to be significantly lower compared to the control Saccharomyces cerevisiae (Lalvin EC1118). It can be concluded that Z. lentus is a potential spoilage yeast in oenology which may be responsible for the initiation of secondary fermentation of wines during ageing.

Beyond S. cerevisiae for winemaking: Fermentation-related trait diversity in the genus Saccharomyces

Saccharomyces cerevisiae is the yeast of choice for most inoculated wine fermentations worldwide. However, many other yeast species and genera display phenotypes of interest that may help address the environmental and commercial challenges the wine industry has been facing in recent years. This work aimed to provide, for the first time, a systematic phenotyping of all Saccharomyces species under winemaking conditions. For this purpose, we characterized the fermentative and metabolic properties of 92 Saccharomyces strains in synthetic grape must at two different temperatures. The fermentative potential of alternative yeasts was higher than expected, as nearly all strains were able to complete fermentation, in some cases more efficiently than commercial S. cerevisiae strains. Various species showed interesting metabolic traits, such as high glycerol, succinate and odour-active compound production, or low acetic acid production, compared to S. cerevisiae. Altogether, these results reveal that non-cerevisiae Saccharomyces yeasts are especially interesting for wine fermentation, as they may offer advantages over both S. cerevisiae and non-Saccharomyces strains. This study highlights the potential of alternative Saccharomyces species for winemaking, paving the way for further research and, potentially, for their industrial exploitation.

Bioconvertibility of fermentative vert wine: a comparative study of blue- green algae, pineapple, and longan fruits

This research delves into the innovative fermentation of wines using blue-green algae (spirulina), pineapple, and longan fruit. Traditional wine consumption, often synonymous with alcohol content, has seen a shift in value and health appeal with the infusion of spirulina. The fermentation process was monitored using both single and mixed cultures of Saccharomyces cerevisiae until it achieved 12% alcohol content. Sensory evaluations by fruit wine consumers revealed gender-based preferences in the acceptability of tangerine wine formulations. Specifically, females showed a higher liking for 5 out of 9 wine formulas, with sugar and acidity playing pivotal roles in flavours preference. Three distinct algae wine recipes were fermented at room temperature, with chemical analyses post-fermentation indicating standard pH levels for wine (3.0 - 4.0). Among them, the seaweed-pineapple blend was the standout, with a pH of 3.55 and a 72.96% approval rate among taste testers. The economic analysis highlighted the pineapple-seaweed variant's high production cost, though pure spirulina wine boasted the most significant return on investment. In conclusion, pineapple-infused spirulina wine emerges as a frontrunner in terms of taste, standard adherence, and economic viability, presenting a solution to the regional fruit surplus.

Characterization of the Pure Black Tea Wine Fermentation Process by Electronic Nose and Tongue-Based Techniques with Nutritional Characteristics.

Wine is an alcoholic beverage, consisting of several compounds in various ranges of concentrations. Wine quality is usually assessed by a sensory panel of trained personnel. Electronic tongues (e-tongues) and electronic noses (e-noses) have been established in recent years to assess the quality of beverages and foods. Response surface and electronic analysis tools were used to examine the quality of black tea wine. The results indicated the optimum initial sugar level (25 °Brix), yeast addition (0.5%), and fermentation temperature (25 °C) for Golden Peony black tea wine. The black tea wine produced under these conditions with 14.0% vol alcohol has as an orange-red color, full wine and tea flavor, and mild and mellow taste. The sourness of the wine was most affected by fermentation factors-yeast addition, fermentation temperature, and initial sugar level. Alcohols, aldehydes, ketones, and alkanes contributed to most of the volatile components under the influence of yeast addition and fermentation temperature. In contrast, nitrogen oxides, aromatics, and organic sulfides contributed under the influence of the initial sugar level. This study provided a facilitated strategy for obtaining the optimum black tea wine fermentation process through electronic nose and tongue-based techniques. The analysis of wines requires new technologies able to detect various different compounds simultaneously, providing worldwide information about the sample instead of information about specific compounds.

Microsatellite typing of Lachancea thermotolerans for wine fermentation monitoring

Climate change is causing a lack of acidity during winemaking and oenologists use several solutions to cope with such a problem. Lachancea thermotolerans, which has the potential to tolerate the harsh physicochemical conditions of wine, has emerged as a promising alternative for pH management during winemaking and, currently, it is the most valuable yeast used for acidity control in wine. In this work a manageable method for L. thermotolerans genotyping based on a multiplexed microsatellite amplification in 6 different loci was developed. The proposed method was used to distinguish between 103 collection strains obtained from different geographical and isolation sources, and then challenged against a 429 L. thermotolerans isolates from several wineries and harvests. The procedure was also tested for fermentation monitoring and strain implantation. This approach was conceived to simplify the methodology available for L. thermotolerans genotyping, making it easy for applying in wine-related laboratories. This method can be applied to distinguish between L. thermotolerans strains in selection programs and to follow implantation of inoculated strains during winemaking with optimal results.

Investigation of wine fermentation of three-leaf cayratia (Cayratia trifolia L.) using Saccharomyces cerevisiae 2.1

Background: Cayratia trifolia has been extensively studied for its bioactive components and medicinal properties. This study was carried out to evaluate the fermentation ability of Saccharomyces cerevisiae 2.1 yeast to determine suitable fermentation conditions. Methods: The initial sugar content for three-leaf cayratia fermentation and fermentation efficiency were calculated. The temperature for three-leaf cayratia fermentation, incubation time, and preliminary 1 liter of three-leaf cayratia wine fermentation were determined. All treatments showed that the total sugar content decreased after 9 days of fermentation compared to the initial level. Temperature during fermentation has a direct effect on yeast activity. Temperature increases the growth of yeast and speed of enzyme activity. The fermentation time changes depending on temperature, initial soluble solid contents, and yeast strains, leading to changes in the ethanol content after the end of fermentation. Results: The results showed that the S. cerevisiae 2.1 strain was able to ferment at room temperature with an initial pH of 4.5, 24 °Brix, and a yeast density of 107 cells/mL. The appropriate fermentation conditions determined for S. cerevisiae 2.1 yeast were 24 °Brix and incubation at room temperature (28-33°C) with a fermentation time of 11 days. Concusion: In 1 liter scale fermentation, three-leaf cayratia wine had 9.46% (v/v) and the fermentation efficiency was 90.34%. The wine produced had a unique color, flavor, and aroma that met the sensory evaluation of the Vietnamese standard TCVN-3217:79.

The Microbial Terroir of the Nemea Zone Agiorgitiko cv.: A First Metataxonomic Approach

Vitis vinifera L. cv. Agiorgitiko is one of the most popular indigenous wine grape varieties in Greece, cultivated almost exclusively in the Nemea Protected Designation of Origin (PDO) zone. Here, the microbiota of soil, grapes, and wine, during controlled (CF) and spontaneous (SF) fermentations of Agiorgitko cv. from three vineyards in the PDO Nemea zone were explored, using both classical microbiological analysis and metataxonomics to get evidence about the microbial terroir of the PDO Nemea zone. The classical microbiological analysis revealed higher total mesophilic counts in soil, while in both grapes and wine samples, yeasts prevailed. Lactic acid bacteria and acetic acid bacteria counts were lower in grapes compared to wine and soil. Metataxonomic analysis revealed that, regarding yeasts/fungi, genera Fusarium, Sarea, and Alternaria dominated in soil; Aureobasidium, Cladosporium, and Penicillium in grapes; Saccharomyces in wine during CF; and Hanseniaspora and Saccharomyces in wine during SF. Regarding bacteria, genera Skermanella, Acidobacterium, and Ohtaekwangia dominated in soil, Sphingomonas, Micrococcus, and Rubrobacter in grapes, while Tatumella, Alcanivorax, and Komagateibacter in wine during both CF and SF. Finally, the factors that significantly influence the microbiota of soil, grapes, and wine samples were assessed, and potential microbial biomarkers were identified for the first time in a Greek grape variety.

Optimization of Mopan Persimmon Wine Fermentation with Pectinase and Analysis of Its Mechanism of Action

Due to the high sugar content of Mopan persimmon, which has an annual output of more than 0.5 million tons in China, it can be processed to make fruit wine. In this study, a strain of yeast screened from different persimmon samples was used for persimmon wine fermentation. The optimal conditions of persimmon wine fermentation were determined through single-factor experiments as follows: Yeast addition of 0.08 g/kg; a fermentation temperature of 28 °C; sucrose addition of 18%; and pectinase addition of 0.01%. Under these conditions, the alcohol content of persimmon wine reached 12.9%. The addition of pectinase during persimmon wine fermentation was found to decompose pectin at high speed, reduce the viscosity of the fermentation liquid, increase the dissolved oxygen content in the fermentation liquid, promote the growth and reproduction of yeast, and effectively convert the sugars into alcohol. After fermentation, alcohol, residual sugars, and total phenolic content with or without pectinase treatment were 12.9 and 4.4%, 2.2 and 13.4 g/L, and 738.7 and 302 µg/mL, respectively. Scanning electron microscopy (SEM) results showed that compared with the mash without pectinase treatment, the mash with pectinase had a larger network structure and more pores and yeasts.

Monitoring the viable grapevine microbiome to enhance the quality of wild wines

Grapevines that are used for winemaking host a diverse range of microorganisms that make up their microbiome. The microbes that inhabit the grapevine have been used by winemakers to produce wine for centuries, although modern wine producers often rely on inoculated microorganisms such as Saccharomyces cerevisiae. In the Australian wine industry, there is a movement towards returning to the utilisation of the microbiome for wine fermentation. With the recent increase in the understanding of the role of the grapevine microbiome in grapevine health, fermentation and subsequent wine sensory traits, the microbial world offers a new level of complexity that can be harnessed for winemaking. In order to develop and maintain a desired vineyard micro-biodiversity, extensive microbial monitoring is required. Here we discuss the utilisation of a viability selection dye in order to distinguish between microorganisms that are live and associated with the host, and relic signals generated from non-living sources.

Experimental evolution forcing Oenococcus oeni acid tolerance highlights critical role of the citrate locus

Oenococcus oeni is the main lactic acid bacterium associated with malolactic fermentation (MLF) of wines. MLF plays an important role in determining the final quality of wines. Nevertheless, due to the stressful conditions inherent to wine and especially acidity, MLF may be delayed. This study aimed to explore by adaptive evolution improvements in the acid tolerance of starters but also to gain a better understanding of the mechanisms involved in adaptation toward acidity. Four independent populations of the O. oeni ATCC BAA-1163 strain were propagated (approximately 560 generations) in a temporally varying environment, consisting in a gradual pH decrease from pH 5.3 to pH 2.9. Whole genome sequence comparison of these populations revealed that more than 45% of the substituted mutations occurred in only five loci for the evolved populations. One of these five fixed mutations affects mae, the first gene of the citrate operon. When grown in an acidic medium supplemented with citrate, a significantly higher bacterial biomass was produced with the evolved populations compared to the parental strain. Furthermore, the evolved populations slowed down their citrate consumption at low pH without impacting malolactic performance.

Effect of two starters (Jiu Yao) on Chinese rice wine microbial community and flavour

SummaryThe starters (Jiu Yao) play key roles in the fermentation of rice wine. However, the microbial composition in the starters and their impact on the dynamic changes in the microbial community during the fermentation of Chinese rice wine (CRW) remain unknown. This study aimed to investigate the microbial community structure in different stages of CRW fermentation with two starters (Q1 and Q2) using high‐throughput sequencing approaches. The β‐diversity analysis showed significant differences in fungal components during fermentation, but no significant differences in bacterial composition. Saccharomyces, Aspergillus, Wickerhamomyces and Hyphopichia were the dominant fungal genera. Pediococcus and Weissella were the main bacterial genera. In addition, the ethanol content of wine fermented with Q1 starter (13.33%) is not as high as that of wine made with Q2 starter (14.57%). The total sugar concentration of Q1 and Q2 starters fermentation broth (HJ‐1 and HJ‐2) is 22.74 and 30.20 g L−1, respectively. The correlation analysis showed 11 dominant microbial genera are strongly related to 27 volatile compounds in HJ‐1, and seven dominant microbial genera are strongly related to 18 volatile compounds in HJ‐2. In conclusion, this study indicated that CRW brewed with different starters have different flavour profiles.

Preparation and Application of Directed Vat Set Indigenous Freeze-Drying Lentilactobacillus hilgardii Q19 Starter in Winemaking

In order to prepare a better direct vat set for malolactic fermentation (MLF) in high ethanol and low pH wines, the high-ethanol- and low-temperature-tolerant strain Lentilactobacillus hilgardii Q19, which was isolated from the eastern foothill of the Helan Mountain wine region in China, was used to prepare a direct vat set by vacuum freeze-drying. A superior freeze-dried lyoprotectant was obtained to create the starting culture by selecting, combining, and optimizing numerous lyoprotectants with higher protection for Q19 by using a single-factor experiment and response surface approach. Finally, the Lentilactobacillus hilgardii Q19 direct vat set was inoculated in Cabernet Sauvignon wine to carry out MLF on a pilot scale, with commercial starter culture Oeno1 as control. The volatile compounds, biogenic amines, and ethyl carbamate content were analyzed. The results showed that a combination of 8.5 g/100 mL skimmed milk powder, 14.5 g/100 mL yeast extract powder, and 6.0 g/100 mL sodium hydrogen glutamate offered better protection; with this lyoprotectant, there were (4.36 ± 0.34) × 1011 CFU/g cells after freeze-drying, and it showed an excellent ability to degrade L-malic acid and could successfully finish MLF. In addition, in terms of aroma and wine safety, compared with Oeno1, the quantity and complexity of volatile compounds were increased after MLF, and biogenic amines and ethyl carbamate were produced less during MLF. We conclude that the Lentilactobacillus hilgardii Q19 direct vat set could be applied as a new MLF starter culture in high-ethanol wines.