Wine Fermentation Research Articles

Utilization of coffee by-products for the production of alcoholic and non-alcoholic beverages and their physiochemical and sensory characteristics

Coffee pulp is the first byproduct of coffee processing. It contains contaminants due to its composition and production volume. This study evaluates coffee by-products wine from fresh coffee pulp, used as a substrate, along with cascara tea from dried coffee pulp. About 40 % of pulp was obtained during the wet processing of coffee. The pulp was dried directly in the sun for 3–4 days until the moisture content of the cascara drink was below 8 %. Similarly, for the alcoholic beverage (wine), the must was processed to the TSS (24°Brix), and the fermentation process was carried out for up to 10–12 days until the TSS was down to 10°Brix. After the fermentation was completed, the fermented wine was kept for secondary fermentation where it undergoes aging or clarification. The clarified wine was then filled into sterilized glass bottles for further use. The chemical composition of coffee pulp (moisture, ash, crude protein, acidity, fat, crude fiber, caffeine, tannin, reducing sugar, TSS, and flavonoids) was analyzed. Both beverages were also subjected to sensory analysis and chemical analysis Caffeine, tannin, pH, and acidity of the non-alcoholic beverage were 220 mg/L, 45.7 mg/L, 4.16 and 1.24 %, respectively. Alcohol, methanol, ester, aldehyde, pH, TSS, acidity, caffeine, tannin, and flavonoid were 10.58 ABV %, 295 mg/L, 75.26 ppm, 10.12 ppm, 3.2, 10°Brix, 0.52 %, 28.96 ppm, 280 mg/L and 405 mg/g, respectively. The alcoholic and non-alcoholic beverages made from coffee pulp were superior in terms of sensory attributes. Therefore, it is possible to develop both beverages from coffee pulp and maximum utilization of waste coffee pulp

Influence of an indigenous yeast, CECA, from the Ningxia wine region of China, on the fungal and bacterial dynamics and function during Cabernet Sauvignon wine fermentation.

Saccharomyces cerevisiae CECA was a potential indigenous Chinese wine yeast that can produce aroma and flavor in Cabernet Sauvignon wines. High-throughput sequencing combined with metabolite analysis was applied to analyze the effects of CECA inoculation on the native microbial community interaction and metabolism during Cabernet Sauvignon wine fermentation. Fermentations were performed with three different inoculant strategies: spontaneous fermentation without inoculation, inoculation with CECA after grape must sterilization, and direct inoculation of CECA. Results showed that the diversity of bacteria (P = 0.033) is more sensitive to CECA inoculation than fungi (P = 0.563). In addition, CECA inoculation altered the species composition of core microorganisms (relative abundance >1%) and the keystone species (accounting for the top 1% of the most important interactions), as well as of the biomarkers (linear discriminant analysis > 3.0, P < 0.05). Furthermore, the inoculation could change the cluster of metabolites, and these differential metabolite sets were correlated with four fungal taxa of Issatchenkia, Issatchenkia orientalis, Saccharomycetales, Saccharomycetes and two bacterial taxa of Pantoea, Tatumella ptyseos, were significantly correlated. Inoculated fermentation also altered the correlation between dominant microorganisms and aroma compounds, giving Cabernet Sauvignon wines more herbal, floral, fruity, and cheesy aromas. Saccharomyces cerevisiae CECA and dimethyl dicarbonate (DMDC) inhibition treatments significantly altered the microbial community structure of Cabernet Sauvignon wines, which in turn affected the microbial-metabolite correlation. These findings will help winemakers to control the microbial dynamics and functions during wine fermentation, and be more widely used in regional typical wine fermentations. © 2024 Society of Chemical Industry.

Impact of biodynamic and organic vineyard management on the microorganism community and aroma characteristics of cabernet sauvignon wine

Researchers and winemakers have recently paid more attention to biodynamic (BDN) and organic (ORG) vineyard management to produce more healthy and regional wines. However, little attention has been paid to the correlation between agricultural systems, microbiota, and wine quality in biodynamic and organic wines in Ningxia, China. In this study, volatiles of wine and microorganism diversities during the wine fermentation using Cabernet Sauvignon grapes from vineyards of biodynamic, non-dynamics (BNDc, i.e., conventional one which was close to BND, considered to be a control of BND), organic, and non-organic (ORGc, i.e., conventional one which was close to BND, considered to be a control of ORG) in Ningxia, China were investigated. Hanseniaspora uvarum, Cladosporium sp., and Alternaria alternata were the main three fungal species, and Lactobacillus kunkeei, Citrus maxima, and Tatumella ptyseos were the main three bacterial species. Surprisingly, BDNc and ORG showed a significantly higher diversity of fungal communities than BDN and ORGc. The network in BDNc was the most complex, with the highest average degree and density and a higher clustering coefficient. Managing biodynamic and organic vineyards could result in floral, herb, spice, and medium floral aromas with low temperate fruit, tropical fruit, and berry flavors to wines. The correlation between agricultural systems, microbiota, and wine sensory systems showed that lactic acid bacteria (Lactobacillus) played critical roles in ORG and BDN by offering pleasant sensory and nutritional benefits. Moreover, Nowamyces globulus, Hanseniaspora uvarum, Lactobacillus johnsonii, Fusarium sp., Microterricola viridarii, Citrus maxima, Sphingomonas faeni, Cladosporium sp., Cladosporium ramotenellum, Cladosporium cladosporioides, Kodamaea ohmeri and Lactobacillus plantarum were positively correlated with aroma compounds. This study improves our understanding of the influence of vineyard management on microorganism succession and wine characteristics, providing a reference and scientific basis for the development of BDN and ORG wines.

Effect of Different Yeasts on the Higher Alcohol Content of Mulberry Wine.

Healthy, nutritious, and delicious mulberry wine is loved by everyone, but there is no specific yeast for mulberry wine. To screen for yeasts with low-yield higher alcohols for the fermentation of mulberry wine, we tested five commonly used commercial yeasts available on the market to ferment mulberry wine. All five yeasts were able to meet the requirements in terms of yeast fermentation capacity, speed, and physical and chemical markers of mulberry wine. The national standards were met by the fermentation requirements and the fermented mulberry wine. We identified yeast DV10 as a yeast with low-yield higher alcohols suitable for mulberry wine fermentation. The total higher alcohol content in fermented mulberry wine was 298 mg/L, which was 41.9% lower than that of fermented mulberry wine with yeast EC118. The contents of 17 free amino acids and five sugars in mulberry juice and five yeast-fermented mulberry wines were tested. The results showed that the higher the amino acid and sugar content in yeast-fermented mulberry wine, the higher the content of higher alcohols produced by fermentation. A correlation analysis performed on each higher alcohol produced when yeast DV10 fermented the mulberry wine indicated decreased sugar and related amino acids. The findings demonstrated a substantial negative correlation among the levels of increased alcohol, decreased sugar, and matching amino acid content. Considering the correlation values among increased alcohol, decreased sugar, and related amino acids, the very slight difference suggests that both sugar anabolism and amino acid catabolism pathways have an equivalent impact on the synthesis of higher alcohols during the fermentation of mulberry wine. These results provide a theoretical basis for reducing the content of higher alcohols in mulberry wines, given the history and foundation for producing mulberry wine.

Dynamic transformation in flavor during hawthorn wine fermentation: Sensory properties and profiles of nonvolatile and volatile aroma compounds coupled with multivariate analysis

Fermentation stage is a crucial factor for flavor profiles formation of hawthon wine. Thus, comprehensive knowledge of dynamic relationship between nonvolatile (NVOCs) and volatile aroma compounds (VOCs) from hawthorn wine at different fermentation stages was investigated by GC–MS and HPLC coupled with multivariate analysis. The increase of alcohols/esters/acids but decrease of terpenes/aldehydes/ketones was observed as fermentation extension. Specifically, OAV of ethyl acetate, ethyl caprylate, and ethyl caprate was > 50 from the 3rd day to 10th day, giving more fruity properties. Multivariate analysis showed that 1-hexanol, ethyl myristate, isobutyric acid, et al., were linked to the sensory evaluation of “sweet”, “floral” and “fruity”, and fructose, glucose and bitter amino acids were responsible for reduction of “bitterness” and “astringency”. Additionally, VOCs were positively correlated with organic acids while negative to amino acids/soluble sugars, probably due to metabolization as precursors, providing references for aroma enhancement by regulating NVOCs precursors.

Comparison of Aroma and Taste Profiles of Kiwi Wine Fermented with/without Peel by Combining Intelligent Sensory, Gas Chromatography-Mass Spectrometry, and Proton Nuclear Magnetic Resonance.

Kiwi wine (KW) is tipically made by fermenting juice from peeled kiwifruit, resulting in the disposal of peel and pomace as by-products. However, the peel contains various beneficial compounds, like phenols and flavonoids. Since the peel is edible and rich in these compounds, incorporating it into the fermentation process of KW presents a potential solution to minimize by-product waste. This study compared the aroma and taste profiles of KW from peeled (PKW) and unpeeled (UKW) kiwifruits by combining intelligent sensory technology, GC-MS, and 1H-NMR. Focusing on aroma profiles, 75 volatile organic compounds (VOCs) were identified in KW fermented with peel, and 73 VOCs in KW without peel, with 62 VOCs common to both. Among these compounds, rose oxide, D-citronellol, and bornylene were more abundant in UKW, while hexyl acetate, isoamyl acetate, and 2,4,5-trichlorobenzene were significantly higher in PKW. For taste profiles, E-tongue analysis revealed differences in the taste profiles of KW from the two sources. A total of 74 molecules were characterized using 1H-NMR. UKW exhibited significantly higher levels of tartrate, galactarate, N-acetylserotonin, 4-hydroxy-3-methoxymandelate, fumarate, and N-acetylglycine, along with a significantly lower level of oxypurinol compared to PKW. This study seeks to develop the theoretical understanding of the fermentation of kiwifruit with peel in sight of the utilization of the whole fruit for KW production, to increase the economic value of kiwifruit production.

Application of white wine lees for promoting lactic acid bacteria growth and malolactic fermentation in wine

Application of white wine lees for promoting lactic acid bacteria growth and malolactic fermentation in wine

Dynamics and correlation between volatile compounds and microbial community in chestnut rice wine fermentation

SummaryChestnut rice wine, also called banli mijiu (BLMJ), uses Chinese chestnut (Castanea mollissima Blume) in the fermentation of traditional glutinous rice wine. This study characterised the microbial communities and volatile compounds in BLMJ and explored their correlations. Headspace solid‐phase microextraction‐gas chromatography–mass spectrometry (HS‐SPME‐GC–MS) revealed that the major volatile compounds during BLMJ fermentation include eighteen important volatile compounds (OAV &gt; 1). High‐throughput sequencing (HTS) demonstrated that the abundance and diversity of bacteria were significantly greater than those of fungi during the fermentation process. Among them, Kropensteria and Saccharomyces were the most abundant bacteria and fungi at the genus level during the fermentation of BLMJ. Spearman's correlation analysis revealed that eighteen important volatile compounds were significantly positively correlated with seven microbial genera (|r| &gt; 0.9, P &lt; 0.01), including six bacterial genera (Rhodococcus, Lactococcus, Pseudomonas, Janthinobacterium, Unclassified_f_Bacillaceae and Burkholderia‐Caballeronia‐Paraburkholderia) and one fungal genus (Saccharomyces). Therefore, these bacterias and fungi may be core functional microorganisms during BLMJ fermentation. The findings may provide important reference for mediating the microbial community during fermentation to improve the flavour of BLMJ.

Synergistic Fermentation of Pichia kluyveri and Saccharomyces cerevisiae Integrated with Two-Step Sugar-Supplement for Preparing High-Alcohol Kiwifruit Wine.

Wild yeast suitable for kiwifruit wine fermentation was isolated and purified, and the fermentation process was optimized to increase the alcohol content of the kiwifruit wine. Pichia kluyveri was isolated from kiwifruit pulp by lineation separating, screened by morphological characteristics in Wallerstein Laboratory Nutrient Agar (WL) medium and microscope observation, and further identified by 26S rDNA D1/D2 domain sequence analysis. Taking alcohol content and sensory evaluation as two indexes, the fermentation condition for kiwifruit wine was optimized by single factor and response surface experiment. The optimal fermentation conditions were optimized as follows: the fermentation temperature was at 24 °C, the initial pH was 3.8, the sugar dosage in second step was 8% (w/w), and the inoculating quantity of Pichia kluyveri and Saccharomyces cerevisiae was 0.15 g/L at equal proportion. Under these optimal conditions, the maximum estimated alcohol content was 15.6 vol%, and the kiwifruit wine was light green in color with strong kiwifruit aroma and mellow taste.

Integrative metagenomics, volatilomics and chemometrics for deciphering the microbial structure and core metabolic network during Chinese rice wine (Huangjiu) fermentation in different regions

Huangjiu is a spontaneously fermented alcoholic beverage, that undergoes intricate microbial compositional changes. This study aimed to unravel the flavor and quality formation mechanisms based on the microbial metabolism of Huangjiu. Here, metagenome techniques, chemometrics analysis, and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC–MS) metabolomics combined with microbial metabolic network were employed to investigate the distinctions and relationship between the microbial profiles and the quality characteristics, flavor metabolites, functional metabolic patterns of Huangjiu across three regions. Significant variations (P < 0.05) were observed in metabolic rate of physicochemical parameters and biogenic amine concentration among three regions. 8 aroma compounds (phenethyl acetate, phenylethyl alcohol, isobutyl alcohol, ethyl octanoate, ethyl acetate, ethyl hexanoate, isoamyl alcohol, and diethyl succinate) out of 448 volatile compounds were identified as the regional chemical markers. 25 dominant microbial genera were observed through metagenomic analysis, and 13 species were confirmed as microbial markers in three regions. A metabolic network analysis revealed that Saccharomycetales (Saccharomyces), Lactobacillales (Lactobacillus, Weissella, and Leuconostoc), and Eurotiales (Aspergillus) were the predominant populations responsible for substrate, flavor (mainly esters and phenylethyl alcohol) metabolism, Lactobacillales and Enterobacterales were closely linked with biogenic amine. These findings provide scientific evidence for regional microbial contributions to geographical characteristics of Huangjiu, and perspectives for optimizing microbial function to promote Huangjiu quality.

Genome-wide transcriptome analyses reveal changes in glutathione-overproducing yeast obtained by ARTP mutagenesis for rice wine brewing

The atmospheric and room temperature plasma (ARTP) technique efficiently enhances yeast glutathione (GSH) yield. This study focused on obtaining a GSH over-producing strain, Saccharomyces cerevisiae SCZ40, through mutagenesis and stability testing. SCZ40 exhibited a remarkable 71.1% increase in GSH content during rice wine fermentation. Scanning electron microscopy (SEM) and whole-genome sequencing identified ARTP-induced changes in cell morphology and alterations in the protein-serine/threonine kinase and isocitrate dehydrogenase pathways linked to GSH synthesis. Transcriptomic analysis revealed 507 differentially expressed genes, highlighting the impact of ARTP on S. cerevisiae. Up/down-regulated genes associated with glycolysis/gluconeogenesis suggested a shift in glucose distribution favoring the pentose phosphate pathway and positively influencing GSH production. Pathway analysis further elucidated changes in glycolysis/gluconeogenesis, tricarboxylic acid cycle (TCA), and GSH biosynthesis pathways. Validation through quantitative real-time polymerase chain reaction (qRT-PCR) confirmed RNA-seq data reliability.

Models for Wine Fermentation and Their Suitability for Commercial Applications

The ability to model the kinetics of wine fermentation enables the early detection of abnormal, sluggish or stuck fermentations, and the prediction of present and future rates of energy, CO2 and ethanol vapor release. While several wine fermentation models have been published, there are only a few that have been successfully adopted for commercial practice. In this work, the mathematical descriptions of wine fermentation are reviewed and compared. The common features of these include descriptions for the kinetics of yeast growth; substrate and nutrient consumption; product formation; and total and viable cell mass. Additional features include the inhibition of growth by ethanol; competitive inhibition of glucose and fructose uptake; glycerol formation; and the calculation of density from solution composition and solute properties. Three models were selected to compare their ability to describe the sugar, ethanol, biomass and nitrogen of benchtop fermentations at four temperatures, previously published. The models are assessed for their goodness of fit to the data in synthetic-medium fermentations and their suitability for analyzing and predicting commercial wine fermentations.

A Holistic View of the Fate of Berry-Derived Adjuncts throughout Fermentation

Berries and their products can enhance the antioxidant profile, color, and sensory characteristics of beverages, resulting in competitive, value-added products. However, a complete overview of how fermentation affects these compounds is lacking. The American black elderberry, Sambucus canadensis, is an excellent candidate for studying how berry juices are affected during fermentation due to high concentrations of color compounds, anthocyanins, and volatile compounds. Gravity, pH, titratable acidity, total anthocyanins, color, and GC-MS analyses were performed on two varieties of elderberries to examine the physical and chemical qualities of elderberry juice before and after wine fermentation. A commercial product with elderberry adjuncts added post fermentation was also analyzed. The concentration of anthocyanins degraded by ~40% as the color of the elderberry wine shifted from blue to red after fermentation. Products that added elderberries post fermentation did not see the same degradation, however, also did not incorporate the same changes to volatile compounds as observed in the fermented wine. The fermentation industry can use this study’s findings to decide how best to use fruits to improve commercial products.

Up-regulation of Retrograde Response in yeast increases glycerol and reduces ethanol during wine fermentation

Nutrient signaling pathways play a pivotal role in regulating the balance among metabolism, growth and stress response depending on the available food supply. They are key factors for the biotechnological success of the yeast Saccharomyces cerevisiae during food-producing fermentations. One such pathway is Retrograde Response, which controls the alpha-ketoglutarate supply required for the synthesis of amino acids like glutamate and lysine. Repressor MKS1 is linked with the TORC1 complex and negatively regulates this pathway. Deleting MKS1 from a variety of industrial strains causes glycerol to increase during winemaking, brewing and baking. This increase is accompanied by a reduction in ethanol production during grape juice fermentation in four commercial wine strains. Interestingly, this does not lead volatile acidity to increase because acetic acid levels actually lower. Aeration during winemaking usually increases acetic acid levels, but this effect reduces in the MKS1 mutant. Despite the improvement in the metabolites of oenological interest, it comes at a cost given that the mutant shows slower fermentation kinetics when grown in grape juice, malt and laboratory media and using glucose, sucrose and maltose as carbon sources. The deletion of RTG2, an activator of Retrograde Response that acts as an antagonist of MKS1, also results in a defect in wine fermentation speed. These findings suggest that the deregulation of this pathway causes a fitness defect. Therefore, manipulating repressor MKS1 is a promising approach to modulate yeast metabolism and to produce low-ethanol drinks.

Metabolomic analysis reveals the interactions between Chinese indigenous and commercial Saccharomyces cerevisiae strains during wine co-fermentations at low YAN concentration

The successful use of indigenous strains as starter cultures is dependent not only upon their capacity to complete a fermentation but also on their ability to dominate the fermentation. Chinese strain NX11424 was identified as an indigenous Chinese wine strain with commercial potential. Fermentations to assess the ability of NX11424 to compete with a commercial strain, Montrachet (UCDVEN 522), in pure and co-inoculations were performed with exo- and endo-metabolomic analyses. Metabolome analysis was run at three time points (days 2, 4 and 6). The metabolic profiles of all three treatment were similar at day 2. The endo-metabolome of the co-culture most closely resembles that of Montrachet strain at days 4 and 6, while exo-metabolomic data most closely resembles the NX11424 strain at day 6. The levels of key biomarkers among different fermentations varied at different time points, especially in amino acid metabolism; however glycerolipid, sucrose and starch metabolism were consistently most impactful in driving differences across treatment. Sulfur metabolism was also differential among treatments, with higher levels of associated metabolites in Montrachet strain. This study demonstrated the effects of pure and co-starter fermentations on cellular and wine metabolites, which can be helpful for control of wine fermentation and management of desirable wine flavor.

The dynamics analysis of a new wine fermentation model

The dynamics analysis of a new wine fermentation model

Evaluation of physicochemical properties, antioxidant capacity, and volatile flavor compounds during the wine fermentation of Mei (Prunus mume) fruit

In this study, Prunus mume (Mei) wine was produced from the fruits of a new variety Mei ‘Laizhou Mixing’. The optimum process parameters (OPPs) of Mei wine (MW) fermentation were determined through an orthogonal experiment. We explored the physicochemical properties, antioxidant capacity, and volatile flavor compounds (VFCs) of MW and their correlation characteristics. Under the OPPs (A2B2C3D3) condition, MW containing approximately 6% (v/v) alcohol was obtained within three days of fermentation. After seven days of low-temperature clarification, the antioxidant capacity of MW was significantly higher than that of Mei juice, and the VFCs type and concentration significantly increased. A total of eight esters and one phenolic compound were produced during fermentation. The changes in the VFCs of MW were related to physicochemical properties and antioxidant capacity. This study provides insight into the changes in MW quality before and after fermentation.

Development of a defined mixed starter culture for the improvement of Tej, Ethiopian honey wine.

Ethiopian honey wine, Tej, is the most popular traditionally fermented alcoholic beverage in Ethiopia. Owing to the spontaneous fermentation process, the final product is neither predictable nor consistent in quality. Attempts have not been made before to solve this problem. Thus, the aim of this study was to develop a potential mixed starter culture of yeast and lactic acid bacteria isolated from Tej samples for the production of Tej with consistent quality. One hundred seventy-seven lactic acid bacteria and 194 yeasts were isolated from 30 Tej samples collected from southwest Ethiopia. After sequentially testing the isolates towards physiological stress tolerance and desired metabolic products, 10 lactic acid bacteria and 10 yeast isolates were screened. Later, four lactic acid bacteria and four yeast isolates were found to be compatible in co-culture tests. Finally, the combination of lactic acid bacteria and yeast isolates was formulated using the design of expert version 7.0.0 software, and six formulates (F #1-6) were designed. Controlled Tej fermentation was performed under laboratory conditions using six lactic acid bacteria-yeast starter culture formulations. The sensory attributes, in terms of color, flavor, odor, turbidity, and overall acceptance analysis scored 4.8/5.0 (F #2) and 4.7/5.0 (F #6), with mean significant variations (p < 0.05) among the other formulates. These two formulates were considered the best-mixed starter cultures compared to the control and other formulates. Matrix-assisted laser desorption ionization-time of flight analysis revealed that the lactic acid bacteria starters (AAUL7 and AAUL10) belonged to Lactobacillus paracasei. While the yeast starters (AAUY2 and AAUY8) belonged to Saccharomyces cerevisiae. These mixed lactic acid bacteria-yeast starter cultures could be used as the best starter culture for the fermentation of Ethiopian honey wine, Tej, with consistent quality.

Differences in metabolism among Saccharomyces species and their hybrids during wine fermentation.

This study aimed to investigate how parental genomes contribute to yeast hybrid metabolism using a metabolomic approach. Previous studies have explored central carbon and nitrogen metabolism in Saccharomyces species during wine fermentation, but this study analyses the metabolomes of Saccharomyces hybrids for the first time. We evaluated the oenological performance and intra- and extracellular metabolomes, and we compared the strains according to nutrient consumption and production of the main fermentative by-products. Surprisingly, no common pattern was observed for hybrid genome influence; each strain behaved differently during wine fermentation. However, this study suggests that the genome of the S. cerevisiae species may play a more relevant role in fermentative metabolism. Variations in biomass/nitrogen ratios were also noted, potentially linked to S. kudriavzevii and S. uvarum genome contributions. These results open up possibilities for further research using different "omics" approaches to comprehend better metabolic regulation in hybrid strains with genomes from different species.

Unveiling the dynamic microbial succession and metabolic characteristics during traditional fermentation of hainan shanlan rice wine

The objective of this study was to reveal the microbial succession and metabolic characteristics during traditional fermentation of Hainan Shanlan rice wine (HSRW). Correlations between core microorganisms and key metabolites were explored. Four bacterial genera (Pediococcus, Levilactobacillus, Pantoea and Limosilactobacillus) and 3 fungal genera (Saccharomyces, Rhizopus, and Saccharomycopsis) were the dominant in HSRW. Alcohols, esters and organic acids were the main metabolites in the HSRW. 2-Ethyl-1-hexanol, dimethylsilanediol, pentaethylene glycol, ethyl hexadecanoate, ethyl tetradecanoate and (E)-9-octadecenoic acid ethyl ester were identified as the characteristic volatile flavor compounds. Malic acid and lactic acid were the primary organic acids. Spearman correlation analysis revealed that Levilactobacillus and Pediococcus were the core functional microorganisms and exhibited significant associations with key metabolites. This study provides a scientific and practical foundation for elucidating the potential value of core functional microorganisms and for the development of Directed Vat Set in the industrial prodution of HSRW.