Search Results (178)

Background: Premium table grapes are often underutilized for winemaking due to suboptimal sugar–acid balance and limited aroma complexity. This study evaluated the chemical and sensory characteristics of wine produced through mixed fermentation of yeasts and lactic acid bacteria (LAB) to valorize Kyoho grapes. Methods: Kyoho grapes were fermented using a sequential yeast inoculation (Hanseniaspora opuntiae followed by Saccharomyces cerevisiae, HO+SC), combined with either simultaneous (SIM-MLF) or sequential (SEQ-MLF) malolactic fermentation using Lactoplantibacillus plantarum. Volatile compounds were quantified via Gas Chromatography with Flame Ionization Detection (GC-FID), and consumer sensory evaluation was conducted. Results: The HO +SC fermentation increased total ester content 4.21-fold compared to the S. cerevisiae control (p < 0.05). SIM-MLF yielded significantly higher levels of ethyl lactate, diethyl succinate, and diacetyl than SEQ-MLF (p < 0.05), with total esters reaching 267.38 ± 17.71 mg/L. Both MLF treatments reduced titratable acidity and increased pH. Conclusions: Sensory evaluation confirmed that SIM-MLF achieved the highest overall acceptance (7.63/9), strongly associated with “floral,” “blackberry,” and “creamy” descriptors. Thus, SIM-MLF effectively enhances the sensory attributes of Kyoho wine, providing a practical valorization strategy for non-traditional grape varieties. Full article

Sparkling wines are produced through a second fermentation of a base wine, whose composition strongly determines the final product quality. Yeast selection for primary fermentation is therefore crucial, as it influences both fermentation performance and sensory attributes. In this study, 156 yeasts were isolated from spontaneous fermentations of Vitis vinifera cv. Torrontés sanjuanino from Paraje de Hilario (1550 m.a.s.l., San Juan, Argentina), aiming to select autochthonous strains with oenological potential for sparkling base wine production. Isolates were phenotypically characterized and molecularly identified by sequencing the D1/D2 domain of the 26S rDNA. A total of 44 Saccharomyces cerevisiae and 60 non-conventional yeasts, mainly Hanseniaspora uvarum, were identified. Based on relevant oenological traits, two S. cerevisiae (M138M, F172M) and two H. uvarum (Mi14M, C135MJ) strains were selected. Laboratory and pilot-scale co-inoculation trials showed that the Mi14M/M138M (50:50) combination exhibited stable fermentation kinetics, low acetic acid production (0.44 g/L), high glycerol levels (7.1 g/L), and suitable pH (3.08) and ethanol content (11.2% v/v). Despite higher residual sugars than the control, no technological issues were observed. These findings support co-inoculation of autochthonous strains of S. cerevisiae and H. uvarum as a promising strategy to enhance wine quality and reinforce regional identity in sparkling base wines. Full article

This scoping review maps and synthesizes scientific evidence on the use of non-Saccharomyces yeasts in wine fermentation, focusing on their contribution to ester formation and aroma modulation. The review followed the Joanna Briggs Institute (JBI) methodology and the PRISMA-ScR guidelines. A total of 71 original articles published between 2000 and 2025 were included, and evidence mapping was combined with an exploratory textual analysis of abstracts using Iramuteq^® to characterize thematic trends, methodological approaches, and knowledge gaps. The textual analysis highlighted fermentation ecology, inoculation strategies, and aroma modulation as central themes, with ester formation emerging as a key topic. Torulaspora, Hanseniaspora, Lachancea, Metschnikowia, and Candida/Starmerella were the most frequently investigated genera, reflecting their potential to diversify wine sensory profiles beyond those typically associated with Saccharomyces cerevisiae fermentations. Non-Saccharomyces yeasts proved particularly relevant in the synthesis and modulation of ethyl and acetate esters linked to fruity and floral characteristics, especially in mixed fermentations. Key knowledge gaps include the limited transferability of laboratory-scale results to industrial conditions, insufficient understanding of interspecies interactions, and the need for stronger sensory validation of volatile compounds. These findings highlight the potential of non-Saccharomyces yeasts as tools for innovation, terroir expression, and enhanced sensory complexity in winemaking. Full article

Non-Saccharomyces yeasts (NSY) are increasingly investigated as biotechnological tools to diversify wine profiles and modulate fermentation outcomes. This study evaluated the enological behavior of two Chilean isolates, Starmerella bacillaris (SB) and Hanseniaspora uvarum (HU), in Sauvignon Blanc must from the Casablanca Valley under monoculture and sequential inoculation (NSY → Saccharomyces cerevisiae) at laboratory (500 mL) and microvinification (10 L) scales. In synthetic medium (150 g/L sugars), SB and HU showed incomplete sugar consumption, producing 4.25% and 8.50% v/v ethanol, respectively, compared with 9.16% v/v for S. cerevisiae. In laboratory-scale fermentation in real must, both strains completed fermentation in monoculture, with moderate reductions in ethanol production relative to the control. At the microvinification scale, monocultures yielded lower ethanol concentrations (11.90–12.50% v/v) than S. cerevisiae (13.50% v/v), whereas sequential fermentations converged toward control values. NSY treatments showed higher relative abundances of medium-chain ethyl esters associated with fruity and floral sensory attributes while maintaining acetic acid concentrations ≤ 0.50 g/L. These findings indicate that the effects of SB and HU depended primarily on fermentation strategy and process scale under the evaluated conditions. Full article

Pear fruits host diverse microbial communities that influence postharvest quality, spontaneous fermentation, and susceptibility to microbial contamination. This study characterizes the fungal communities associated with naturally fallen overripe pears (Pyrus communis) using ITS2 amplicon sequencing combined with culture-dependent approaches. The fungal community exhibited low diversity and was dominated by Ascomycota (99%), primarily Saccharomycetes (91.8%), with Hanseniaspora, Aureobasidium, and Microcyclospora representing more than 90% of the total microbial community. Culture-dependent isolation confirmed Hanseniaspora uvarum as the dominant yeast species (~89%), followed by Metschnikowia spp. and Pichia spp. Pairwise co-culture assays, quantified using the Relative Interaction Index, demonstrated predominantly competitive interactions, with fast-growing H. uvarum exerting suppressive effects on slower-growing species. Among the isolated yeasts, Metschnikowia fructicola exhibited antibacterial activity against all tested bacteria Staphylococcus aureus, Listeria innocua and Salmonella typhimurium. The strongest antibacterial activity was exerted against the foodborne pathogen S. aureus. In a pear juice model system, co-cultivation with M. fructicola resulted in the elimination of S. aureus within four days, while yeast viability was maintained. These findings observe the fermentative yeasts distributed in overripe pears and demonstrate the potential of M. fructicola to inhibit bacterial growth under controlled conditions. The results provide a preliminary basis for further studies on fungal succession, yeast interactions, and the biocontrol potential of pear-associated yeasts. For broader ecological conclusions, larger-scale studies across locations, seasons, cultivars, and decay stages are required. Full article

Pigskin, a major byproduct of pork processing, has high protein content and low fat, endowing it with considerable market value for food applications. In this study, bioaugmented fermentation with Latilactobacillus sakei YBZY-W5, a strain previously isolated from traditional fermented pigskin, was applied to pigskin to systematically evaluate its effects on physicochemical parameters, microbial community succession, and volatile flavor compound (VFC) profiles over 20 days. The results showed that moisture and pH significantly decreased, while total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARSs) increased with fermentation time. High-throughput sequencing revealed that Lactobacilli, Fusarium and Aspergillus dominated early fermentation and were gradually replaced by Bacillus, Hanseniaspora and Debaryomyces. A total of 493 VFCs were identified, among which terpenoids, heterocyclic compounds, and alcohols were the most abundant classes. Orthogonal partial least squares discriminant analysis (OPLS-DA) identified numerous differentially changed VFCs (DCVFCs) during fermentation. Odor activity value (OAV) analysis indicated that green, meaty, and woody notes dominated initially, while sour, floral, sweet, and fruity characteristics became increasingly prominent after fermentation. Pearson correlation analysis demonstrated significant associations between key microorganisms (Lactobacilli, Bacillus, Hanseniaspora, Debaryomyces) and DCVFCs (e.g., β-myrcene, ethyl hexanoate, hexanoic acid, ethyl ester, pyrazines). Collectively, bioaugmented fermentation with Ltb. sakei YBZY-W5 effectively modulated the physicochemical and microbial profiles of pigskin, enriched desirable flavor compounds, and reduced unpleasant odor, confirming its feasibility for producing high-quality fermented pigskin products. This study provides an experimental basis for the value-added utilization of pigskin and promotes sustainable development of the pork industry. Full article

The present study examined for the first time the effect of native yeasts on the fermentation of artisanal Spondias purpurea L., wine produced in Santa Elena, Ecuador. To achieve this goal, three inoculation strategies were compared: a mixed culture containing Saccharomyces cerevisiae and Candida spp. (CLX), commercial S. cerevisiae (CL), and a spontaneous fermentation without added inoculum (SL). Five yeast isolates were identified from the fermentations, four belonging to Candida spp. and one to Kloeckera spp., using microbiological and biochemical methods. The CLX treatment showed the greatest yeast proliferation on PDA plates (2.7 × 10⁶ CFU/mL) and yielded the highest levels of higher alcohols, while the CL treatment produced the highest ethanol (3.72% ABV) and glycerol content (0.46%). All treatments were free of total and fecal coliforms, and their pH values (2.49–2.56) satisfied the requirements of the current Ecuadorian standard for wine production NTE INEN 374. Residual glucose content was specifically quantified using an enzymatic colorimetric (GOD-POD) assay, confirming the dry character of the wines. Molecular analysis of the final preparation obtained from the variant corresponding to the spontaneous fermentation without inoculum (SL) confirmed the presence of Hanseniaspora spp. (Kloeckera spp.), Diutina rugosa (C. rugosa), C. zeylanoides and Pichia kudriavzevii, after the obtained PCR amplicons using ITS1 and ITS4 were subjected to a blast analysis. Sensory evaluation by panelists (n = 15) favored the CLX wine, particularly for aroma and flavor attributes. The final glucose content reached a low value of 0.28 g/L, indicative of an extremely dry wine, with almost no fermentable sugar. Due to the lack of information related to wines produced from Spondias purpurea L., this study could contribute to a better understanding of the biological behavior and biodiversity of the microorganisms present in this fermentation process. These findings will help to improve wine regionality production, supporting the potential application of native regional yeasts in Spondias purpurea L. wine biotechnology. Full article

Criolla grape varieties are native South American cultivars that represent an important reservoir of genetic and microbiological diversity. This study aimed to investigate the oenological potential of Saccharomyces and non-Saccharomyces yeasts isolated from three criolla grape varieties in order to support the future design of wine starters. Yeasts were isolated at different fermentation stages from four vineyards in Mendoza, Argentina. A total of 485 isolates were recovered and molecularly identified, revealing 12 species belonging to eight genera. Saccharomyces cerevisiae, Hanseniaspora guilliermondii and Hanseniaspora uvarum were the dominant species. Isolates were screened for H₂S and acetic acid production, followed by physiological and enzymatic characterisation. Selected strains were further evaluated in small-scale fermentations to assess fermentative kinetics and metabolic performance. Significant variability was observed, particularly among non-Saccharomyces isolates, which generally exhibited lower ethanol yields and acetic acid production compared to S. cerevisiae. Several isolates of H. guilliermondii showed balanced fermentative behaviour and favourable metabolic and enzymatic profiles. Through the applied selection strategy, twelve strains emerged as promising wine starter candidates. These isolates combined a low production of undesirable metabolites, relevant enzymatic activities, and favourable fermentative performance. Overall, the results highlight the oenological potential of autochthonous yeasts as a resource for innovative winemaking strategies. Full article

Water-soluble carbohydrate (WSC) is the key to producing quality forage silage and an important energy source for ruminants. The aim of this study was to investigate the effect of different silages used as roughage sources [whole-plant sugarcane silage (WSS) vs. elephant grass silage (EGS)] with varying levels of WSC on silage quality, buffalo growth performance, apparent digestibility, rumen fermentation, and microbial communities. Sixteen healthy male crossbred buffaloes were randomly divided into two treatment groups, with eight buffaloes/treatment. One group was fed whole-plant sugarcane silage, and the other group was fed elephant grass silage. Compared with EGS, WSS had higher WSC, lactic acid, and ethanol, but lower pH, ammonia nitrogen, propionic acid, and butyric acid (BA) contents (p < 0.05). Potential probiotics (e.g., Lactiplantibacillus and Hanseniaspora) were more abundant in WSS than in EGS (p < 0.05). Moreover, the feed conversion rate was higher in HWS (p < 0.05). However, rumen fermentation parameters were unaffected by diet (p > 0.05). Moreover, feeding WSS had lower dry matter digestibility (DMD), organic matter digestibility (OMD), and lower acid detergent fiber digestibility (ADFD) (p < 0.05). After WSS feeding, ruminal Treponema_2 was strongly associated with DMD, OMD, and ADFD (p < 0.05), and also showed positive correlations with BA and PA contents in WSS (p < 0.05). Additionally, rumen Ruminiclostridium_5 and Pseudozyma was associated with DMD and ADFD after being fed EGS (p > 0.05), respectively, but the Pseudozyma was associated with BA (p < 0.05) and Clostridium_sensu_stricto_11 (p > 0.05) in EGS. Our findings indicated that WSS exhibited superior fermentation quality and harbored potential beneficial microbes, whereas EGS showed higher apparent nutrient digestibility in buffalo but also contained undesirable bacteria (e.g., Clostridium_sensu_stricto_11). Future research should investigate the long-term effects of WSS feeding on buffalo health, immunity, and production performance, as well as its impact on rumen microbiota stability, to fully assess its potential as a safe and sustainable roughage source. Full article

Spontaneously fermented wines are a habitat for many Saccharomyces and non-Saccharomyces strains that are typical for a given region. The isolates obtained can serve as regional starter cultures for winemaking. The aim of this study was to isolate, identify and evaluate the oenological properties and fermentation suitability of selected yeast isolates obtained from Polish spontaneously fermented grape wines. The isolated yeasts were genetically identified and characterised in terms of ethanol tolerance, enzymatic activities, H₂S production, and preliminary killer activity. In small-scale fermentations conducted in CDGJ medium and grape juice, the fermentation rate, pH, number of yeast, content of sugars, ethanol, organic acids and volatile compounds were determined. Genetic identification revealed the species: Saccharomyces cerevisiae, S. paradoxus, Metschnikowia pulcherrima, M. ziziphicola, Hanseniaspora uvarum, and Pichia kluyveri. Non-Saccharomyces and Saccharomyces strains grew poorly in the presence of 4–6% (v/v) and 14–16% (v/v) ethanol, respectively. The yeasts had varied enzymatic activities in API ZYM tests, and production of H₂S, but did not exhibit killer activity. The monocultures showed differences in fermentation rates. The best growth was recorded for all strains during grape juice fermentation, up to 10⁹ cfu/mL, producing ethanol and glycerol in the range of 53.92–86.54 g/L and 0.0–4.48 g/L. Yeasts produced characteristic volatile compounds, e.g., esters: 2-phenylethyl acetate and ethyl decanoate. The monocultures of isolated yeasts can be used in fermentation of grape must, yielding wines with diverse characteristics in terms of ethanol, organic acids and volatile compounds. Full article

Excessive acidity restricts the utilization of citrus pulp, a major by-product of the dried tangerine peel industry. To overcome this bottleneck, a functional microbial consortium (BsHpMrF) comprising Bacillus subtilis L4, Hanseniaspora pseudoguilliermondii B4, and Monascus ruber CGMCC 10910 was constructed for efficient biological deacidification. The consortium exhibited a synergistic effect, achieving an 88.23% reduction in total acidity and converting the acidic pulp into a neutral, bio-stabilized substrate. Untargeted metabolomics analysis revealed that this efficiency was driven by the concurrent activation of the TCA cycle and glyoxylate shunt for organic acid mineralization, coupled with membrane lipid remodeling (increased unsaturation) to enhance acid tolerance. Notably, the fermentation process functioned as a “metabolic factory”, significantly enriching the matrix with bioactive lipids (e.g., 10-HDA, nervonic acid) and indole-3-acetic acid (IAA, 414.28 mg/L). Application assays demonstrated that the fermentation products acted as a potent biostimulant for soybean sprouts, significantly promoting lateral roots and eliciting the accumulation of antioxidant phenolics and flavonoids. This study provides a sustainable “waste-to-treasure” strategy, valorizing acidic citrus pulp into a functional biostimulant for high-quality edible sprout production, thereby achieving a sustainable “waste-to-food” circular loop. Full article

This study evaluated olive leaves from three cultivars (Hojiblanca, Picual, and Arbequina) and olive pomace as complementary sources of bioactive compounds, comparing ultrasound-assisted extraction using organic solvents (UAE) with supercritical CO₂ extraction (SFE). The aim was to determine how the plant matrix and extraction method influence phytochemical composition and functional properties, including antioxidant and antimicrobial activity. The results showed that both factors strongly affected extract composition and bioactivity. UAE favored the recovery of phenolic compounds associated with antioxidant activity, particularly in leaf extracts, while SFE promoted a distinct compositional profile enriched in flavonoids and lipophilic constituents, especially in olive pomace. Multivariate analysis confirmed a clear differentiation between matrices and extraction methods. Leaf extracts from Picual and Arbequina were mainly associated with phenolic compounds linked to antioxidant activity, including luteolin, ethyl vanillin, tyrosol, and isorhamnetin-3-O-glucoside. In contrast, olive pomace extracts were more strongly associated with flavonoids and lipophilic metabolites, such as triterpenes (oleanolic, maslinic, and ursolic acids) and lipid derivatives (oleic acid and lauric isopropanolamide). These compositional differences were reflected in biological activity: UAE extracts showed higher antioxidant activity, whereas SFE extracts, enriched in lipophilic and triterpenic compounds, exhibited stronger antimicrobial effects against Pseudomonas savastanoi and Hanseniaspora sp. Overall, these findings demonstrate that extraction-driven selectivity enables the production of olive-derived extracts with targeted functionalities, with UAE favoring antioxidant-oriented extracts and SFE promoting extracts enriched in lipophilic compounds with antimicrobial potential, particularly from olive pomace. Full article

Hanseniaspora uvarum, formerly known as Kloeckera apiculata, is the predominant yeast species in grape musts for most wine fermentations worldwide. Despite its important impact on wine quality, its genetics has only been studied in some detail within the past decade, and methods for targeted manipulations first emerged in 2021. Since then, they have been improved and extended not only with respect to the wide applications of H. uvarum in beverage industries and as an environmental control agent, but also as tools in basic genetic research. In this review, the latest developments and future perspectives are summarized. Full article

Grape harvest time influences the berry composition, which impacts the organoleptic wine characteristics. Winemakers monitor technological, phenolic, and aromatic grape maturity to decide the harvest date. Little is known about the evolution of yeast ecology of grapes during the maturation period. The microbiota involved in the fermentation impacts the wine composition and characteristics; therefore, changes in grape biodiversity could have an impact in fermentation kinetics and aroma compound formation. In this study, the yeast biodiversity of Grenache Noir and Carignan grapes from Montsant DO (Denomination of Origin) were analyzed at different ripening stages to assess how harvest time influences microbiota. The fermentation performance of the yeasts obtained was studied at both laboratory and pilot scales to evaluate the impact of these yeasts, both in pure and mixed cultures, on the wine’s chemical and aromatic composition as well as its sensory impact. The results indicated that early harvest favored a higher diversity of non-Saccharomyces species, whereas in more mature grapes, Saccharomyces cerevisiae species was dominant. The isolated strains of Saccharomyces differed in their fermentation performances, as well as ethanol content and acidity of wine. In general, they produced higher concentration of fermentative volatile compounds than a commercial strain. The non-Saccharomyces yeasts in mixed fermentations with the S. cerevisiae strains also impacted wine composition and characteristics, leading lower ethanol content or enhancing aromatic balance and sensory equilibrium. The results highlight that grape harvest timing influences microbial diversity and fermentative performance and thus should be considered to better determine the optimum harvest date and ensure consistent wine characteristics. Full article

This research study investigated the potential biotechnological applications of yeast species obtained from cocoa fermentation performed in Côte d’Ivoire. A total of 279 yeast isolates were molecularly identified and then screened for their antifungal ability against various Aspergillus species and for the production of aromatic compounds and extracellular enzymes. Thirty-one yeast species belonging to nineteen genera, dominated by Pichia, Candida, Hanseniaspora, and Rhodotorula, were isolated from fermented cocoa beans. All extracellular enzymes screened were produced by most yeast species, except β-glucanase and esterase activity, whereas the most common enzyme was β-glucosidase. Yeasts of the Pichia, Saccharomyces, Candida, Clavispora, and Hanseniaspora genera produced various enzymes, including xylanase, β-glucosidase, polygalacturonase, invertase, pectinase, and chitinase. The 88 aromatic compounds produced were grouped into five main chemical families, including esters, alcohols, acids, aldehydes, and ketones. Wickerhamomyces anomalus was the highest producer of major desirable aromatic compounds, including alcohols, ketones, and esters. All yeast species showed a specific antagonistic effect against the growth of various Aspergillus species, but Candida incommunis, Saccharomyces cerevisiae, and Torulaspora delbrueckii recorded the greatest antifungal ability. These yeast species could be used to develop promising starter cultures to improve the organoleptic quality of various fermented foods and beverages. Full article