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Food Chemistry May 2023To investigate the effects of mixed fermentation with T. delbrueckii on aroma profiles of blueberry fermented beverage, five fermentations were conducted: monoculture of...
To investigate the effects of mixed fermentation with T. delbrueckii on aroma profiles of blueberry fermented beverage, five fermentations were conducted: monoculture of T. delbrueckii and S. cerevisiae, respectively; co-inoculation of two strains; sequential inoculation of two strains at time intervals of 24 h and 48 h, respectively. Compared with pure S. cerevisiae fermentation, ethanol level was decreased by up to 1.1% vol., while total anthocyanins were increased by 27.7%-85.0% in mixed fermentations. Marker aroma compounds in different fermentations with relative odor activity values higher than 1were identified. T. delbrueckii significantly decreased volatile acid content (especially acetic acid) by 22.2%-83.3%. Ethyl 3-methylbutanoate, ethyl hexanoate and ethyl octanoate, in pure T. delbrueckii fermentation were significantly decreased, while their concentrations were increased by 1.6-4.4 folds in sequential fermentations. Besides, linalool, rose oxide, benzeneacetaldehyde were significantly increased by sequential fermentation, which was associated with the enhancement of fruity and sweet notes.
Topics: Saccharomyces cerevisiae; Torulaspora; Wine; Blueberry Plants; Anthocyanins; Fermentation; Acetic Acid
PubMed: 36586265
DOI: 10.1016/j.foodchem.2022.135284 -
Foods (Basel, Switzerland) Nov 2022The use of wild yeasts, isolated from different environments, is becoming the most interesting option for the production of new beers. The objective of this study is to...
The use of wild yeasts, isolated from different environments, is becoming the most interesting option for the production of new beers. The objective of this study is to evaluate the potential of seven non-conventional yeast strains from five different species (, , , , and ) isolated from Madrid agriculture to produce type ale beer. Wild yeast strains were evaluated at laboratory and pilot plant scales under different fermentation conditions (pure, aerated, and sequential culture). Strain SafAle S-04 was used as a reference. Throughout the fermentation of beer, volatile compounds were determined by GC and residual sugars by HPLC, among other parameters. The yeast strains used for the fermentation in pure culture conditions were unable to ferment maltose and maltotriose (0.73-1.18% / of ethanol). The results of the study under aerated conditions showed varying levels of higher alcohol and ester concentrations. It should be noted that the strain CLI 1057 () fermented maltose in the presence of oxygen (Kluyver effect). This strain also showed a high production of 4-vinyl guaiacol, making it suitable for producing beers with a phenolic profile. Finally, three strains (, and ) were evaluated in sequential culture together with commercial strain and found to improve the organoleptic characteristics of the brewed beer. These approaches offer the opportunity to add new product characteristics to the beers.
PubMed: 36429309
DOI: 10.3390/foods11223717 -
Journal of Fungi (Basel, Switzerland) Sep 2022Thai traditional fermented fish products (Plaa-som) from four provinces (Ubon Ratchathani, Surin, Sisaket, and Khon Kaen) in the northeast part of Thailand were...
Thai traditional fermented fish products (Plaa-som) from four provinces (Ubon Ratchathani, Surin, Sisaket, and Khon Kaen) in the northeast part of Thailand were collected and analyzed to determine their salt content, total acidity, and pH. Yeasts in all samples were isolated and identified to the genus and species level based on sequence analysis of the D1/D2 of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region. The results revealed that the salt content, total acidity, and pH values are in the range of 2.01-6.9%, 0.62-1.9%, and 4.4-6.57%, respectively. Moreover, 35 strains of yeast were isolated and identified as eight genera, namely , , and with 17 species. The ascosporogenous yeast, , was the most dominant genus found and was widely distributed among the fermented food samples. In addition, a new strain of yeast, , was also discovered in Plaa-som samples. Thus, this study is the first to report the presence and wide distribution of these yeasts in fish fermentation products.
PubMed: 36294595
DOI: 10.3390/jof8101029 -
Journal of Food Science and Technology Dec 2022Canastra's Minas artisanal cheese [QMA (Minas artisanal cheese)] is a protected geographical indication traditional food. The influence of fungi on the cheese ripening...
Canastra's Minas artisanal cheese [QMA (Minas artisanal cheese)] is a protected geographical indication traditional food. The influence of fungi on the cheese ripening process is of great importance. This study aimed to apply culture-dependent and -independent methods to determine the mycobiota of QMA produced in the Canastra region, as well as to determine its physicochemical characteristics. Illumina-based amplicon sequencing and matrix-assisted laser desorption ionization time-of-flight mass spectrometry were the culture-independent methods used. The physicochemical analysis results showed that the QMA has a moisture content ranging 18.4-28.2%, fat content ranging 20.5-40%, sodium chloride percentage of approximately 0.9%, and pH ranging 5.2-5.5. The population of fungi ranged between 6.3 and 8 log colony-forming unit/g. spp., , spp., , , spp., , , spp., spp. and spp. were the most prevalent fungi. The methods used to evaluate the mycobiota provide a better understanding of which species are present in the final product and eventually contribute to the characteristics of QMA. and . were identified as promising species for future studies on product quality.
PubMed: 36276518
DOI: 10.1007/s13197-022-05548-4 -
Frontiers in Microbiology 2022Non-conventional yeasts such as () have been proposed for sparkling winemaking. Unfortunately, this yeast has poor efficiency in completing wine fermentation as...
Non-conventional yeasts such as () have been proposed for sparkling winemaking. Unfortunately, this yeast has poor efficiency in completing wine fermentation as compared to (). New mutants with increased resistance to SO, ethanol, and high CO pressure were previously isolated from spore clones of . Although these mutants showed improved capability for base wine fermentation, there is still room for genetic improvement of yeasts until the fermentative capacity of is achieved. As an alternative approach, yeast mixture for eventual hybridization of with was assayed in this study. The new yeast mixture clones (-mixed ) showed an intermediate phenotype between both parent yeasts for some relevant biotechnological properties, such as resistance to SO, ethanol, copper, high CO pressure, and high temperature, as well as flocculation potential. These properties varied depending on the specific -mixed clone. Several mixture clones showed improved capability for base wine fermentation as compared to the parent strain, approaching the fermentation capability of the parent strain. The organoleptic quality of sparkling wine was also improved by using some mixture clones and this improved quality coincided with an increased amount of acetate and ethyl esters. The genetic stability of some -mixed clones was good enough for commercial yeast production and winery applications.
PubMed: 36274726
DOI: 10.3389/fmicb.2022.1006978 -
Brazilian Journal of Microbiology :... Dec 2022In recent years, ample research has focused on applying wild (especially non-Saccharomyces) yeasts in producing alcoholic beverages. Common characteristics of wild yeast...
In recent years, ample research has focused on applying wild (especially non-Saccharomyces) yeasts in producing alcoholic beverages. Common characteristics of wild yeast strains include simultaneous high production of fruity and floral aroma compounds and low ethanol production. In this study, mead starter cultures were selected based on preliminary screening of wild yeast strains from a Brazilian culture collection (n = 63) for their ability to produce aroma-active compounds. The selected strains included one strain of Saccharomyces cerevisiae and three non-Saccharomyces strains (Pichia jadinii, Torulaspora delbrueckii, and Kluyveromyces lactis). These strains were used to ferment honey must prepared with Aroeira honey, adjusted to 24°Brix, which took 36 days to complete. Single culture fermentations and co-fermentations with S. cerevisiae and non-Saccharomyces strains were carried out. The quality of the produced beverages was evaluated by sugar consumption and production of alcohols and organic acids, analyzed with high-performance liquid chromatography. The volatile organic compound composition was analyzed with gas chromatography-mass spectrometry. Meads with various ethanol amounts (4.7-11.0% v/v) and residual sugar contents (70.81-160.25 g l) were produced. In addition, in both single-strain fermentation and co-fermentation with S. cerevisiae, meads produced with either Torulaspora delbrueckii or Kluyveromyces lactis had a roughly three-fold higher content of honey-aroma compound phenethyl acetate and a higher hedonic impression score than meads produced with only S. cerevisiae. These results demonstrated non-Saccharomyces yeasts' ability to increase aroma complexity and improve the sensory quality of low-alcoholic meads.
Topics: Odorants; Saccharomyces cerevisiae; Torulaspora; Yeasts; Fermentation; Ethanol; Wine
PubMed: 36269554
DOI: 10.1007/s42770-022-00840-z -
Foods (Basel, Switzerland) Oct 2022There is a lack of studies evaluating the metabolic contribution of non- yeasts in early fermentation phases. This study aimed to investigate the volatile aroma profiles...
There is a lack of studies evaluating the metabolic contribution of non- yeasts in early fermentation phases. This study aimed to investigate the volatile aroma profiles produced by various non- yeasts just before sequential inoculation with to provide an insight into the particular effects they induce at this stage. The grape must of Malvazija istarska was inoculated with monocultures of , , , , and , alongside a control. Eighty volatile compounds were quantified via headspace solid-phase microextraction and gas chromatography-mass spectrometry, and the data were statistically elaborated. Volatile profiles of non- yeasts differed significantly from the control. Most treatments caused increases in linalool and β-damascenone, decreases in higher alcohols and fatty acids, and improved synthesis of odoriferous esters. and produced compounds not commonly found in fermented wines. Multivariate statistical analysis linked the investigated yeasts to specific, particularly abundant compounds. Future studies should explore to what degree these contributions persist after sequential inoculation with in diverse grape must matrices.
PubMed: 36230163
DOI: 10.3390/foods11193088 -
Foods (Basel, Switzerland) Oct 2022Viticulture is one of the traditional industries in Slovakia, where there are six wine-growing regions: Malokarpatska, Southern Slovakia, Central Slovakia, Nitra,...
Viticulture is one of the traditional industries in Slovakia, where there are six wine-growing regions: Malokarpatska, Southern Slovakia, Central Slovakia, Nitra, Eastern Slovakia, and Tokaj. This study focuses on the detection of microbiota in soil samples, grape leaves and berries, and samples taken from fermenting must and young wine (the variety Tramín červený) in relation to the detected concentrations of biogenic amines during the fermentation process. In the examined samples, the number of yeasts and molds (from 3.8 to 6.8 log cfu/g or mL) and TVC (from 3.7 to 6.5 log cfu/g or mL) were determined via culture examination. At the same time, the number of LAB (from ˂3.0 to 4.4 log cfu/g or mL) was determined, which was the highest on day 4 of the must fermentation process and was related to the detected of the highest concentration of biogenic amines (histamine and tyramine) on day 6 in the investigated must samples using the UHPLC system. Mycobiota species were identified by MALDI-TOF MS, PCR, ITS-PCR-RFLP, and PCR sequencing of the amplified products. The study confirmed the presence of the yeasts . At the same time, the presence of molds ( and ) was also confirmed in soil samples, leaves, grape berries, and fresh grape must. The study confirmed the reduction in the species diversity of the microbiota during the must fermentation process, which resulted in decreases in the concentrations of the monitored biogenic amines in the early stages of the must fermentation process and young wine of the variety Tramín červený.
PubMed: 36230137
DOI: 10.3390/foods11193061 -
Microbiology Resource Announcements Nov 2022Torulaspora quercuum is an ascomycete yeast first isolated in 2009. Here, we present the genome sequence of T. quercuum isolate UCD657, which was isolated from soil in...
Torulaspora quercuum is an ascomycete yeast first isolated in 2009. Here, we present the genome sequence of T. quercuum isolate UCD657, which was isolated from soil in Ireland. This genome is 10.4 Mb and was assembled into 8 chromosome-sized scaffolds of >1 Mb in size, plus a mitochondrial genome scaffold.
PubMed: 36214680
DOI: 10.1128/mra.00952-22 -
International Journal of Food... Dec 2022Fungal spoilage limits the shelf life of fermented dairy products. To address the problem, this study explores the potential of lactic acid bacteria as antifungal...
Fungal spoilage limits the shelf life of fermented dairy products. To address the problem, this study explores the potential of lactic acid bacteria as antifungal adjunct cultures in dairy matrices. Strains of lactic acid bacteria (113) representing 19 species were screened for their activity against Penicillium caseifulvum, Aspergillus clavatus and Mucor racemosus in modified MRS medium, milk, and yogurt. Strains of Lactiplantibacillus plantarum, Furfurilactobacillus milii, and Lentilactobacillus parabuchneri inhibited the growth of mycelial fungi. The inhibitory effects of lactic acid bacteria against yeasts were also determined in yogurt with Candida sake, Saccharomyces bayanus, and Torulaspora delbrueckii as challenge strains. The inhibition of yeasts by lactic acid bacteria was strain-specific and unrelated to the activity towards mycelial fungi. Organic acids and hydroxy fatty acids were quantified by liquid chromatograph coupled with refractive index detector and tandem mass spectrometry, respectively. Principal component analysis indicated 10-OH 18: 1 fatty acids and acetate are the main antifungal metabolites and explained over 50 % of the antifungal activity. The correlation analysis of metabolites and mold-free shelf life of milk and yogurt confirmed the role of these compounds. The genomic study analysed genes related to the production of major antifungal metabolites and predicted the formation of 1,2-propanediol and acetate but not of hydroxy unsaturated fatty acids. The findings provide new perspectives on the selection of antifungal strains, the characterization of antifungal metabolites and the exploration of antifungal mechanisms among different species.
Topics: Lactobacillales; Antifungal Agents; Fermentation; Propylene Glycol; Lactobacillaceae; Yeasts; Acetates; Fatty Acids
PubMed: 36202011
DOI: 10.1016/j.ijfoodmicro.2022.109938