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Foods (Basel, Switzerland) Apr 2023Pellicle formation is the most typical characteristic of deteriorating fermented vegetable products. essential oil (PEO) is widely used as a useful natural...
Pellicle formation is the most typical characteristic of deteriorating fermented vegetable products. essential oil (PEO) is widely used as a useful natural preservative. However, few studies have addressed the antifungal activity and mechanism of PEO in pellicle formation microorganisms, and it is still unclear whether it can inhibit pellicle formation and affect its volatile compounds in Sichuan pickles. The current study showed that PEO can inhibit pellicle formation during fermentation of Sichuan pickles as it had significant antifungal activity against the pellicle formation microorganisms SH1 and SH2. The minimum inhibitory concentration (MIC) of PEO against SH1 and SH2 was determined to be 0.4 μL/mL, and the minimum fungicidal concentrations (MFCs) were 1.6 μL/mL and 0.8 μL/mL, respectively. The antifungal mechanism was activated as a result of damage to the cell membrane, an increase in the cell permeability, a decrease in the mitochondrial membrane potential, and the inhibition of ATPase activity. Meanwhile, the addition of PEO to Sichuan pickles can enrich the profiles of volatile compounds during fermentation, including limonene, myrcene, 1,8-cineole, linalool, perilla ketone, heptanal, hexanal, α-thujone and β-terpineol and thus improve the overall sensory acceptability. These results indicated that PEO has the potential to be used as a novel food preservative to control pellicle formation in fermented vegetables.
PubMed: 37107388
DOI: 10.3390/foods12081593 -
Current Research in Food Science 2023Wheat-gluten, the protein-rich portion of wheat, can be processed to produce a highly savory sauce product after solid and liquid-state fermentation (SSF and LSF) with...
Wheat-gluten, the protein-rich portion of wheat, can be processed to produce a highly savory sauce product after solid and liquid-state fermentation (SSF and LSF) with the inoculation of selected lactic acid bacteria (LAB) and yeast under salt-free condition. However, limited research has been done on the impact of different types of microbes in this process. This work studied the flavour impact on fermented wheat-gluten by the single inoculation of or one yeast ( or ). Glucose was depleted during LSF in all treatments. Lactic acid production increased over time in -fermented samples but not in yeast-fermented samples. Cysteine, serine and arginine remained low over LSF in -fermented samples but increased in yeast-fermented samples. More fruity esters such as isoamyl acetate and isobutyl acetate were detected in samples fermented by , while boosted the production of alcohols such as 3-methyl butanol and 2-phenylethyl alcohol. Principal component analysis revealed a clear difference in volatile profiles of the samples fermented with different strains. Therefore, the fermented sauce can potentially be processed into different flavor directions, and based on the flavor profile, be used in different food applications.
PubMed: 37033740
DOI: 10.1016/j.crfs.2023.100492 -
Journal of Economic Entomology Apr 2023Carpophilus davidsoni (Dobson) is an important pest of Australian stone fruit. Current management practices for this beetle include the use of a trap that contains an...
Carpophilus davidsoni (Dobson) is an important pest of Australian stone fruit. Current management practices for this beetle include the use of a trap that contains an attractant lure comprised of aggregation pheromones and a 'co-attractant' mixture of volatiles from fruit juice fermented using Baker's yeast, Saccharomyces cerevisiae (Hansen). We explored whether volatiles from yeasts Pichia kluyveri (Bedford) and Hanseniaspora guilliermondii (Pijper), which are closely associated with C. davidsoni in nature, might improve the effectiveness of the co-attractant. Field trials using live yeast cultures revealed that P. kluyveri trapped higher numbers of C. davidsoni compared to H. guilliermondii, and comparative GC-MS of volatile emissions of the two yeasts led to the selection of isoamyl acetate and 2-phenylethyl acetate for further investigation. In subsequent field trials, trap catches of C. davidsoni were significantly increased when 2-phenylethyl acetate was added to the co-attractant, compared to when isoamyl acetate was added, or both isoamyl acetate and 2-phenylethyl acetate. We also tested different concentrations of ethyl acetate in the co-attractant (the only ester in the original lure) and found contrasting results in cage bioassays and field trails. Our study demonstrates how exploring volatile emissions from microbes that are ecologically associated with insect pests can result in more potent lures for use in integrated pest management strategies. Results from laboratory bioassays screening volatile compounds should be treated with caution when making inferences regarding attraction under field conditions.
Topics: Animals; Coleoptera; Fruit; Australia; Yeasts; Pheromones
PubMed: 36881679
DOI: 10.1093/jee/toad027 -
Moscow University Biological Sciences... 2022The taxonomic composition and spatial localization of yeast and bacteria in kefir grains (KG) obtained for study from different regions of the planet were investigated....
The taxonomic composition and spatial localization of yeast and bacteria in kefir grains (KG) obtained for study from different regions of the planet were investigated. The diversity of their microbiome has been demonstrated by high-throughput sequencing of bacterial 16S rRNA genes and the ITS1 region of the 18S-ITS1-5.8S-ITS2-28S complex of yeast rRNA. It has been established that the main representatives of the complex community of KG from different regions are lactic acid bacteria (LAB; lactobacilli, lactococci, and spp. in different ratios) and different types of yeast of the genus (family ). Acetic acid bacteria and a small percentage of yeast were detected in the KG from Tibet, and yeast was detected in the KG from Ossetia.
PubMed: 36843649
DOI: 10.3103/S0096392522040010 -
Journal of Food Science Mar 2023Despite many non-Saccharomyces yeasts being considered spoilage microorganisms, they can increase aroma and flavor diversity in alcoholic beverages. The purpose of this...
Despite many non-Saccharomyces yeasts being considered spoilage microorganisms, they can increase aroma and flavor diversity in alcoholic beverages. The purpose of this study was to investigate nontraditional inoculation strategies using aroma-producing yeast strains for Kyoho wine fermentation, followed by an instrumental analysis and sensory evaluation. The winemaking process was carried out using Saccharomyces cerevisiae Gr112, Hanseniaspora uvarum Pi235, and Pichia kluyveri Pe114. Multiple inoculation strategies were explored. In instrumental analysis results, mixed culture could promote the formation of esters (5.9-folds) and glycerol (1.3-folds) and reduce the content of ethanol (-0.5% [v/v]) in wine. The sensory analysis results suggested that the three yeast strains sequential inoculation treatment was associated with the aroma attributes "floral," "red fruity," and "tropical fruity." Co-cultivation contributed to an increase in complexity and aromatic intensity, with the three-strain inoculation treatment presenting a more distinctive appearance. PRACTICAL APPLICATION: The inoculation of S. cerevisiae improved the accumulation of volatile acids and esters by inhibiting the growth of non-Saccharomyces yeast strains. Inoculation of H. uvarum and P. kluyveri would effectively solve the defect of excessive content of higher alcohols in wines produced by S. cerevisiae. The suitable inoculation strategy between non-Saccharomyces yeasts could improve the overall quality of Kyoho wine whose starter might be widely used in fermentation industry.
Topics: Wine; Saccharomyces cerevisiae; Odorants; Yeast, Dried; Fermentation; Ethanol
PubMed: 36660881
DOI: 10.1111/1750-3841.16468 -
Journal of Food Science Dec 2022This study examined the influence of pectinase-producing non-Saccharomyces yeasts on the chemical and sensory attributes of red and white wines with added pectin. Merlot...
This study examined the influence of pectinase-producing non-Saccharomyces yeasts on the chemical and sensory attributes of red and white wines with added pectin. Merlot and Chardonnay wines were produced with or without a mixture of pectinase-producing non-Saccharomyces yeasts (Cryptococcus adeliensis, Issatchenkia orientalis, and Pichia kluyveri) added to the must prior to alcoholic fermentation conducted by a commercial strain of Saccharomyces cerevisiae. To ensure sufficient substrate was present, varying concentrations of apple pectin (up to 1.25 g/L for red wines and 1.00 g/L for white wine) were added at the start of fermentation. After bottling, trained panelists (n = 10) analyzed these wines for aroma, flavor, taste, and mouthfeel attributes. For both wines, significant interactions were noted between the presence of non-Saccharomyces yeasts and pectin addition which affected pH, titratable acidity, and concentrations of D-galacturonic acid. While no significant sensory differences were observed among the red wines, limited changes were noted for white wines. However, a strong positive correlation was found between the D-galacturonic acid and buttery aroma for Chardonnay and with flavor for Merlot. Increasing D-galacturonic acid concentrations, through utilization of non-Saccharomyces yeasts, may improve the wine quality as a buttery aroma is often associated with high-quality Chardonnay. For both red and white wines, the utilization of these particular non-Saccharomyces yeasts significantly influenced chemical properties but yielded minor sensory changes without any faults. PRACTICAL APPLICATION: With the recent trend to reduce alcohol content in commercial wines, the interest in non-Saccharomyces yeasts has grown. This study showed that the addition of non-Saccharomyces yeasts, perhaps due to their pectinase activity, influenced the chemical characteristics of red and white wines with limited sensory differences, making these yeasts a useful tool for winemakers to modify wine properties.
Topics: Wine; Polygalacturonase; Ethanol; Yeasts; Fermentation; Saccharomyces cerevisiae; Pectins; Vitis
PubMed: 36357987
DOI: 10.1111/1750-3841.16371 -
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 -
Pest Management Science Jan 2023Host plant-microbe associations mediate interspecific interactions amongst herbivorous insects. However, this theory has rarely been ecologically verified in tephritid...
BACKGROUND
Host plant-microbe associations mediate interspecific interactions amongst herbivorous insects. However, this theory has rarely been ecologically verified in tephritid fruit flies. Research on this subject can not only help predict tephritid species invasion and occurrence patterns, but also develop potential novel lures for the control of the tephritid fruit fly pests. Recently, we observed mixed infestation of Bactrocera minax and Bactrocera dorsalis larvae in citrus orchards, which prompted us to explore the underlying mechanism.
RESULTS
Following oviposition by B. minax, the yeast Pichia kluyveri translocated to and proliferated inside the citrus fruit. The level of d-limonene released from citrus fruits containing P. kluyveri was 27 times higher than that released from healthy fruits. Mature B. dorsalis females were attracted to d-limonene and oviposited into fruits previously infested by B. minax. Furthermore, the interspecific interaction between B. dorsalis and B. minax within the same fruit significantly decreased the number of surviving larvae and pupal weight in B. dorsalis, but its effect on B. minax was weaker.
CONCLUSION
In the studied interspecific interaction, B. minax occupies the dominant position, implying ecological significance for this species in terms of consolidating its own niche and inhibiting the invasion of exotic species. To our best knowledge, this is the first report from both ecological and physiological perspectives on a symbiotic yeast mediating the interaction between B. minax and B. dorsalis through altering fruit volatiles. © 2022 Society of Chemical Industry.
Topics: Saccharomyces cerevisiae
PubMed: 36177948
DOI: 10.1002/ps.7211 -
New Microbes and New Infections 2022
PubMed: 36177393
DOI: 10.1016/j.nmni.2022.101018