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1.
Curr Microbiol ; 81(10): 332, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39198319

RESUMO

Pesticides employed for controlling domestic and agricultural pests are among the most dangerous environmental contaminants. Nevertheless, negligent usage and a lack of technical expertise have led to the contamination and pollution of various ecological niches. The extensive utilization of the organophosphate chlorpyrifos (CPs) for insect infestation control, coupled with its detrimental effects and persistence in the ecosystem, has led to calls for its removal from contaminated sites. The study is mainly focused on degradation of CPs; using viz. Bacillus wiedmannii A3 and Bacillus cereus P14 isolated from tea rhizosphere soil having pesticide contamination in Sonitpur district, Assam, India. These two bacterial strains were able to degrade CPs in vitro within 3 days. Reverse-phase HPLC analysis suggested about 96% reduction of CPs concentration upon bacterial treatment. Again, in case of A3, GC-MS analysis revealed that CPs was modified to 2-hydroxy-3,5,6-trichloropyridine and chlorpyrifos-oxon, thus finally metabolized into non-toxic products. While analyzing P14, silane, dimethyl (2,2,2-trichloroethoxy) propoxy, and 3-aminobenzoic acid, N-trimethylsilyl-, trimethylsilyl ester were identified. These compounds were subsequently transformed into non-toxic products. In addition to this, they demonstrated a significant boost of plant growth-promoting traits in both absence and presence of CPs; also showed growth development in nursery scale condition. Moreover, they functioned as biocontrol agents against Phellinus lamaensis and Colletotrichum gloeosporioides, responsible for brown root rot and anthracnose in North East India tea plantations, respectively. Thus, the pesticide-tolerant Bacilli strains A3 and P14 could be used as bioremediation of contaminated sites and also as biostimulants, and biocontrols in tea crop production.


Assuntos
Bacillus , Biodegradação Ambiental , Clorpirifos , Microbiologia do Solo , Clorpirifos/metabolismo , Bacillus/metabolismo , Bacillus/isolamento & purificação , Índia , Rizosfera , Camellia sinensis/microbiologia , Camellia sinensis/crescimento & desenvolvimento , Poluentes do Solo/metabolismo , Inseticidas/metabolismo , Inseticidas/farmacologia , Chá/microbiologia , Chá/química
2.
Food Chem ; 458: 140174, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38964109

RESUMO

Fu Brick Tea (FBT) is characterized by Fungus Aroma (FA), which determines the quality of FBT products. However, the aroma constituents and their interactive mechanism for FA remain unclear. In this study, the FBT sample with the optimal FA characteristics was selected from 29 FBTs. Then, 19 components with OAV ≥ 1 were identified as the odorants involved in the FA formation. The aroma recombination test suggested that the FA was potentially produced by the synergistic interplay among the 15 key odorants, including (E,E)-2,4-heptadienal, (E,E)-2,4-nonadienal, (E)-2-nonenal, (E,Z)-2,6-nonadienal, (E)-2-octenal, (E)-ß-ionone, 4-ketoisophorone, dihydroactinidiolide, (E)-ß-damascenone, 1-octen-3-ol, linalool, geraniol, heptanal, hexanal, and phenylacetaldehyde. And, the synergistic effects between them were preliminarily studied by aroma omissions, such as modulatory effects, masking effects, compensatory effects, and novelty effects, ultimately contributing to the FA. In all, this work helps us better understand the formation of the FA and provides a basis for the improvement of FBT production technology.


Assuntos
Camellia sinensis , Odorantes , Chá , Compostos Orgânicos Voláteis , Odorantes/análise , Chá/química , Chá/microbiologia , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo , Camellia sinensis/química , Camellia sinensis/microbiologia , Fungos/metabolismo , Fungos/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Aromatizantes/química , Aromatizantes/metabolismo
3.
Food Chem ; 458: 140293, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38970959

RESUMO

The present study aimed to determine microbial community, short-chain fatty acids (SCFAs), and volatilome of Bulang pickled tea during fermentation. Sequencing of 16S rRNA and ITS revealed that Bualng pickled tea was dominated by Lactobacillus plantarum, unclassified Enterobacteriaceae, unclassified Debaryomyces, Candida metapsilosis, Cladosporium sphaerospermum, and unclassified Aspergillus. The overall contents of SCFAs increased, with acetic acid showing the highest content. A total of 398 differential volatile metabolites were detected using differential metabolomics analysis. Out of these different volatile compounds, ten key volatile compounds including (Z)-4-heptenal, 1-(2-thienyl)-ethanone, 5-methyl-(E)-2-hepten-4-one, 2-ethoxy-3-methylpyrazine, p-cresol, 2-methoxy-phenol, ethy-4-methylvalerate, 3-ethyl-phenol, p-menthene-8-thiol, and 2-s-butyl-3-methoxypyrazinewere were screened based on odor activity value (OAV). The Spearman correlation analysis showed a high correlation of SCFAs and volatile compounds with microorganisms, especially L. plantarum and C. sphaerospermum. This study provided a theoretical basis for elucidating the flavor quality formation mechanism of Bulang pickled tea.


Assuntos
Bactérias , Fermentação , Chá , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/análise , Bactérias/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Chá/química , Chá/microbiologia , Chá/metabolismo , Microbiota , Ácidos Graxos Voláteis/metabolismo , Ácidos Graxos Voláteis/análise , Camellia sinensis/metabolismo , Camellia sinensis/química , Camellia sinensis/microbiologia , Fungos/metabolismo , Fungos/classificação , Fungos/genética , Odorantes/análise
4.
J Oral Biosci ; 66(3): 628-632, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39069173

RESUMO

To explore the potential storage and safety of drinking leftover bottled tea beverages from various manufacturers after direct drinking from bottles, we conducted a screening experiment on the growth of salivary bacteria in plastic bottles of tea. The diluted saliva samples from 10 participants were inoculated into the test bottled beverages, which resulted in bacteria, particularly former members of the genus Lactobacillus, growing in some green tea beverages with a neutral pH. In contrast, tea beverages with less bacterial growth contained Streptococcus spp., and the leftovers may be safe to store and drink again.


Assuntos
Saliva , Chá , Chá/microbiologia , Chá/química , Humanos , Saliva/microbiologia , Lactobacillus/isolamento & purificação , Streptococcus/isolamento & purificação , Adulto , Feminino , Concentração de Íons de Hidrogênio
5.
FEMS Microbiol Lett ; 3712024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38866709

RESUMO

Seasonal changes in the diversity of tea plant endophytic fungi and the effects of sample storage conditions on detection were analyzed. Tea leaves were collected from the Saitama Tea Research Institute in Japan during winter (January 2020) and summer (August 2020). The effects of storage temperature (5, 10, 20, 25, and 30°C) and durations (1, 2, 3, 4, 5, 6, and 7 days) on endophytic fungal diversity and community structure were investigated. In summer, storage period and temperature did not affect the fungal colonization rate, frequency, and composition. In winter, storage temperature and period significantly affected the endophytic community structure. Fungal diversity was higher in winter than in summer. Positive relationships between diversity index and storage temperature and period were observed in winter, whereas the opposite trend was observed in summer. Our findings provide insight into the ecology of foliar endophytes of tea plants and the importance of proper sample collection and storage for microbiome studies.


Assuntos
Camellia sinensis , Endófitos , Fungos , Folhas de Planta , Estações do Ano , Temperatura , Endófitos/isolamento & purificação , Endófitos/classificação , Endófitos/genética , Camellia sinensis/microbiologia , Folhas de Planta/microbiologia , Fungos/classificação , Fungos/isolamento & purificação , Fungos/genética , Japão , Biodiversidade , Chá/microbiologia
6.
Food Res Int ; 190: 114568, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38945598

RESUMO

The food industry is increasingly striving to produce probiotics-based food and beverages using sustainable processes. Therefore, the use of by-products in product development has been investigated by several authors. The aim of this work was to investigate the effects of cocoa bean shell infusion in the production of kombucha through microbiological and genetic characterization. Three beverage formulations were prepared, one based on black tea (KBT), one based on cocoa bean shell infusion (KCS) and one containing 50 % black tea and 50 % cocoa shell infusion (KBL). The infusions were prepared with water, filtered, and sucrose was added. They were then homogenized and a portion of finished kombucha and SCOBY (symbiotic culture of bacteria and yeast) were added. Fermentation took place for 13 days and aliquots were collected every three days for physicochemical and microbial count analyses. Samples from the last day of fermentation were sent for DNA sequencing, extraction and quantification. The results were subjected to analysis of variance and compared by using Tukey's test (p < 0.05). The results show that there was a significant decrease in pH over time in all samples, while the titratable acidity increased, indicating an acidification of the beverage due to the production of organic acids. There was an increase in lactic acid bacterial colonies in all the formulations, which have a probiotic nature and are not always found in this type of beverage. Regarding the taxonomic classification of the samples, microorganisms of the kingdoms Fungi and Bacteria, of the families Saccharomycetaceae and Acetobacteraceae, were found in KBT, KCS and KBL, but with different microbiological compositions, with different amounts of yeasts and bacteria. Therefore, the use of by-products such as cocoa bean shell in the production of kombucha can contribute to the reduction of waste in the food industry and, at the same time, accelerate fermentation increasing the presence of lactic acid bacteria when compared to black tea.


Assuntos
Cacau , Fermentação , Microbiologia de Alimentos , Chá de Kombucha , Cacau/microbiologia , Cacau/química , Chá de Kombucha/microbiologia , Chá/microbiologia , Chá/química , Concentração de Íons de Hidrogênio , Manipulação de Alimentos/métodos , Probióticos
7.
Food Chem ; 455: 139864, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38833862

RESUMO

Aspergillus cristatus, the predominant microbe of Fuzhuan brick tea (FBT), is responsible for the creation of distinctive golden flower and unique floral aroma of FBT. The present study examined the alterations in chemical and aromatic components of raw dark tea by solid-state fermentation using A. cristatus (MK346334), the strain isolated from FBT. As results, catechins, total ployphenols, total flavonoids, theaflavins, thearubigins and antioxidant activity were significantly reduced after fermentation. Moreover, 112 and 76 volatile substances were identified by HS-SPME-GC-MS and HS-GC-IMS, respectively, primarily composed of alcohols, ketones, esters and aldehydes. Furthermore, the calculation of odor activity values revealed that 19 volatile chemicals, including hexanal, heptanal, linalool and methyl salicylate, were the main contributors to the floral, fungal, woody and minty aroma of dark tea. The present research highlights the pivotal role played by the fermentation with A. cristatus in the chemical composition, antioxidant property and distinctive flavor of dark tea.


Assuntos
Aspergillus , Camellia sinensis , Nariz Eletrônico , Fermentação , Cromatografia Gasosa-Espectrometria de Massas , Odorantes , Microextração em Fase Sólida , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo , Aspergillus/metabolismo , Aspergillus/química , Odorantes/análise , Camellia sinensis/química , Camellia sinensis/metabolismo , Camellia sinensis/microbiologia , Paladar , Aromatizantes/química , Aromatizantes/metabolismo , Chá/química , Chá/metabolismo , Chá/microbiologia , Antioxidantes/metabolismo , Antioxidantes/química
8.
Food Chem ; 455: 139932, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38843719

RESUMO

White tea stored for various times have different flavors. However, the mechanism of flavor conversion remains elusive. Flavonoids and amino acids are two typical flavor components in tea. Herein, the contents of 46 flavonoids and 40 amino acids were measured in white tea (Shoumei) stored for 1, 3, 5 and 7 years, respectively. L-tryptophan, L-ornithine and L-theanine contribute to the refreshing taste of Shoumei 1 and 3. Quercetin, rutin and hesperidin contribute to aging charm and grain aroma of Shoumei 5 and 7. 306 bacterial OTUs and 268 fungal OTUs core microbiota existed in all samples. Interestingly, white teas contained higher richness of fungi than bacteria. The correlation analysis showed that the cooperation with bacteria and fungi may result in the flavonoids and amino acids composition changes in white teas during storage. Overall, this study provides new insights into flavor conversion of white tea during storage.


Assuntos
Aminoácidos , Bactérias , Camellia sinensis , Flavonoides , Armazenamento de Alimentos , Fungos , Chá , Aminoácidos/análise , Aminoácidos/metabolismo , Chá/química , Chá/microbiologia , Bactérias/metabolismo , Bactérias/isolamento & purificação , Bactérias/classificação , Flavonoides/análise , Fungos/metabolismo , Camellia sinensis/química , Camellia sinensis/microbiologia , Paladar , Aromatizantes/química , Aromatizantes/metabolismo , Aromatizantes/análise , Microbiota
9.
Sci Rep ; 14(1): 11295, 2024 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760401

RESUMO

Intercropping with Pleurotus ostreatus has been demonstrated to increase the tea yield and alleviate soil acidification in tea gardens. However, the underlying mechanisms remain elusive. Here, high-throughput sequencing and Biolog Eco analysis were performed to identify changes in the community structure and abundance of soil microorganisms in the P. ostreatus intercropped tea garden at different seasons (April and September). The results showed that the soil microbial diversity of rhizosphere decreased in April, while rhizosphere and non-rhizosphere soil microbial diversity increased in September in the P. ostreatus intercropped tea garden. The diversity of tea tree root microorganisms increased in both periods. In addition, the number of fungi associated with organic matter decomposition and nutrient cycling, such as Penicillium, Trichoderma, and Trechispora, was significantly higher in the intercropped group than in the control group. Intercropping with P. ostreatus increased the levels of total nitrogen (TN), total phosphorus (TP), and available phosphorus (AP) in the soil. It also improved the content of secondary metabolites, such as tea catechins, and polysaccharides in tea buds. Microbial network analysis showed that Unclassified_o__Helotiales, and Devosia were positively correlated with soil TN and pH, while Lactobacillus, Acidothermus, and Monascus were positively correlated with flavone, AE, and catechins in tea trees. In conclusion, intercropping with P. ostreatus can improve the physical and chemical properties of soil and the composition and structure of microbial communities in tea gardens, which has significant potential for application in monoculture tea gardens with acidic soils.


Assuntos
Microbiota , Raízes de Plantas , Pleurotus , Rizosfera , Microbiologia do Solo , Solo , Chá , Pleurotus/crescimento & desenvolvimento , Pleurotus/metabolismo , Raízes de Plantas/microbiologia , Chá/microbiologia , Solo/química , Camellia sinensis/microbiologia , Nitrogênio/metabolismo , Nitrogênio/análise , Fósforo/análise , Fósforo/metabolismo , Fungos/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Concentração de Íons de Hidrogênio
10.
Food Res Int ; 186: 114401, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38729704

RESUMO

Fuzhuan brick tea (FBT) fungal fermentation is a key factor in achieving its unique dark color, aroma, and taste. Therefore, it is essential to develop a rapid and reliable method that could assess its quality during FBT fermentation process. This study focused on using electronic nose (e-nose) and spectroscopy combination with sensory evaluations and physicochemical measurements for building machine learning (ML) models of FBT. The results showed that the fused data achieved 100 % accuracy in classifying the FBT fermentation process. The SPA-MLR method was the best prediction model for FBT quality (R2 = 0.95, RMSEP = 0.07, RPD = 4.23), and the fermentation process was visualized. Where, it was effectively detecting the degree of fermentation relationship with the quality characteristics. In conclusion, the current study's novelty comes from the established real-time method that could sensitively detect the unique post-fermentation quality components based on the integration of spectral, and e-nose and ML approaches.


Assuntos
Nariz Eletrônico , Fermentação , Espectroscopia de Luz Próxima ao Infravermelho , Paladar , Chá , Chá/química , Chá/microbiologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Odorantes/análise , Quimiometria/métodos , Humanos , Fungos/metabolismo , Aprendizado de Máquina , Compostos Orgânicos Voláteis/análise
11.
Food Chem ; 454: 139658, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38810451

RESUMO

The distinct quality of Qingzhuan tea is greatly influenced by the bacterial community but was poorly characterized. Therefore, this study investigated the Co-occurrence network and functional profiling of the bacterial community, with special attention paid to core functional bacteria in the industrial pile fermentation. Microbiomics analysis indicated that Klebsiella and Pantoea dominated raw tea leaves, and were rapidly replaced by Pseudomonas in pile fermentation, but substituted mainly by Burkholderia and Saccharopolyspora in final fermented tea. Bacterial taxa were grouped into 7 modules with the dominant in module I, III, and IV, which were involved in flavor formation and biocontrol production. Functional profiling revealed that "penicillin and cephalosporin biosynthesis" increased in pile fermentation. Twelve bacterial genera were identified as core functional bacteria, in which Klebsiella, Pantoea, and Pseudomonas also dominated the pile fermentation. This work would provide theoretical basis for its chemical biofortification and quality improvement by controlling bacterial communities.


Assuntos
Bactérias , Camellia sinensis , Fermentação , Chá , Bactérias/metabolismo , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/genética , Camellia sinensis/microbiologia , Camellia sinensis/metabolismo , Camellia sinensis/química , Chá/microbiologia , Chá/química , Chá/metabolismo , Microbiota , Folhas de Planta/microbiologia , Folhas de Planta/química , Folhas de Planta/metabolismo
12.
Genes (Basel) ; 15(5)2024 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-38790239

RESUMO

Fertilization is an essential aspect of tea plantation management that supports a sustainable tea production and drastically influences soil microbial communities. However, few research studies have focused on the differences of microbial communities and the variation in tea quality in response to different fertilization treatments. In this work, the soil fertility, tea quality, and soil microbial communities were investigated in two domestic tea plantations following the application of chemical and organic fertilizers. We determined the content of mineral elements in the soil, including nitrogen, phosphorus, and potassium, and found that the supplementation of chemical fertilizer directly increased the content of mineral elements. However, the application of organic fertilizer significantly improved the accumulation of tea polyphenols and reduced the content of caffeine. Furthermore, amplicon sequencing results showed that the different ways of applying fertilizer have limited effect on the alpha diversity of the microbial community in the soil while the beta diversity was remarkably influenced. This work also suggests that the bacterial community structure and abundance were also relatively constant while the fungal community structure and abundance were dramatically influenced; for example, Chaetomiaceae at the family level, Hypocreaceae at the order level, Trichoderma at the genus level, and Fusarium oxysporum at the species level were predominantly enriched in the tea plantation applying organic fertilizer. Moreover, the bacterial and fungal biomarkers were also analyzed and it was found that Proteobacteria and Gammaproteobacteria (bacteria) and Tremellomycetes (fungi) were potentially characterized as biomarkers in the plantation under organic fertilization. These results provide a valuable basis for the application of organic fertilizer to improve the soil of tea plantations in the future.


Assuntos
Camellia sinensis , Fertilizantes , Microbiota , Microbiologia do Solo , Chá , Fertilizantes/análise , Chá/microbiologia , Camellia sinensis/microbiologia , Camellia sinensis/genética , Solo/química , Bactérias/genética , Bactérias/classificação , Nitrogênio/metabolismo , Nitrogênio/análise , Fósforo/análise , Fósforo/metabolismo , Fungos/genética , Fungos/classificação
13.
Arch Microbiol ; 206(5): 239, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38689148

RESUMO

Camellia sinensis is an important economic plant grown in southern subtropical hilly areas, especially in China, mainly for the production of tea. Soil acidification is a significant cause of the reduction of yield and quality and continuous cropping obstacles in tea plants. Therefore, chemical and microbial properties of tea growing soils were investigated and phenolic acid-degrading bacteria were isolated from a tea plantation. Chemical and ICP-AES investigations showed that the soils tested were acidic, with pH values of 4.05-5.08, and the pH negatively correlated with K (p < 0.01), Al (p < 0.05), Fe and P. Aluminum was the highest (47-584 mg/kg) nonessential element. Based on high-throughput sequencing, a total of 34 phyla and 583 genera were identified in tea plantation soils. Proteobacteria and Acidobacteria were the main dominant phyla and the highest abundance of Acidobacteria was found in three soils, with nearly 22% for the genus Gp2. Based on the functional abundance values, general function predicts the highest abundance, while the abundance of amino acids and carbon transport and metabolism were higher in soils with pH less than 5. According to Biolog Eco Plate™ assay, the soil microorganisms utilized amino acids well, followed by polymers and phenolic acids. Three strains with good phenolic acid degradation rates were obtained, and they were identified as Bacillus thuringiensis B1, Bacillus amyloliquefaciens B2 and Bacillus subtilis B3, respectively. The three strains significantly relieved the inhibition of peanut germination and growth by ferulic acid, p-coumaric acid, p-hydroxybenzoic acid, cinnamic acid, and mixed acids. Combination of the three isolates showed reduced relief of the four phenolic acids due to the antagonist of B2 against B1 and B3. The three phenolic acid degradation strains isolated from acidic soils display potential in improving the acidification and imbalance in soils of C. sinensis.


Assuntos
Camellia sinensis , Hidroxibenzoatos , Microbiologia do Solo , Solo , Hidroxibenzoatos/metabolismo , Solo/química , Concentração de Íons de Hidrogênio , Camellia sinensis/microbiologia , Camellia sinensis/metabolismo , China , Bactérias/classificação , Bactérias/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/efeitos dos fármacos , Chá/microbiologia , Chá/química , Acidobacteria/metabolismo , Acidobacteria/genética , Acidobacteria/isolamento & purificação
14.
Food Chem ; 450: 139376, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-38648695

RESUMO

Wuyi Rock Tea (WRT) has different characteristics of "rock flavor" due to different production areas. In this study, we investigated the flavor characteristics and key components of "rock flavor" and the influence of microorganisms on the substances by combining metabolomics and microbiomics with the Rougui WRTs from the Zhengyan, Banyan, and Waishan production areas. The results showed that Rougui has a strong floral and fruity aroma, which is mainly brought by hotrienol, and the sweet, smooth, and fresh taste is composed of epicatechin gallate, epigallocatechin, epigallocatechin gallate, caffeine, theanine, soluble sugar, and sweet and bitter amino acids. Bacteria Chryseobacterium, Pedobacter, Bosea, Agrobacterium, Stenotrophomonas, and Actinoplanes mainly influence the production of hotrienol, epicatechin gallate, and theanine. Fungi Pestalotiopsis, Fusarium, Elsinoe, Teichospora and Tetracladium mainly influence the production of non-volatile compounds. This study provides a reference for the biological formation mechanism of the characteristic aroma of WRT's "rock falvor".


Assuntos
Bactérias , Camellia sinensis , Aromatizantes , Fungos , Metabolômica , Paladar , Chá , Bactérias/metabolismo , Bactérias/classificação , Bactérias/isolamento & purificação , Aromatizantes/metabolismo , Aromatizantes/química , Chá/química , Chá/microbiologia , Camellia sinensis/química , Camellia sinensis/metabolismo , Camellia sinensis/microbiologia , Fungos/metabolismo , Odorantes/análise , Humanos
15.
Food Chem ; 451: 139452, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38688098

RESUMO

Golden-flower fungus (Eurotiwm Cristatum, EC) is widely inoculated in dark tea to endow a typical fungal floral aroma. Recently, Golden Flower White Tea (GFWT), prepared by transplanting EC-mediated fermentation to white tea (Shoumei, SM) to reform the roughness and coarseness, has attracted much attention attributed to coordinated flavor. However, the bio-chemistry reactions between EC and SM, along with origination of composited aroma are still unclear. Thus, the rejected EC, GFWT leaves and stems after EC removal were separated by layer-by-layer stripping following sensory evaluation, volatiles and microstructure analysis to uncover aroma formation mechanism. In GFWT, EC presents fungal flower aroma rather than contribution of extracellular enzymes secreted by fungus in Fu brick tea. Moreover, the short "flowering process" (7 days) endows SM with a stale, jujube, and sweet aroma, which is regarded as the typical characteristic of aged white tea. This inspires EC-mediated fermentation as a promising rapid aging process.


Assuntos
Camellia sinensis , Fermentação , Odorantes , Paladar , Compostos Orgânicos Voláteis , Odorantes/análise , Camellia sinensis/química , Camellia sinensis/microbiologia , Camellia sinensis/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/análise , Humanos , Chá/química , Chá/microbiologia , Aromatizantes/química , Aromatizantes/metabolismo , Folhas de Planta/química , Folhas de Planta/microbiologia , Folhas de Planta/metabolismo
16.
Food Res Int ; 178: 113979, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38309920

RESUMO

The distinct sensory quality of Qingzhuan tea is mainly formed in pile fermentation by a group of functional microorganisms but the core functional ones was poorly characterized. Therefore, this study investigated the dynamic changes in the fungal community and metabolic profile by integrating microbiomics and metabolomics, and explored the core functional fungi driving the metabolic conversion in the industrial pile fermentation of Qingzhuan tea. Indicated by microbiomics analysis, Aspergillus dominated the entire pile-fermentation process, while Thermoascus, Rasamsonia, and Cylindrium successively abounded in the different stages of the pile fermentation. A total of 50 differentially changed metabolites were identified, with the hydrolysis of galloyl/polymeric catechins, biosynthesis of theabrownins, oxidation of catechins, N-ethyl-2-pyrrolidinone substitution of catechins, and deglycosylation of flavonoid glucosides. Nine fungal genera were identified as core functional fungi, in which Aspergillus linked to the hydrolysis of polymeric catechins and insoluble polysaccharides as well as biosynthesis of theabrownins, while Thermoascus participated in the biosynthesis of theabrownins, deglycosylation of flavonoid glucosides, and N-ethyl-2-pyrrolidinone substitution of catechins. These findings would advance our understanding of the quality formation of Qingzhuan tea and provide a benchmark for precise inoculation for its quality improvement.


Assuntos
Catequina , Chá , Chá/microbiologia , Fermentação , Flavonoides/metabolismo , Catequina/análise , Aspergillus/metabolismo , Glucosídeos
17.
Sci Rep ; 13(1): 9367, 2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37296164

RESUMO

A kombucha is a tea and sugar fermented by over sixty kinds of yeasts and bacteria. This symbiotic community produces kombucha mats, which are cellulose-based hydrogels. The kombucha mats can be used as an alternative to animal leather in industry and fashion once they have been dried and cured. Prior to this study, we demonstrated that living kombucha mats display dynamic electrical activity and distinct stimulating responses. For use in organic textiles, cured mats of kombucha are inert. To make kombucha wearables functional, it is necessary to incorporate electrical circuits. We demonstrate that creating electrical conductors on kombucha mats is possible. After repeated bending and stretching, the circuits maintain their functionality. In addition, the abilities and electronic properties of the proposed kombucha, such as being lighter, less expensive, and more flexible than conventional electronic systems, pave the way for their use in a diverse range of applications.


Assuntos
Bactérias , Leveduras , Animais , Fermentação , Chá/microbiologia
18.
Int J Food Microbiol ; 385: 110015, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36403330

RESUMO

Despite tea beneficial health effects, there is a substantial risk of tea contamination by harmful pathogens and mycotoxins. A total of 40 tea samples (17 green (raw) tea; 13 black (fermented) tea; 10 herbal infusions or white tea) were purchased from different markets located in Lisbon district during 2020. All products were directly available to consumers either in bulk (13) and or in individual packages (27). Bacterial analysis was performed by inoculating 150 µL of samples extracts in tryptic soy agar (TSA) supplemented with 0.2 % nystatin medium for mesophilic bacteria, and in Violet Red bile agar (VRBA) medium for coliforms (Gram-negative bacteria). Fungal research was performed by spreading 150 µL of samples in malt extract agar (MEA) supplemented with 0.05 % chloramphenicol and in dichloran-glycerol agar (DG18) media. The molecular detection of the Aspergillus sections Fumigati, Nidulantes, Circumdati and Flavi was carried out by Real Time PCR (qPCR). Detection of mycotoxins was performed using high performance liquid chromatograph (HPLC) with a mass spectrometry detector. Azole resistance screening was achieved following the EUCAST guidelines. The highest counts of total bacteria (TSA) were obtained in green raw tea (81.6 %), while for coliform counts (VRBA) were found in samples from black raw tea (96.2 %). The highest fungal counts were obtained in green raw tea (87.7 % MEA; 69.6 % DG18). Aspergillus sp. was the most prevalent genus in all samples on MEA (54.3 %) and on DG18 (56.2 %). In the raw tea 23 of the samples (57.5 %) presented contamination by one to five mycotoxins in the same sample. One Aspergillus section Fumigati isolate from green tea beverage recovered form itraconazole-Sabouraud dextrose agar (SDA) medium, presented itraconazole and posaconazole E-test MICs above MIC90 values. Our findings open further discussion regarding the One-Health approach and the necessary investment in researching biological hazards and azole-resistance associated with the production and consumption of tea (in particular green tea).


Assuntos
Camellia sinensis , Micotoxinas , Saúde Única , Ágar , Aspergillus , Azóis , Bactérias , Meios de Cultura/análise , Itraconazol/análise , Micotoxinas/análise , Chá/microbiologia
19.
Nutrients ; 14(24)2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36558393

RESUMO

The Western diet can negatively affect the gut microbiota and is associated with metabolic disorders. Kombucha, a tea fermented by a symbiotic culture of bacteria and yeast (SCOBY), is known for its bioactive properties and has become popular in the last years. In this study, we evaluated the effects of regular kombucha consumption on the gut microbiota and on outcomes related to the intestinal health of Wistar rats fed a high-fat high-fructose diet. After eight weeks receiving a standard diet (AIN-93M) (n = 10) or a high-fat and high-fructose diet (HFHF) (n = 30) to induce metabolic disorders, the animals were subdivided into four groups: AIN-93M (n = 10); HFHF (n = 10); GTK (HFHF + green tea kombucha (n = 10); and BTK (HFHF + black tea kombucha; n = 10) for 10 weeks. Although body composition did not differ among the groups, the HFHF diet was associated with metabolic alterations, and stimulated the growth of gram-negative bacteria such as Proteobacteria and Bacteroides. Kombucha ingestion could somewhat modulate the gut microbiota, attenuating the effects of a Western diet by increasing propionate production and favoring the growth of beneficial bacteria, such as Adlercreutzia in the GTK group. Our results suggest that regular kombucha consumption may be beneficial to intestinal health, which can be mostly attributed to its high content and diversity of phenolic compounds.


Assuntos
Camellia sinensis , Microbioma Gastrointestinal , Ratos , Animais , Chá/microbiologia , Ratos Wistar , Frutose/farmacologia , Polifenóis/farmacologia , Dieta Hiperlipídica/efeitos adversos
20.
Vopr Pitan ; 91(4): 115-120, 2022.
Artigo em Russo | MEDLINE | ID: mdl-36136953

RESUMO

Kombucha is a beverage made by fermenting sweetened brewed tea (substrate) by symbiotic culture of yeast and bacteria. Numerous researches on optimization of fermentation process, determination of the influence of technological factors on physical and chemical properties, formation of taste and flavor profile of the beverages, prevention of industrial product risks are due to the growing popularity of kombucha in Europe and the USA. Technological features of kombucha production are to optimize conditions for the growth of symbiotic culture and substrate fermentation. The duration of the process depends on the composition of the substrate, the ratio of tea mushroom and substrate, temperature, size and shape of fermentation vessel. The aim of the work was to generalize the results of studying the technological features of the production of fermented kombucha type beverages and to identify the factors that affect the chemical composition and safety of the finished beverages. Material and methods. Analytical research was carried out on the main databases for the keyword "kombucha". The criteria for inclusion of articles in the analysis were research articles with open access and presenting detailed technology of kombucha. Results. The technology of kombucha production is based on fermentation of the substrate and obtaining the base of the beverage with high content of organic acids, mainly acetic acid. In order to ensure microbiological safety the acetic acid concentration in the beverage base must be at least 1.2%. The high organic acid content necessitates the use of only glass or stainless steel fermentation equipment approved for food contact. The fermentation temperature ranges from 18 to 32 °C. The fermentation process is monitored according to basic criteria: temperature, pH value, acidity, acetic acid content, ethyl alcohol content, and residual sugar content. Kombucha production process is connected with microbiological, chemical and physical risks which could appear in case of using low quality raw materials, equipment and consumer packaging made of materials which do not correspond to sanitary norms, violating technological regimes, storage conditions of raw materials and ready production. To prevent hazards affecting the quality and safety of the finished product, it is necessary to control the technological process at all stages of production. Conclusion. Following sanitary-hygienic norms and technological regimes allows producing kombucha with a balanced taste and aroma, which meets the safety requirements for fermented beverages.


Assuntos
Bebidas Fermentadas , Chá , Ácido Acético/análise , Bebidas/análise , Bebidas/microbiologia , Etanol/análise , Fermentação , Aço Inoxidável , Açúcares , Chá/microbiologia , Tecnologia
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