Degradation of Cell Wall Polysaccharides during Traditional and Tank Fermentation of Chinese Liupao Tea.

The increase of polysaccharides in the dark tea pile process is thought to be connected to the cell wall polysaccharides' breakdown. However, the relationship between tea polysaccharides (TPSs) and tea cell wall polysaccharides has not been further explored. In this study, the structural changes in the cell wall polysaccharides [e.

Deciphering the underlying core microorganisms and the marker compounds of Liupao tea during the pile-fermentation process.

Background: Pile fermentation is one of the key steps in developing the Liupao tea (LBT) quality and unique characteristics. The complex biochemical profile of LBT results from microorganisms present during the pile-fermentation process. However, the critical underlying microorganisms and the marker compounds still need to be determined.

Isolation, identification, and community diversity of microorganisms during tank fermentation of Liupao tea.

Tank fermentation is a novel approach to fermenting teas; however, the species of microorganisms present remain unclear. The microbial community composition of Liupao tea at various stages of tank fermentation was analyzed using high-throughput sequencing. Sphingomonas, Aquabacterium, Pelomonas, Acinetobacter, Blastobotrys, Aspergillus, Debaryomyces, and Aureobasidium were the predominant genera, which is different from pile fermentation.

Structural Characterization and In Vitro Antioxidant, Hypoglycemic and Hypolipemic Activities of a Natural Polysaccharide from Liupao Tea.

This study extracted and purified a natural polysaccharide (TPS-5) that has a molecular weight of 48.289 kDa from Liupao tea, a typical dark tea with many benefits to human health. TPS-5 was characterized as a pectin-type acidic polysaccharide.

Determination of the variations in the metabolic profile and sensory quality of Liupao tea during fermentation through UHPLC-HR-MS metabolomics.

Liupao tea is a dark tea with unique quality. Semi-finished Liupao tea with two different fermentation processes (traditional/tank) was analyzed to explain the chemical characteristics and taste quality. The content change rate of polyphenols, flavonoids, and theabrownin in traditional fermentation was approximately twice that in tank fermentation.

Screening strategy for predominant phenolic components of digestive enzyme inhibitors in passion fruit peel extracts on simulated gastrointestinal digestion.

Background: The targeted biological activity of a natural product is often the result of the combined action of multiple functional components. Screening for predominant contributing components of targeting activity is crucial for quality evaluation.

Results: Thirteen and nine phenolic compounds inhibiting α-glucosidase and α-amylase, respectively, were identified in the ethanol extracts of passion fruit peel through liquid chromatography-tandem mass spectrometry and multivariate analysis.

Two Polysaccharides from Liupao Tea Exert Beneficial Effects in Simulated Digestion and Fermentation Model In Vitro.

Liupao tea is an important dark tea, but few studies on purified Liupao tea polysaccharide (TPS) are reported in the literature. In this study, two TPSs, named TPS2 and TPS5, with molecular weights of 70.5 and 133.

Expression of citrinin biosynthesis gene in Liupao tea and effect of Penicillium citrinum on tea quality.

Similar to Pu-erh tea, Liupao tea is a post-fermented tea that is produced through natural fermentation by microorganisms. Penicillium citrinum is involved in multiple production processes of Liupao tea that can produce citrinin, a secondary metabolite with renal toxicity; however, the effect of P. citrinum on the quality of Liupao tea has not been investigated yet.

Antihyperlipidemic effect and increased antioxidant enzyme levels of aqueous extracts from Liupao tea and green tea in vivo.

Liupao tea (fermented dark tea) may improve the active function of hyperlipidemia. Utilizing a hyperlipidemia Sprague-Dawley model and UPLC-MS/MS metabolomics, we examined how the effect of Liupao and green tea extracts on hyperlipidemia and antoxidant enzyme levels and compared their constituents. The results showed that the two types of tea could reduce the levels of total cholesterol (TC), total triglyceride, and low-density lipoprotein cholesterol (LDL-C); increase the contents of bile acids and cholesterol in feces; and improve catalase and glutathione peroxidase (GSH-Px) activities.

Development and evaluation of a qPCR detection method for citrinin in Liupao tea.

Penicillium is universal in dark tea, and Penicillium citrinum can produce a kidney toxin called citrinin (CIT). Determining CIT is difficult because of the complexity of the dark tea substrate and the diversity of CIT-producing fungi. Therefore, this study established a real-time PCR (qPCR) detection method for CIT-related synthetic genes (ctnD, orf1, ctnA, pksCT, orf5, orf7, and ctnG) in Liupao tea and determined the content of CIT in samples at different production stages and the toxin-producing abilities of fungi (Aspergillus oryzae, etc.

Effect of pile fermentation on the cells of Chinese Liupao tea: The first record of cell wall of Liupao tea on transmission electron microscope.

Fermentation often degrades the cell wall of dark tea, changes the carbohydrate components in the cell wall of tea, and thus affects the quality of tea. However, the lack of ultrastructural details limits our knowledge on the effect of fermentation on tea cell walls. Morphological studies of cell structures are important; thus, the cell wall of Liupao tea was analyzed under transmission electron microscopy for the first time, and the effects of different raw materials and fermentation methods on the cell wall and main carbohydrates of tea were compared.

Fatty acid composition of the methylotrophic yeast Komagataella phaffii grown under low- and high-methanol conditions.

In this study, we analysed the intracellular fatty acid profiles of Komagataella phaffii during methylotrophic growth. K. phaffii grown on methanol had significantly lower total fatty acid contents in the cells compared with glucose-grown cells.

Phenolic compounds, bioactivity, and bioaccessibility of ethanol extracts from passion fruit peel based on simulated gastrointestinal digestion.

Passion fruit peel, a potential source of bioactive compounds, has been used as food stabilizing agent. However, the phenolic composition and bioactivity of passion fruit peel have rarely been reported. The effects of simulated gastrointestinal digestion on the bioactive components, bioactivity and bioaccessibility of passion fruit peel ethanol extracts (PFPE) were investigated using high performance liquid chromatography-tandem mass spectrometry analysis (quasi-targeted metabolomics).

Purification, characterization, and bioactivity of Liupao tea polysaccharides before and after fermentation.

The raw tea polysaccharides (RLTPS) and the aged tea polysaccharides (ALTPS) from raw and aged Liupao tea were extracted and purified to afford five refined fractions. Component analysis revealed that the crude polysaccharide content from raw Liupao tea increased from 1.83 ± 0.

Evaluation of Mycoflora and Citrinin Occurrence in Chinese Liupao Tea.

Citrinin (CIT), a known nephrotoxic mycotoxin, is mainly produced by , , and species. It is a natural contaminant in cereal grains, foods, and feedstuff. Liupao tea (or Liubao tea) is a typical Chinese dark tea obtained via indigenous tea fermentation facilitated by microorganisms.

Analyses of fungal community by Illumina MiSeq platforms and characterization of Eurotium species on Liupao tea, a distinctive post-fermented tea from China.

Liupao tea is a distinctive Chinese dark tea obtained by indigenous tea fermentation facilitated by the symbiotic association of bacteria and fungi. The composition of fungal community in 4 Liupao tea samples stored for several years under natural microbial fermentation was evaluated by MiSeq sequencing. Taxonomic analysis revealed 3 phyla, 6 families, 8 genera.

Pro-coagulant activity of phenolic acids isolated from Blumea riparia.

The effects of extracts of the aerial part of Blumea riparia DC. and their phenolic acids on hemostasis were evaluated. The EtOAc fraction showed significantly reduced blood clotting time (CT) and tail bleeding time of transection (BT) of mice in vivo.