Search Results (97)

White tea infusion micro-nanoparticles (WTMPs) are important for colloidal stability, but the optimal strategy for their isolation and the mechanisms underlying their stability remain unclear. Here, a multi-indicator TOPSIS strategy was used to optimize ultrafiltration–centrifugation, and the best condition was identified as a 100 kDa membrane, 3000× g, and 20 min. The isolated WTMPs were not merely a concentrated form of white tea colloids (WTCs), but a selectively enriched fraction with remodeled composition, more regular morphology, more ordered intermolecular organization, and improved environmental stability. In particular, gallic acid (GA) was enriched, whereas caffeine (CAF) decreased markedly after isolation. Spectroscopy and molecular dynamics simulations further suggested that GA and CAF played different roles in the protein–polysaccharide network: GA was more favorable for cooperative interfacial stabilization, whereas CAF behaved more like a locally associated ligand. Overall, these results support a composition–structure–stability relationship for WTMPs and provide mechanistic insight into the selective enrichment of GA and the enhanced stability of the isolated micro-nanoparticle fraction. Full article

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease and a global public health concern, for which there is currently no effective method to inhibit its progression. The pathogenesis of NAFLD is related to hepatic lipid metabolism disorders and liver inflammation. Previous studies have shown that tea polysaccharides (TPS) have the ability to regulate lipid metabolism and control inflammation. This study aimed to observe the effect of TPS on ameliorating NAFLD in a mouse model and to reveal its underlying mechanisms. In the current study, male C57BL/6J mice were fed a high-fat diet and administered 100 mg/kg TPS daily by gavage for 14 weeks. Then, liver injury indicators and macrophage polarization markers were detected. The results revealed that TPS could significantly ameliorate the progression of NAFLD and decrease liver injury indicators. Moreover, we found that treatment of NAFLD model mice with TPS could skew liver macrophages polarization from M1 to M2 type, which inhibited pro-inflammatory cytokines production and liver inflammation. Mechanistically, TPS cannot directly regulate the polarization of liver macrophages, but instead promotes the production of butyric acid by gut microbiota, which in turn regulates macrophage polarization. These findings suggest that TPS ameliorates NAFLD-associated inflammation by modulating the gut–liver axis and promoting M2 macrophage polarization, laying the foundation for the potential of TPS in the development of health foods for NAFLD. Full article

Polygonatum cyrtonema Hua (PCH) is traditionally recognized as both an edible and medicinal food source. Its rhizomes contain numerous bioactive compounds, notably polysaccharides and flavonoids, which serve as key constituents in functional food development. However, the cultivation of PCH is often hindered by allelopathic effects, which diminish its quality and restrict its industrial application. To mitigate these allelopathic influences, three types of biochars derived from maize straw (MB), rice husk (RB), and tea stem (TB) were applied at concentrations of 0%, 2%, and 4%. Initially, the physicochemical properties of these biochars were characterized, followed by an evaluation of their impact on (1) the synthesis of quality-related components, secondary metabolites, and allelochemicals within PCH rhizomes and (2) the fundamental physicochemical properties and bacterial community structure of the PCH rhizosphere soil. The findings indicated that the application of 4% RB significantly enhanced the content of total polysaccharides by 48.5%, total flavonoids by 30.2%, total saponins by 28.6%, and total polyphenols by 18.3%, while concurrently reducing protein (PRO) and free amino acid (FAA) concentrations in the rhizomes. Non-targeted metabolomic analyses revealed that biochar amendments (1) upregulated metabolites involved in the citrate cycle and galactose metabolism pathways, thereby facilitating energy supply and precursors for polysaccharide biosynthesis; (2) downregulated metabolites involved in the arginine biosynthesis pathway, which is unfavorable for protein and amino acid synthesis; (3) decreased the abundance of six identified allelochemicals, including 5-hydroxy-L-tryptophan and andrographolide, with the most pronounced effect observed in the 4% TB treatment (T2); (4) improved soil physicochemical parameters such as pH, soil organic matter (SOM), total nitrogen (TN), and available potassium (AK); and (5) altered the rhizosphere bacterial community by enriching beneficial phyla, notably Myxococcota and Gemmatimonadota. These modifications in soil properties and bacterial community composition were closely associated with enhanced rhizome quality and a reduction in allelochemical accumulation. Collectively, the results of this study elucidate the potential mechanisms linking biochar application to allelopathy mitigation, optimization of soil microbial communities, and improvement of PCH rhizome quality. This research provides a theoretical basis for the production of high-quality PCH while concurrently minimizing allelochemical accumulation in its rhizomes. Full article

Tea offers health benefits, but some teas accumulate high fluoride (F), posing fluorosis risks. However, the roles of individual tea components in regulating F bioavailability remain unclear. This study investigated the effects of major tea constituents on F metabolism in male rats (n = 5/group) administered F (40 mg/L) alone or with graded doses of epigallocatechin gallate (EGCG, 150–450 mg/kg); theaflavins, thearubigins, and theabrownin (TFs, TRs, TB, 200–800 mg/kg each); tea polysaccharides (TPSs, 25–250 mg/kg); and calcium and aluminum (Ca, Al, 800–3200 µg/kg each) via gavage. Pharmacokinetic analysis of plasma F (0–480 min) and fecal F excretion were assessed. The result showed that high-dose EGCG (450 mg/kg) reduced C_max by 61.76% and total exposure (AUC_0–t) by 37.48% compared to the control, while significantly increasing fecal F by 26.79% (p < 0.05). TB (800 mg/kg) delayed F absorption by prolonging T_max from 18 to 30 min and reduced C_max by 35.38% (p < 0.05). TPS (250 mg/kg) decreased C_max by 51.72% and AUC_0–t by 24.38% (p < 0.05). Ca and Al (800–3200 µg/kg) reduced C_max by 39.19–69.62%, and low-dose aluminum (800 µg/kg) increased fecal F by 35.58% (p < 0.05). These findings elucidate distinct roles of tea constituents in mitigating F bioavailability, providing a scientific basis for tea safety assessment and dietary interventions against F overexposure. Full article

The work provides novel insight into the development of advanced antibacterial surfaces using the combination of essential oils, cinnamon oil, thyme oil, and tea tree oil, as well as their active compounds, including cinnamaldehyde, thymol, and terpinene-4-ol, embedded in the chitosan and sodium alginate matrix. All coatings obtained in a two-stage electrophoretic deposition process on stainless steel and titanium substrates were characterized by high adhesion strength. The microstructural differences between the coatings were mainly related to the size and location of the additives. Structural investigation showed the impact of individual oil components on intermolecular bonds between polysaccharide chains and the formation of molecular interactions in a specific spatial conformation. The surface of all coatings was minimally rough and had a hydrophilic character. A clear matrix-dependent trade-off between antibacterial efficacy and cytocompatibility was observed: alginate-based coatings achieved strong anti-Staphylococcus aureus activity (2.81 log CFU/mL) at the expense of increased cytotoxicity, while chitosan-based systems provided a more favorable cytocompatibility profile, maintaining cell viability above 70% for selected formulations. This work provides insight into the development of natural antibacterial surfaces by the combination of active compounds and shows the distinctions on many levels between the coatings with various polysaccharide matrices. Full article

This study investigated the extraction, enrichment, characterization, and antioxidant activities of Sargassum fusiforme polyphenols (SFPs). The optimal extraction process conditions of SFPs are as follows: an ethanol volume fraction of 28%, a liquid–solid ratio of 29 mL/g, an extraction temperature of 80 °C, and an extraction time of 3.2 h. After enrichment by D101 macroporous resin, the purity of SFPs increased from 1.20 ± 0.08% to 10.78 ± 0.25%, increasing by approximately 8 times. SFPs were mainly composed of polyphenols, flavonoids, and polysaccharides. Furthermore, after identification by HPLC-QQK-ESI-MS/MS, they were found to contain 11 phlorotannins (mainly of the fuhalol type), 2 flavonoids, etc. In three antioxidant evaluation systems (DPPH free radical scavenging ability, reducing power, and total antioxidant capacity), the enriched SFPs all exhibited superior activities compared to tea polyphenols. The research results provide a theoretical basis and experimental evidence for the development of a new type of food preservative based on SFPs. Full article

Pectins are high-value plant cell-wall polysaccharides with extensive applications in the food, pharmaceutical, textile, paper, and environmental sectors. Traditional extraction and processing methodologies rely heavily on harsh acids, high temperatures, and non-renewable solvents, generating substantial environmental and economic costs. This review consolidates recent advances across the entire Bacillus–pectinase value chain, from green pectin extraction and upstream substrate characterization, through process and statistical optimization of enzyme production, to industrial biocatalysis applications. We propose a practical roadmap for developing high-efficiency, low-environmental-footprint enzyme systems that support circular bioeconomy objectives. Critical evaluation of optimization strategies, including submerged versus solid-state fermentation, response surface methodology, artificial neural networks, and design of experiments, is supported by comparative data on strain performance, fermentation parameters, and industrial titers. Sector-specific case studies demonstrate the efficacy of Bacillus pectinases in fruit-juice clarification, textile bio-scouring, paper bio-bleaching, bio-based detergents, coffee and tea processing, oil extraction, animal feed enhancement, wastewater treatment, and plant-virus purification. Remaining challenges, including enzyme stability in complex matrices, techno-economic scale-up, and structure-guided protein engineering, are identified. Future directions are charted toward CRISPR-driven enzyme design and fully integrated circular-economy bioprocessing platforms. Full article

The genus Citrus consists of Tangerines (Citrus × reticulata), Mandarins (Citrus × reticulata), Oranges (Citrus × sinensis), Grapefruits (Citrus maxima), Lemons (Citrus × limon), and other citrus fruits. This study investigated the effects of 74 different citrus species and harvesting time on the quality of citrus dark tea using Hubei green brick tea as the raw material. Oranges (Citrus × sinensis) were found to outperform other species in improving the quality of citrus dark tea. Additionally, the impact of orange harvesting time (August to December) on the quality of orange dark tea was investigated by using the Peach leaf orange with the highest sensory score as the subject of the study. Results revealed that harvesting time can considerably impact the flavor quality of orange dark tea, but not its infusion color or scent. Specifically, the orange dark tea processed with September-harvested Peach leaf orange exhibited a strong fruity scent, a sweet and smooth flavor, and a harmonious tea and fruit aroma. With the delay of harvesting time, a downtrend was observed in the content of soluble proteins, flavonoids, hesperidin, synephrine, and limonin, as well as total volatile components, with the largest decrease in synephrine and flavonoids. However, the polysaccharide content increased in the peel of Peach leaf orange. Functional analysis revealed that the delay of harvesting time can diminish the inhibitory capacity of orange-dark tea on α-glucosidase and α-amylase. Organoleptic quality and physiological activity analysis demonstrated September as the optimal time for harvesting Peach leaf oranges for processing orange dark tea. Full article

Current food packaging, primarily made of non-biodegradable plastics, significantly contributes to environmental pollution. New packaging systems for food applications from biopolymers and/or with multifunctional properties are being developed as substitutes for synthetic polymers. The increasing concern over the environmental effects of packaging waste is driving a transition toward renewable packaging materials. Edible films and coatings play a vital role in maintaining food quality by preventing the loss of aroma, flavour, and important components, while also extending shelf life. Biopolymers, including polysaccharides, proteins, and lipids, are gaining attention as the future of packaging due to the environmental issues linked to petrochemical-based plastics. Modern packaging should not only protect products but also be biodegradable, recyclable, and have a minimal ecological impact. This review comprehensively summarises edible packaging in the form of single-use, fast-dissolving pouches for food applications as a circular approach and a sustainable solution in food technology. Innovations have resulted in the development of a unique packaging solution made from renewable sources. This packaging utilises plant and animal by-products to create edible films and pouches that are easy to seal. Edible packaging is emerging as a sustainable alternative, designed to simplify food packaging while minimising waste. Fast-dissolving scalable packaging, particularly edible films that dissolve in water, is used for individual servings of dry foods and instant beverages. This includes items like breakfast cereals, instant coffee or tea, and various powdered products. Additionally, there is an innovative approach to single-use packaging for oils and powders, leveraging the convenience and efficiency of these fast-dissolving films. Edible pouch packaging, made from safe and edible materials, provides a biodegradable option that decomposes naturally, thereby reducing pollution and the need for disposal. Full article

Although coagulation can enhance sludge dewatering performance, it often leads to dense flocs, hindered water release, and secondary pollution of the sludge cake. In this study, three types of biochar-based skeleton materials, tea waste-derived biochar (TB), PAC sludge-derived biochar (PB), and their mixture (MB), were employed in combination with polyaluminum chloride (PAC) to improve sludge permeability and water release capacity. The results showed that PAC alone reduced the water content (Wc) and capillary suction time (CST) of raw sludge (RS) from 79.07% and 97.45 s to 69.45% and 42.30 s, respectively. In contrast, biochar–PAC composite conditioning achieved further enhancement. Among them, the TBP group (10% DS TB + 4% DS PAC) exhibited the best performance, with Wc and CST reduced to 58.73% and 55.65 s, reaching the threshold for deep dewatering (Wc < 60%). Low-field nuclear magnetic resonance (LF-NMR) analysis revealed an enhanced transformation from bound to free water, improving water mobility. Zeta potential and particle size analysis indicated that biochar promoted electrostatic neutralization and adsorption bridging. Rheological and EPS measurements demonstrated significant reductions in yield stress and apparent viscosity, alongside the enhanced release of proteins and polysaccharides into soluble EPS (S-EPS). Scanning electron microscopy and pore structure analysis further confirmed that biochar formed a stable porous skeleton (pore diameter up to 1.365 μm), improving sludge cake permeability. In summary, biochar synergizes with PAC through a “skeleton support–charge neutralization–adsorption bridging” mechanism, reconstructing sludge microstructure and significantly improving deep dewatering performance. Full article

Porphyromonas gingivalis is a key periodontal pathogen whose cysteine proteases, gingipains (Rgp and KGP), are essential for nutrient acquisition and virulence. Targeting gingipains may attenuate bacterial pathogenicity and prevent related systemic diseases. This paper aimed to review advances in food-derived natural products that inhibit P. gingivalis or gingipains, with emphasis on mechanisms, potency, and translational potential. A literature search of several databases identified 64 studies on food-derived compounds demonstrating in vitro, in vivo, or clinical effects against P. gingivalis or gingipains. The results showed that tea polyphenols and dihydrochalcones (e.g., phloretin and phlorizin) inhibited gingipain activity, and a variety of food-derived natural products (especially polyphenols and polysaccharides) suppressed the growth, survival, biofilm formation, and virulence of P. gingivalis. Structure–activity relationships suggest galloyl moieties and dihydrochalcone scaffolds enhance gingipain inhibition. Polysaccharides and alkaloids exhibited anti-adhesion or protease inhibition, though with limited potency data. In summary, food-derived natural products represent promising gingipain inhibitors. These inhibitors have potential structure–activity relationships, indicating that food-derived natural products have considerable research prospects. Future research should prioritize structure-based discovery and structure optimization to realize their therapeutic potential. Full article

Fermentation plays a pivotal role in shaping the flavor and overall quality of Pu-erh tea, a microbially fermented dark tea. Here, we monitored physicochemical properties, chemical constituents, and microbial succession at 15 fermentation time points. Amplicon sequencing identified Staphylococcus, Bacillus, Kocuria, Aspergillus, Blastobotrys, Thermomyces, and Rasamsonia as dominant genera, with prokaryotic communities showing greater richness and diversity than eukaryotic ones. Beta diversity and clustering analyses revealed stable microbial structures during late fermentation stages. Non-targeted metabolomics detected 347 metabolites, including 56 significantly differential compounds enriched in caffeine metabolism and unsaturated fatty acid biosynthesis. Fermentation phases exhibited distinct metabolic patterns, with volatile aroma compounds (2-acetyl-1-pyrroline, 2,5-dimethylpyrazine) and health-beneficial fatty acids (linoleic acid, arachidonic acid) accumulating in later stages. OPLS-DA and KEGG PATHWAY analyses confirmed significant shifts in metabolite profiles relevant to flavor and biofunctionality. RDA revealed strong correlations between microbial taxa, environmental parameters, and representative metabolites. To functionally verify microbial contributions, 17 bacterial and 10 fungal strains were isolated. Six representative strains, mainly Bacillus and Aspergillus, exhibited high enzymatic activity on macromolecules, confirming their roles in polysaccharide and protein degradation. This integrative multi-omics investigation provides mechanistic insights into Pu-erh tea fermentation and offers a scientific basis for microbial community optimization in tea processing. Full article

The increasing demand for environmentally friendly alternatives to conventional plastic packaging has driven interest in the development of biodegradable edible films with functional properties. In this work, edible blend films were developed based on fish gelatin (FG), soluble soybean polysaccharide (SSPS), and tea polyphenol (TP) for active food packaging applications. The FG/SSPS/TP films were prepared by solvent casting and characterized in terms of their structural, mechanical, optical, thermal, and barrier properties. FTIR, SEM, and XRD analyses revealed TP-induced morphological and structure changes in the biopolymer matrix. The incorporation of TP significantly enhanced the antioxidant activity and UV-shielding properties of the films, while also modifying their flexibility and surface hydrophilicity. The packaging performance of FG/SSPS/TP films was evaluated using beef tallow as a model food product. Compared to neat FG/SSPS and polyethylene films, the FG/SSPS/TP films effectively suppressed lipid oxidation of the samples during storage. The results demonstrated that the prepared FG/SSPS/TP films possess strong potential for use as edible and active packaging materials for food products. Full article

In this study, the ultrasonic-assisted extraction of deep eutectic solvents (UADES) for tea polysaccharides was optimized, and their physicochemical properties and antioxidant activities were analyzed. The optimal DES comprised choline chloride (CC) and ethylene glycol (EG) in a molar ratio of 1:3, with a water content of 40%. The optimized condition was an extraction temperature of 61 °C, an ultrasonic power of 480 W, and an extraction time of 60 min. The UADES extraction rate of polysaccharides (ERP) was 15.89 ± 0.13%, significantly exceeding that of hot water (HW) extraction. The polysaccharide content in the UADES-extracted tea polysaccharides (UADESTPs) was comparable to that of hot-water-extracted tea polysaccharides (HWTPs) (75.47 ± 1.35% vs. 74.08 ± 2.51%); the UADESTPs contained more uronic acid (8.35 ± 0.26%) and less protein (12.91%) than HWTP. Most of the UADESTPs (88.87%) had molecular weights (Mw) below 1.80 × 10³ Da. The UADESTPs contained trehalose, glucuronic acid, galactose, xylose, and glucose, with molar ratios of 8:16:1:10. The free radical scavenging rate and total reducing power of the UADESTPs were markedly superior to those of the HWTPs. Moreover, the UADESTPs had a better alleviating effect on H₂O₂-induced oxidative injury in HepG2 cells. This study develops an eco-friendly and efficient extraction method for tea polysaccharides, offering new insights for the development of tea polysaccharides. Full article

Diabetes is one of the major non-communicable diseases whose physiological complications are linked with a higher risk of mortality amongst the adult age group of people living globally. This review article documents updated pharmacological evidence and insights into the antidiabetic mechanisms of green, black, white, oolong, and pu-erh teas via reported experimental and clinical models toward encouraging their use as a complementary nutraceutical in managing the biochemical alterations found in the onset and progression of diabetes. Peer-reviewed articles published in “PubMed”, “Google Scholar”, and “ScienceDirect” from 2010 and beyond that reported the antidiabetic, antilipidemic, and digestive enzyme inhibitory effects of the selected tea types were identified. The keywords used for the literature search comprise the common or scientific names of the tea and their corresponding bioactivity. Although teas portrayed different antidiabetic pharmacological properties linked to their bioactive components, including polyphenols, polysaccharides, and amino acids, the type of phytochemical found in each tea type depends on their processing. Green tea’s strong carbohydrate digestive enzyme inhibitory effect was linked with Ellagitannins and catechins, whereas theaflavin, a main ingredient in black tea, increases insulin sensitivity via enhancing GLUT4 translocation. Theabrownin in pu-erh tea improves FBG and lipid metabolism, while chemical components in white tea attenuate prediabetes-mediated reproductive dysfunctions by improving testicular tissue antioxidant capabilities. Based on the body of findings presented in this article, it is evident that integrating tea intake into daily food consumption routines could offer a promising practical solution to support human health and well-being against diabetes disease. Full article