Search Results (193)

This study utilizes waste wheat straw fibers and discarded tea bags as novel raw materials for developing new thermal insulation and sound absorption composites. Wood adhesive (WA) is used to bind the polymer raw materials. Loose polymers and different composites are experimentally developed in different concentrations. Sound absorption and thermal conductivity coefficients are obtained for the developed boards. Bending moment analysis and the moisture content of the boards are reported in addition to a microstructure analysis of the straw fibers from wheat. The results indicate that as the wheat straw fiber’s percentage increases in the composite, the thermal conductivity coefficient decreases, the flexure modulus decreases, the sound absorption coefficient increases at some frequencies, and the moisture content increases. The range of thermal conductivity and the noise reduction coefficient are 0.042–0.073 W/m K and 0.35–0.6 at 24 °C for the polymer raw materials, respectively. The corresponding values for the composites are 0.054 and 0.0575 W/m K and 0.45–0.5, respectively. The maximum moisture content percentages for the polymers and composites are 6.5 and 1.15, respectively. The composite flexure modulus reaches maximum and minimum values of 4.59 MPa and 2.22 MPa, respectively. These promising results promote these polymer and composite sample boards as more convenient insulation materials for green buildings and could replace the conventional petrochemical thermal insulation ones. Full article

The large-scale disposal of loquat (Eriobotrya japonica Lindl.) flowers during fruit thinning represents a significant waste of bioactive resources. This study systematically evaluated how three processing methods—fresh (FS), heat-dried (HD), and freeze-dried (FD) treatments—affect the flavonoid composition and antioxidant capacity of loquat flower extracts, with the aim of developing value-added, sugar-free functional tea ingredients. Using UPLC-MS/MS and DPPH assays, we analyzed both pre-(FS/HD/FD) and post-extraction samples (FSP/HDP/FDP) to assess processing-specific metabolic signatures and extraction efficiency. The results revealed that heat-dried powder (HDP) exhibited the highest total flavonoid content and DPPH scavenging capacity (615.24 µg Trolox/g), attributed to enhanced release of stable compounds like quercetin. Freeze-dried powder (FDP) better preserved heat-sensitive flavonoids, such as catechin-(4α→8)-gallocatechin and naringenin, but showed lower overall antioxidant activity. Multivariate analysis confirmed distinct clustering patterns, with heat-drying favoring flavonoid extractability while freeze-drying maintained metabolic diversity. These findings demonstrate that processing methods significantly influence bioactive compound retention and functionality, with heat-drying offering optimal balance between yield and practicality for industrial applications. This work provides a scientific foundation for upcycling loquat flowers into standardized nutraceutical ingredients, addressing both agricultural waste reduction and the growing demand for natural functional foods. Full article

Microorganisms metabolising low-value carbon sources can produce a diverse range of bio-based and biodegradable materials compatible with circular economy principles. One such material is bacterial cellulose (BC), which can be obtained in high purity through the fermentation of sweetened tea by a Symbiotic Culture of Bacteria and Yeast (SCOBY). In recent years, there has been a growing research interest in SCOBYs as a promising solution for sustainable material design. In this work, we have explored a novel method to grow SCOBYs vertically using a waste-based scaffold system. Waste sheep wool and cotton fabric were soaked in a SCOBY infusion to serve as scaffolds, carrying the infusion and facilitating vertical growth through capillary forces. Remarkably, vertical membrane growth up to 5 cm above the liquid–air interface (LAI) was observed after just one week. Membranes with different microstructures were found in sheep wool and cotton, randomly oriented between the scaffold fibre, resulting in a high surface area. This study demonstrated that vertical growth in scaffolds is possible, proving the concept of a new method of growing composite materials with potential high-value applications in biomedicine, energy storage, or filtration. Full article

This research explored the potential of pressurised liquid extraction techniques for valorising herbal orange peel dust (OPD) waste from the filter tea industry. A series of experiments were conducted, varying the temperature (120–220 °C) and solvent (water and 50% (v/v) ethanol), while pressure and time were kept constant. Afterward, the obtained extracts were analysed by LC-ESI-MS/MS for determining the chemical composition. The highest concentrations of the most dominant compounds, the antioxidants hesperidin (662.82 ± 22.11 mg/L) and naringin (62.37 ± 2.05 mg/L), were found at specific temperatures using subcritical water extraction. In silico studies indicated that these compounds could interact with sirtuin-1 and growth factor beta receptors, suggesting potential anti-ageing benefits for skin. In vitro experiments on rat hepatoma cells (H4IIE) revealed that OPD extracts had antitumor potential, inhibiting cell proliferation and altering cell morphology. These findings underscore the importance of temperature and extraction technique in obtaining antioxidant-rich extracts with pharmacological potential. The resulting extracts, obtained using green solvents, show promise for cosmetic applications, though further in vivo studies are needed to confirm their therapeutic efficacy. Full article

The adverse effects of polyethylene packaging waste on environmental pollution have driven academia to explore biodegradable active packaging (AP) solutions. In the present study, hybrid electrospun nanofiber (HENF) AP was produced using 30% gelatin (GE) combined with 1%, 2%, and 3% green tea extract powder (GTEP), termed HGGTNF. HENF was applied to Hanwoo beef as an AP to assess physicochemical, textural, microbiological, and sensory qualities in comparison to traditional polyethylene packing (PEP). The findings illustrate that the HGGTNF group maintained a significantly (p < 0.05) stable pH (5.71 ± 0.02–5.78 ± 0.01), lower drip loss (DL) (1.15% ± 0.00 to 1.20 ± 0.02%), and cooking loss (CL) (18.13 ± 0.03% to 19.91 ± 0.01%) compared to PEP (pH = 5.66 ± 0.02, DL = 1.21 ± 0.01%, CL = 20.26 ± 0.03%). Moreover, HGGTNF improved oxidative stability, especially at elevated doses (2% and 3%). In HGGTNF groups, there was a decreasing (p < 0.05) trend in thiobarbituric acid reactive substances (TBARS) (0.23 ± 0.01 to 0.26 ± 0.01 mg-MDA/kg), compared to the PEP group (0.29 ± 0.01 mg-MDA/kg). Oxidative stability improved the fatty acid profile, preserved color intensity (Chroma), and inhibited discoloration (h°) in HGGTNF (2% & 3%) compared to PEP. Furthermore, HGGTNF groups had stable meat tenderness and better chewiness than PEP. Stabilization of tenderness was due to diminished cathepsin activity (5822.80 ± 20.16 and 6009.80 ± 3.90 U/mg protein in the HGGTNF 2% and 3% groups, respectively). The HGGTNF 3% sample exhibited a decrease in total coliform counts (TCC) (0.74 ± 0.04 log CFU/g), total viable counts (TVC) (1.38 ± 0.05 log CFU/g), and total yeast and mold count (TYMC) (1.59 ± 0.06 log CFU/g) compared to other groups, indicating efficient antimicrobial efficacy. An increasing (p < 0.05) trend was observed in umami and richness taste traits for the HGGTNF 3% treated sample. The above findings underscore the potential applicability of HGGTNF as AP to enhance beef shelf life and meat quality attributes. Full article

Although there are studies on the use of different tea extracts in animal diets, there are no studies on the use of fermented black tea factory production waste (FTFW) in rodent diets. This study aims to evaluate the effects of FTFW, considered an environmentally hazardous waste, in standard rat diets regarding nutritional, histopathological, and biochemical parameters. In this study, 40 male Wistar albino rats (70 days old, with a live weight of 200–250 g) were divided into four groups, each containing 10 rats. They were fed standard rat diets for 63 days, with varying amounts (0%, 3%, 5%, and 10%) of tea production waste. At the end of the experiment, biochemical analysis of blood and histopathological analysis of all organs were performed. There was no significant difference between the groups in terms of body weight, internal organ weights, or serum biochemical parameters (p > 0.05). No pathological findings were observed in any of the groups. The group receiving 10% tea waste, which had the highest total polyphenol level (1.42 ppm), also showed the highest serum total antioxidant status (TAS) (p < 0.05). In contrast, this group had the lowest total oxidant status (TOS) and oxidative stress index (OSI) levels (p < 0.05). The study concluded that FTFW can be included in the pellet diet of rats without changing their general health status and that a potential environmental pollutant can be used in rat diets. Full article

Commercial progress concerning biobased materials has been slow, with success depending on functionality and emotional responses. Emotional interaction research provides a novel way to shift perceptions of biobased materials. This study proposes a human-centered emotional design framework using biobased tea waste to explore how sensory properties (form, color, odor, surface roughness) shape emotional responses and contribute to sustainable wellbeing. We used a mixed-methods approach combining subjective evaluations (Self-Assessment Manikin scale) with physiological metrics (EEG, skin temperature, pupil dilation) from 24 participants. Results demonstrated that spherical forms and high surface roughness significantly enhanced emotional valence and arousal, while warm-toned yellow samples elicited 23% higher pleasure ratings than dark ones. Neurophysiological data revealed that positive emotions correlated with reduced alpha power in the parietal lobe (αPz, p = 0.03) and a 0.3 °C rise in skin temperature, whereas negative evaluations activated gamma oscillations in central brain regions (γCz, p = 0.02). Mapping these findings to human factors engineering principles, we developed actionable design strategies—such as texture-optimized surfaces and color–emotion pairings—that transform tea waste into emotionally resonant, sustainable products. This work advances emotional design’s role in fostering ecological sustainability and human wellbeing, demonstrating how human-centered engineering can align material functionality with psychological fulfillment. Full article

In the past decade, the governance of urban space, in connection with the triad, environmental, social, and governance (ESG), has trended towards greater humanization to achieve urban sustainability and social harmony in China. With a focus on the case of the Waliu Community (Zhengzhou), this study investigates the evolution of environmental governance in its vending zones. As one of the earliest Chinese communities to transition from spatial exclusion to spatial inclusion and then to spatial self-management in environmental governance, the Waliu Community established two specific vending zones, Tea City and Shenglong. These zones have transformed the governing mindset of the community’s urban environment. The latest strategy of spatial self-management enables urban low-income groups to participate in the co-governance of the urban environment. The research methods used in this study range from spatial analysis and direct observation to semi-structured interviews; data and information are collected through field notes, official records, and designed questionnaires. The study investigates key indicators spatial utilization efficiency, vendor livelihood, social order and safety, and stakeholder satisfaction. Results demonstrate that spatial self-management effectively optimizes community traffic flow, enhances waste collection efficiency, and fosters consensus and collaboration among stakeholders. It is concluded that spatial self-management facilitates the sustainable production of urban spaces for their users within China’s complex urban contexts. Full article

As part of the European Green Deal, the Farm to Fork strategy was introduced with the idea that environment, agriculture and food are interconnected topics. Reducing the use of synthetic fertilizers by 20% before 2030 through the adoption of circular economy principles is one of the goals to be achieved. There are several bioproducts that can be obtained from the valorization of agro-industrial wastes used to increase crop yields under low-fertilizer applications. However, the aim of this review is to describe production methods and the use of compost tea on horticultural crops to understand its real potential in providing plant growth support. The effects of compost tea on crops can vary widely depending on the waste material used, compost quality, compost tea production process and parameters, and the interaction between horticultural species and compost tea application dose. Therefore, because of this heterogeneity, it is possible that we would achieve real, positive impacts on the environment and horticultural production if there were more collaboration between the research sector and private farms. This collaboration would allow the development of protocols for compost tea production and customized use according to real farm needs. This would reduce both the costs associated with the disposal of waste produced on the farm and reduce the costs associated with the supply of synthetic fertilizers. The adoption of on-farm guidelines for compost tea use would achieve a balanced trade-off between agricultural productivity and environmental sustainability. The literature review shows that the most-used dilution ratios, regardless of the type of starting compost, range from 1:5 to 1:10 compost–water (v/v). Although a complete understanding of the biostimulatory mechanisms activated by compost tea is lacking, the application of this bioproduct would improve the physiological and productive performance of many horticultural species of interest, especially under suboptimal conditions such as organic production. Full article

Low-grade tea, often underutilized due to its coarse texture and limited bioavailability, represents a significant resource waste. This study systematically investigated the synergistic effects of steam explosion (SE) and superfine grinding on enhancing the structural deconstruction, powder property, instant solubility, and diffusivity of low-grade. SE treatment induced critical physicochemical modifications, including hemicellulose degradation, lignin recondensation, and cellulose crystalline reorganization, which significantly weakened the lignocellulosic matrix. Subsequent superfine grinding via ball milling achieved ultrafine particles, with median diameter D₅₀ = 10.4 ± 0.17 μm, and almost completely destroyed the cell wall by 99.9%. Extraction kinetics revealed that SE-ball milling synergistically accelerated the diffusion behavior of bioactive compounds, reducing equilibrium time by 2~4 times and increasing maximum yields of polysaccharides, polyphenols, caffeine, and water-soluble solids by 9~25% compared to untreated samples. Homogenization combined with 0.08 mg/mL CMC-Na further improved the suspension stability of tea powder and reduced its centrifugal sedimentation to 9.85%. These findings demonstrate a scalable strategy to transform low-grade tea into high-value ingredients with enhanced accessibility and solubility of bioactive compounds, offering promising applications in instant beverages, fortified foods, and nutraceuticals. Full article

Tea saponin is a kind of natural non-ionic surfactant. Saponins were extracted from tea seed cake using an ultrasonic-assisted enzymatic method. The optimization of the tea saponin extraction procedure was conducted by using the response surface method to increase the yield. Study results indicated that the maximum yield of tea saponin was 69.81 mg/g under the optimum conditions of an enzyme concentration of 0.67%, a solvent-to-material ratio of 16.82 mL/g, an extraction temperature of 58.14 °C and an extraction time of 1.89 h. The surface activity experimental study results indicated that the critical micelle concentration of tea saponin was 0.5 g/L at 30 °C, and the lowest surface tension was 39.61 mN/m. The surface tension and CMC of tea saponin remained basically unchanged between 30 °C to 60 °C. When the pH of the solution was slightly acidic, the surface tension of tea saponin decreased significantly, while the CMC remained almost unchanged. Tea saponin has good salt and hard water resistance, and its surface tension decreases to a certain extent in both saltwater and hard water. The foam volume of tea saponin can reach 490 mL, with a half-life of 2350 s, and the foam is relatively stable. The combination of tea saponin and other surfactants has a certain synergistic effect. The critical micelle concentration of its complex system with the natural surfactant rhamnolipids can increase by 69.23%, and the surface tension can be reduced to a minimum of 22.56 mN/m. Moreover, by using the proposed method, the foam performance and stability of the system have been improved to a certain extent. This has significant practical significance for fully utilizing and developing waste camellia dried cake resources. Full article

The growing advocacy for greener climates, coupled with increasing global energy demand driven by urbanization and population growth, highlights the need for sustainable solutions. Repurposing food wastes as substrates offers a promising approach to enhancing cleaner energy generation and promoting a circular economy. This study investigated the potential of spent coffee grounds (SC) and biosolids cake (BS) from tea wastes as substrates for producing valuable fuels and chemicals through acetone–ethanol–butanol (ABE) fermentation. Clostridium beijerinckii NCIMB 8052 was used to ferment 100% and 50% hydrolysates derived from Parr-treated enzyme-hydrolyzed (PEH, PEH50), Parr-treated non-hydrolyzed (PNEH, PNEH50), and non-Parr-treated hydrolyzed (NPEH) SC wastes, as well as enzyme-hydrolyzed (BSH, BSH50) and non-hydrolyzed BS wastes (NBH, NBH50). Fermentation of unmodified hydrolysates by C. beijerinckii was poor. Following CaCO₃ modification of SC and BS hydrolysates, ABE titer, yield, and productivity increased, with the highest values obtained with PEH50 and NBH. Specifically, CaCO₃ modification of SC hydrolysates led to increased butanol titer, yield, and productivity in PEH50, while the NBH exhibited higher butanol yield and productivity than the non-CaCO₃-modified hydrolysates. Additionally, H₂ gas production with PEH50 and NBH was 1.41- and 1.13-fold higher, respectively, than in other hydrolysates. These findings suggest that SC and BS hydrolysates can be valorized to butanol and hydrogen gas and, thereby, can contribute to global food wastes management, energy sustainability, and cost-effective biofuel production. Full article

This study investigates the potential use of biochar derived from residues—such as spruce wood, spent coffee grounds, tea waste, and nutshells—as a sustainable coal substitute—to enhance the decarbonization of European energetic systems and decrease the dependence on fossil fuels. The biomasses were pyrolyzed at 250–550 °C, analyzed for calorific value and composition, and evaluated for energy retention and mass loss. The results show significant energy density improvements, with optimal temperatures varying by material (e.g., spruce wood reached 31.56 MJ·kg⁻¹ at 550 °C, retaining 21.84% of its mass; spent coffee grounds peaked at 31.26 MJ·kg⁻¹ at 350 °C, retaining 37.53%). Economic analysis confirmed pyrolyzed biomass as a cost-effective alternative to coal, especially considering emission allowance costs. Integrating biomass pyrolysis into regional energy systems supports decarbonization, reduces emissions, and advances us towards a circular economy. Full article

The essential amino acid tryptophan yields a plethora of secondary metabolites with key roles in plants and animals. Its fate in different living organisms is crucial for their own health, and metabolic profiling is a valuable tool for investigating it. Among the various metabolites, those retaining the indole structure were examined for qualitative and quantitative profiling. Liquid chromatography coupled with a tandem mass spectrometry detector with an electrospray ionization source (HPLC-ESI-MS/MS), acquiring in multiple reaction monitoring (MRM) mode, was used to develop a selective and sensitive method for the simultaneous analysis of tryptophan and 10 indole structure-retaining metabolites of it. Satisfactory values were obtained for linearity (R² ≥ 0.99 for all compounds except two), sensitivity (LOD, within 6–31 ng/mL, and LOQ, within 17–94 ng/mL, where minimum and maximum values were relative to serotonin and 5-methoxytryptamin, respectively), reproducibility (interday and intraday precision and accuracy), and effect of the matrix (recovery and matrix effect). The method was then successfully applied to the analysis of different types of beverage, such as herbal products, like Eschscholzia californica and a sleep herbal tea marketed with added melatonin (consumed to reduce anxiety and improve sleep quality), and fermented beverages, like beer and kefir. High amounts of tryptophan (from 77 ng/mL in kefir to 26,974 ng/g in the sleep herbal tea) followed by lower contents of serotonin (from 29 ng/mL in kefir to 2207 ng/g in the sleep herbal tea), were found in all samples along with the serotonin pathway-related compounds 5-hydroxytryptophan and tryptamine. Melatonin was detected in the plant matrix Eschscholzia c. for the first time to our knowledge (446 ng/g) and in the fermented beverages (96 ng/mL in beer and 39 ng/mL in kefir), regardless of their vegetable or animal origin, along with the melatonin route metabolites 5-methoxytryptamine and tryptophan ethyl ester. The amount of melatonin in the sleep herbal tea (556,464 ng/g) was in strong agreement with the declared content. Suggested applications include the search for biomarkers in phytochemical characterization, mechanistic studies of tryptophan’s chemistry, valorization of foods, beverages, and tryptophan-rich agro-food by-products and waste for nutraceutical and pharmacological purposes. Full article

Active packaging using an edible coating could be an essential and sustainable alternative solution to preserve the properties of fruits and to prevent food loss and food waste. Fruits generate significant food wastes and losses. Reducing food waste is a global priority. For this research, nature-based solutions (NBSs) were applied, using micro-sized chitosan (CsMPs) and selenium microparticles (SeMPs), which are green-synthesized from black tea leaf extracts, and thyme essential oil. In this study, the effects of the new generation active food preservative coating agents formed from combinations of micro-sized chitosan (CsMPs) and selenium (SeMPs), and thyme essential oil (Oil) on the quality of “0900 Ziraat” sweet cherry fruits after harvest were investigated. After the fruits were coated with edible colloid solution, they were stored at 4 °C and 21 °C for 20 days, and quality parameter analyses were performed on days 0, 5, 10, 15, and 20. As a result of this study, it was determined that the application of CsMPs + SeMPs and the subsequent application of CsMPs + SeMPs + Oil from colloid solution coatings reduced weight loss, respiration, and decay rates. Also, it was determined that these applications were the most effective in preserving color values (L*, chroma, and hue), fruit firmness, total soluble solid (TSS) amount, acidity content and total phenolics, anthocyanin, and antioxidant capacity. These results show that CsMPs + SeMPs and CsMPs + SeMPs + Oil applications can be used as edible coatings to preserve the quality of sweet cherry fruits and extend their shelf life after harvest. This study’s results will contribute to obtaining micro-sized composite coating agents/agents produced with new technology to extend the shelf life. Full article