Analysis of Guard Cell Readouts Using Arabidopsis thaliana Isolated Epidermal Peels.

Stomata are pores surrounded by a pair of specialized cells, called guard cells, that play a central role in plant physiology through the regulation of gas exchange between plants and the environment. Guard cells have features like cell-autonomous responses and easily measurable readouts that have turned them into a model system to study signal transduction mechanisms in plants. Here, we provide a detailed protocol to analyze different physiological responses specifically in guard cells. We describe, in detail, the steps and conditions to isolate epidermal peels with tweezers and to analyze i) stomatal aperture in response to different stimuli, ii) cytosolic parameters such as hydrogen peroxide (H2O2), glutathione redox potential (E GSH), and MgATP-2 in vivo dynamics using fluorescent biosensors, and iii) gene expression in guard cell-enriched samples. The importance of this protocol lies in the fact that most living cells on epidermal peels are guard cells, enabling the preparation of guard cell-enriched samples. Key features • Isolation of epidermal peels as a monolayer enriched in guard cells • Measurement of cytosolic guard cell signaling component dynamics in isolated epidermal peels through fluorescent biosensor analysis • Gene expression analysis of guard cell-enriched isolated tissue.

From waste to wonder: exploring the hypoglycemic and anti-oxidant properties of corn processing by-products.

Introduction: The industrial processing of corn (Zeamays L.) generates by-products such as corn silk, straw peels, and straw core, which contribute to adverse environmental impacts. Our study aimed to investigate sustainable approaches for mitigating these effects by evaluating the hypoglycemic potential and mechanisms of ethyl acetate fractions derived from these corn derivatives. Methods: We employed glucose consumption assays, high glucose stress tests, UPLC-QE-Orbitrap-MS analysis, molecular docking, and simulations to assess their components and efficacy. Antioxidant capacities were evaluated using DPPH, FRAP, ABTS, and •OH scavenging assays. Results: Notably, the ethyl acetate fraction extracted from straw peels (SPE) exhibited a high concentration of flavonoids and phenolic compounds along with pronounced hypoglycemic activity and antioxidant capacity. SPE significantly enhanced glucose consumption in insulin-resistant HepG2 cells while protecting HUVECs against damage caused by high glucose levels. Molecular docking analyses confirmed the interaction between active compounds and α-glucosidase as well as α-amylase, while molecular dynamic simulations indicated stability at their binding sites. Discussion: In conclusion, the hypoglycemic and antioxidative properties observed in corn by-products such as straw peels, corn silk, and straw core can be attributed to the inhibition of α-glucosidase and α-amylase activities, coupled with their rich phenolic and flavonoid content. These findings highlight the potential of these by-products for applications in healthcare management and their sustainable utilization, demonstrating significant value in the use of agricultural residues.

The assessment of the impact of carboxytherapy and selected chemical peels on cosmetic defects and signs of aging of skin around eyes.

OBJECTIVE: The purpose of this study was to assess changes in skin elasticity and other skin defects related to the aging of skin around eyes following the use of combination treatment carboxytherapy and chemical peels (ferulic acid combined with ascorbic acid, lactobionic acid). MATERIAL AND METHODS: A total of 39 Caucasian patients were subjected to a series of five combination carboxytherapy and chemical peels treatments at weekly intervals. The Cutometer device was used to objectively measure skin elasticity. The assessment was supplemented by photographic documentation. RESULTS: A statistically significant improvement in skin elasticity assessed on the basis of R2 and R7 parameters (p < .0001, p = .001, respectively) was demonstrated after a series of five sessions of carboxytherapy combined with chemical peels. The improvement in the R2 parameter was observed in 82.1%, while R7 in 76.9% of study participants. It observed that the number of participants who benefited from treatment with ferulic acid and ascorbic acid was statistically higher compared with the second group (p = .036). Improved R2 values were reported in 100% of participants undergoing carboxytherapy combined with ferulic and ascorbic acid. CONCLUSION: Carboxytherapy in combination with chemical peels improved skin elasticity and can be used to reduce other skin defects.

Comparing the efficacy and safety of microneedling and its combination with other treatments in patients with acne scars: a network meta-analysis of randomized controlled trials.

This study aimed to analyze the efficacy and safety of microneedling (MN), both alone and in combination with other treatments, to refine the approach for treating acne scars using MN. We systematically searched Pubmed, Cochrane Library, Embase, and Web of Science for randomized controlled trials examining MN or its combinations in patients with acne scars. All statistical analyses were performed using Stata 18 software. A total of 24 studies involving 1546 participants were included. The analysis revealed that MN combined with chemical peels (CP) exhibited the best results in terms of degree of improvement, patient satisfaction, and treatment efficacy compared to other treatments examined, including MN alone, MN with hyaluronic acid (HA), MN with botulinum toxin­A (TA), MN with platelet-rich plasma (PRP), PRP alone, CP, and laser therapy. The results for MN combined with additional treatments were obviously better than for MN alone. Side effects such as erythema, pain, and post-inflammatory hyperpigmentation showed no significant differences across all treatments assessed.

Alginate Beads with Encapsulated Bioactive Substances from Mangifera indica Peels as Promising Peroral Delivery Systems.

Since various bioactive substances are unstable and can degrade in the gastrointestinal tract, their stabilization is crucial. This study aimed to encapsulate mango peel extract (MPE) into edible alginate beads using the ionotropic gelation method for the potential oral delivery of bioactive substances. Mango peels, generally discarded and environmentally harmful, are rich in health-promoting bioactive substances. The alginate beads were examined for entrapment efficiency, particle size, morphology, thermal stability, physiochemical interactions, release profile under gastrointestinal conditions, and antibacterial efficacy. The study demonstrated the successful encapsulation of MPE with an efficiency of 63.1%. The in vitro release study showed the stability of the alginate beads in simulated gastric fluid with a maximum release of 45.0%, and sustained, almost complete release (99.4%) in simulated intestinal fluid, indicating successful absorption into the human body. In both fluids, the MPE release followed first-order kinetics. Encapsulation successfully maintained the antibacterial properties of MPE, with significant inhibitory activity against pathogenic intestinal bacteria. This is the first study on MPE encapsulation in alginate beads, presenting a promising oral delivery system for high-added-value applications in the food industry for dietary supplements, functional foods, or food additives. Their production is sustainable and economical, utilizing waste material and reducing environmental pollution.

Enrichment of Fruit Peels' Nutritional Value by Solid-State Fermentation with Aspergillus ibericus and Rhizopus oryzae.

The fruit processing industry is responsible for disposing of huge amounts of byproducts, especially fruit peels (FPs), which are often discarded in landfills. Using FPs in biotechnological processes contributes to a circular economy, reducing the environmental burden of FPs and increasing the revenue of the fruit processing industry. This study was focused on upgrading the nutritional value of orange (OPs) and banana (BPs) peels by solid-state fermentation (SSF) with filamentous fungi. SSF factors (moisture, fermentation time, inoculum size, ammonium sulfate (AS), and corn steep liquor (CSL)) and fungi species (Aspergillus ibericus and Rhizopus oryzae) were studied by a variable screening Plackett-Burman design. Both fungi grew on untreated FPs, increasing their protein content and antioxidant activity. Moisture, AS, and CSL were further studied by a Box-Behnken design with A. ibericus. Fermented OPs at 70% moisture and 0.005 g/g AS increased their protein content by 200%, whereas BPs at 70% moisture and 0.005 g/g CSL increased by 123%. Fermented peels were enriched in protein, fiber, and minerals, with a low content of carbohydrates and soluble sugars. Fermented OPs and BPs showed higher antioxidant activity than unfermented peels. The SSF of these FPs is an innovative approach that contributes to obtaining rich nutrient-fermented peels for food.

Exploring feasibility of citric acid infused lignocellulosic waste derived from chestnut and water melon peels for phytofiltration of Eosin yellow dye from water.

The adsorption efficiency of cheap, ecofriendly, and easily available agro-waste, Trapa natans (Chestnut) and Citrullus lanatus (Watermelon) peels, has been investigated in their native forms (TNAT and CLAN) as well as citric acid impregnated forms (C-TNAT and C-CLAN), respectively, for the detoxification of toxic, deleterious, and carcinogenic Eosin yellow dye (EYD) from wastewater streams. Different operational parameters were optimized for the investigation of isothermal, kinetic and the thermodynamic models. R2 for sportive decontamination of Eosin by citric acid treated adsorbents were close to one, supporting the applicability of Langmuir, Temkin, and pseudo-second-order in this investigation. Maximum sorption capabilities were 222 and 667 mg/g for chemically treated bio-waste C-TNAT and C-CLAN, respectively, reflecting their efficient and promising performance, while Gibbs free energy revealed exothermic and spontaneous adsorption behavior. The kinetic statics for qe (cal) are quite close to qe (exp), indicating the viability and fitness of pseudo-second-order mechanisms. The present study suggests that both citric acid fabricated bio-waste C-TNAT and C-CLAN can be substantially employed to decontaminate persistent organic pollutants, like: Eosin yellow dye from wastewater using green approach to resolve socio-economic problems of developing countries.

Total triterpenoids from apple peels exert pronounced anti-breast-cancer activity in vivo and in vitro.

BACKGROUND: Apples are among the most nutritionally valuable fruits and have a history of use in traditional Chinese medicine. Triterpenoids, the primary bioactive compounds found in apples, demonstrate significant antitumor activity. RESULTS: Following enrichment and optimization, the total content of major triterpenoids in total triterpenoids from apple peels (ATT) reached 5.76 g kg-1. The growth of MDA-MB-231 xenograft tumors was significantly inhibited after treatment with ATT. Network pharmacology analysis conclusively identified a close association between the antitumor effect of ATT and the phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt) signaling pathway. Experimental validation using MDA-MB-231 cells and a xenograft nude mouse model confirmed that ATT suppressed tumor cell proliferation effectively by modulating the PI3K-Akt signaling pathway, which was consistent with the findings from network pharmacology. The total triterpenoids from apple peels also induced cell apoptosis by mediating the PI3K-Akt signaling pathway. CONCLUSION: The total triterpenoids from apple peels can inhibit tumor cell proliferation and induce cell apoptosis effectively through the PI3K-Akt signaling pathway, suggesting that ATT holds promise as a prospective therapeutic agent for breast cancer treatment. © 2024 Society of Chemical Industry.

Advances in valorization of sweet potato peels: A comprehensive review on the nutritional compositions, phytochemical profiles, nutraceutical properties, and potential industrial applications.

During food production, food processing, and supply chain, large amounts of food byproducts are generated and thrown away as waste, which to a great extent brings about adverse consequences on the environment and economic development. The sweet potato (Ipomoea batatas L.) is cultivated and consumed in many countries. Sweet potato peels (SPPs) are the main byproducts generated by the tuber processing. These residues contain abundant nutrition elements, bioactive compounds, and other high value-added substances; therefore, the reutilization of SPP holds significance in improving their overall added value. SPPs contain abundant phenolic compounds and carotenoids, which might contribute significantly to their nutraceutical properties, including antioxidant, antimicrobial, anticancer, prebiotic, anti-inflammatory, wound-healing, and lipid-lowering effects. It has been demonstrated that SPP could be promisingly revalorized into food industry, including: (1) applications in diverse food products; (2) applications in food packaging; and (3) applications in the recovery of pectin and cellulose nanocrystals. Furthermore, SPP could be used as promising feedstocks for the bioconversion of diverse value-added bioproducts through biological processing.

Evaluating the Efficacy and Safety of Alpha-Hydroxy Acids in Dermatological Practice: A Comprehensive Clinical and Legal Review.

The global market for alpha-hydroxy acids (AHAs) is undergoing significant expansion, propelled by increasing demand for skincare products that address aging and environmental damage. This review focuses on the dermatological applications of AHAs, particularly in cosmetic formulations like chemical peels. We have identified that AHAs, such as glycolic and lactic acids, enhance skin rejuvenation by promoting apoptosis in skin cells, boosting collagen and elastin synthesis, and improving skin texture and luminosity. Our comprehensive analysis reveals a nuanced understanding of AHAs' effectiveness across various skin types and conditions, demonstrating their broad utility in treating conditions like acne, hyperpigmentation, and photoaging. However, the optimal concentrations for therapeutic efficacy with minimal side effects are yet to be precisely defined, necessitating further research. Regulatory compliance is underscored as essential for the safe application of AHAs in cosmetics, with international guidelines recommending specific concentrations and pH levels to minimize potential skin irritation. In Conclusion, the review highlights the effectiveness of AHAs in cosmetic dermatology, emphasizing the necessity for continued research and rigorous regulatory adherence to maximize their safe and beneficial application worldwide.

PEDOT-Doped Mesoporous Nanocarbon Electrodes for High Capacitive Aqueous Symmetric Supercapacitors.

Poly(3,4-ethylenedioxythiophene) (PEDOT) and PEDOT-functionalized carbon nanoparticles (f-CNPs) were synthesized by in situ chemical oxidative polymerization and pyrolysis methods. f-CNP-PEDOT nanocomposites were prepared by varying the concentration of PEDOT from 1 to 20% by weight (i.e., 1, 2.5, 5, 10, and 20 wt%). Several characterization techniques, such as field-emission scanning electron microscopy (FESEM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), N2 Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analyses, as well as cyclic voltammetry (CV), galvanostatic charge discharge (GCD), and electrochemical impedance spectroscopy (EIS), were applied to investigate the morphology, the crystalline structure, the N2 adsorption/desorption capability, as well as the electrochemical properties of these new synthesized nanocomposite materials. FESEM analysis showed that these nanocomposites have defined porous structures, and BET surface area analysis showed that the standalone f-CNP exhibited the largest surface area of 801.6 m2/g, whereas the f-CNP-PEDOT with 20 wt% exhibited the smallest surface area of 116 m2/g. The BJH method showed that the nanocomposites were predominantly mesoporous. CV, GCD, and EIS measurements showed that f-CNP functionalized with 5 wt% PEDOT had a higher capacitive performance compared to the individual f-CNPs and PEDOT constituents, exhibiting an extraordinary specific capacitance of 258.7 F/g, at a current density of 0.25 A/g, due to the combined advantage of enhanced electrochemical activity induced by PEDOT doping, and highly developed porosity of f-CNPs. Symmetric aqueous supercapacitor devices were fabricated using the optimized f-CNP-PEDOT doped with 5 wt% of PEDOT as active material, exhibiting a high capacitance of 96.7 F/g at 1.4 V, holding practically their full charge, after 10,000 charge-discharge cycles at 2 A/g, thus providing the highest electrical electrodes performance. Hereafter, this work paves the way for the potential use of f-CNP-PEDOT nanocomposites in the development of high-energy-density supercapacitors.

Effects of Orange Peel Extract on Laccase Activity and Gene Expression in Trametes versicolor.

The genome of Trametes versicolor encodes multiple laccase isozymes, the expression of which is responsive to various conditions. Here, we set out to investigate the potential of orange peel extract as an inducer of laccase production in this white-rot fungus, in comparison to the previously identified inducing chemical compound, veratryl alcohol. For four geographically distinct T. versicolor strains, a positive correlation has been observed between their oxidative activity and incubation time in liquid cultures. The addition of 20% orange peel extract or 5 mM veratryl alcohol caused a rapid increase in the oxidative potential of T. versicolor M99 after 24 h, with a more pronounced effect observed for the orange peel extract. To elucidate the underlying molecular mechanisms of the induced laccase activity, a transcriptional gene expression analysis was performed for the seven individual laccase genes in T. versicolor, revealing the upregulation of several laccase genes in response to the addition of each inducer. Notably, the gene encoding TvLac5 demonstrated a substantial upregulation in response to the addition of 20% orange peel extract, likely contributing to the observed increase in its oxidative potential. In conclusion, our results demonstrate that orange peels are a promising agro-industrial side stream for implementation as inducing agents in large-scale laccase production with T. versicolor.

Recovery of Ellagic Acid from Pomegranate Peels with the Aid of Ultrasound-Assisted Alkaline Hydrolysis.

The pomegranate processing industry generates worldwide enormous amounts of by-products, such as pomegranate peels (PPs), which constitute a rich source of phenolic compounds. In this view, PPs could be exploited as a sustainable source of ellagic acid, which is a compound that possesses various biological actions. The present study aimed at the liberation of ellagic acid from its bound forms via ultrasound-assisted alkaline hydrolysis, which was optimized using response surface methodology. The effects of duration of sonication, solvent:solid ratio, and NaOH concentration on total phenol content (TPC), antioxidant activity, and punicalagin and ellagic acid content were investigated. Using the optimum hydrolysis conditions (i.e., 32 min, 1:48 v/w, 1.5 mol/L NaOH), the experimental responses were found to be TCP: 4230 ± 190 mg GAE/100 g dry PPs; AABTS: 32,398 ± 1817 µmol Trolox/100 g dry PPs; ACUPRAC: 29,816 ± 1955 µmol Trolox/100 g dry PPs; 59 ± 3 mg punicalagin/100 g dry PPs; and 1457 ± 71 mg ellagic acid/100 g dry PPs. LC-QTOF-MS and GC-MS analysis of the obtained PP extract revealed the presence of various phenolic compounds (e.g., ellagic acid), organic acids (e.g., citric acid), sugars (e.g., fructose) and amino acids (e.g., glycine). The proposed methodology could be of use for food, pharmaceutical, and cosmetics applications, thus reinforcing local economies.

Mandarin biochar-CO-TETA was utilized for Acid Red 73 dye adsorption from water, and its isotherm and kinetic studies were investigated.

Environmental pollution is a major issue today due to the release of dyestuff waste into the environment through industrial wastewater. There is a need for affordable and effective adsorbents to remove harmful dyes from industrial waste. In this study, Mandarin biochar-CO-TETA (MBCOT) adsorbent was prepared and used to remove Acid Red 73 (AR73) dye from aqueous solutions. The efficiency of dye removal was influenced by various factors such as solution pH, contact time, initial AR73 dye concentration, and MBCOT dosage. All experiments were conducted at 25 ± 2 °C, and the optimal pH was determined to be 1.5. The optimal conditions for dye removal were found to be an AR73 dye concentration of 100 mg/L, an MBCOT dosage of 1.5 g/L, and a contact time of 150 min, resulting in a 98.08% removal rate. Various models such as pseudo-first-order (PFO), pseudo-second-order (PSO), film diffusion (FD), and intraparticle diffusion (IPD) were used to determine the adsorption kinetics of AR73 dye onto MBCOT. The results showed that the PSO model best explains the AR73 dye adsorption. Furthermore, Langmuir and Freundlich's isotherm models were studied to explain the adsorption mechanism using experimental data. The adsorption capacities at equilibrium (qe) in eliminating AR73 dye varied from 92.05 to 32.15, 128.9 to 65.39, 129.25 to 91.69, 123.73 to 111.77, and 130.54 to 125.01 mg/g. The maximum adsorption capacity (Qm) was found to be 140.85 mg/g. In conclusion, this study demonstrates that biochar produced from mandarin peels has the potential to be an effective and promising adsorbent for removing AR73 dye from water.

Sustainable extraction of proteins from lime peels using ultrasound, deep eutectic solvents, and pressurized liquids, as a source of bioactive peptides.

The aim of this work was to develop, for the first time, sustainable strategies, based on the use of Ultrasound-Assisted Extraction, Natural Deep Eutectic Solvents, and Pressurized Liquid Extraction, to extract proteins from lime (Citrus x latifolia) peels and to evaluate their potential to release bioactive peptides. PLE showed the largest extraction of proteins (66-69%), which were hydrolysed using three different enzymes (Alcalase 2.4 L FG, Alcalase®PURE 2.4 L, and Thermolysin). The in vitro antioxidant and antihypertensive activities of released peptides were evaluated. Although all hydrolysates showed antioxidant and antihypertensive activity, the hydrolysate obtained with Thermolysin showed the most significant values. Since the Total Phenolic Content in all hydrolysates was low, peptides were likely the main contributors to these bioactivities. Hydrolysates were analyzed by UHPLC-QTOF-MS and a total of 98 different peptides were identified. Most of these peptides were rich in amino acids associated with antioxidant activity.

In silico pharmacokinetic and therapeutic evaluation of Musa acuminata peels against aluminium chloride-induced hepatotoxicity in adult BALB/c mice.

East Africa (Musa spp.), notably Musa acuminata, "Matooke" a staple and economically important food in the region. Here, 12 selected M. acuminata peels extract (MAPE) bioactive compounds were studied for hepatoprotective potentials in aluminium chloride-induced hepatoxicity in adult BALB/c mice. GC-MS analysis was used to identify active components of MAPE. In silico estimation of the pharmacokinetic, the GCMS-identified compounds' toxicity profile and molecular docking were compared with the standard (Simvastatin) drug. Hepatotoxicity was induced using aluminium-chloride treated with MAPE, followed by biochemical and histopathological examination. Twelve bioactive compounds 2,2-Dichloroacetophenone (72870), Cyclooctasiloxane 18993663), 7-Hydroxy-6,9a-dimethyl-3-methylene-decahydro-azuleno[4,5-b]furan-2,9-dione (534579), all-trans-alpha-Carotene (4369188), Cyclononasiloxane (53438479), 3-Chloro-5-(4-methoxyphenyl)-6,7a-dimethyl-5,6,7,7a-tetrahydro-4H-furo[2,3-c]pyridin-2-one (536708), Pivalic acid (6417), 10,13-Octadecadienoic acid (54284936), Ethyl Linoleate (5282184), Oleic acid (5363269), Tirucallol (101257), Obtusifoliol (65252) were identified by GC-MS. Of these, seven were successfully docked with the target proteins. The compounds possess drug likeness potentials that do not inhibits CYP450 isoforms biotransformation. All the docked compounds were chemoprotective to AMES toxicity, hERGI, hERGII and hepatotoxicity. The animal model reveals MAPE protective effect on liver marker's function while the histological studies show regeneration of the disoriented layers of bile ducts and ameliorate the cellular/histoarchitecture of the hepatic cells induced by AlCl3. The findings indicate that MAPE improved liver functions and ameliorated the hepatic cells' cellular or histoarchitecture induced by AlCl3. Further studies are necessary to elucidate the mechanism action and toxicological evaluation of MAPE's chronic or intermittent use to ascertain its safety in whole organism systems.

Optimising the recovery of phenolic compounds and antioxidant activity from orange peels through solid-state fermentation.

It is widely recognised that orange peels contain a considerable quantity of phenolics, primarily in the form of glycosides. The process of fermentation holds potential as a viable method for extracting phenolic compounds and facilitating their biotransformation into novel metabolites. The aim of this study was to assess the enhanced release of phenolic compounds through the process of solid-state fermentation of orange peels using microorganisms. Following a 6-day incubation period, the methanol extract obtained from the sample fermented with starter Banh men exhibited the highest concentration of total phenolic compounds (17.57 ± 0.34 mg GAE/g DW) and demonstrated the most significant DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (55.03%). The Reverse Phase High Performance Liquid Chromatography (RP-HPLC) analysis revealed that the predominant phenolic compounds in all fermented samples were flavonoid aglycones, specifically naringenin, hesperetin, and nobiletin. Conversely, in the unfermented orange peels, the major compound observed was the glycoside derivative hesperidin.

Optimizing Encapsulation: Comparative Analysis of Spray-Drying and Freeze-Drying for Sustainable Recovery of Bioactive Compounds from Citrus x paradisi L. Peels.

Spray-drying and freeze-drying are indispensable techniques for microencapsulating biologically active compounds, crucial for enhancing their bioavailability and stability while protecting them from environmental degradation. This study evaluates the effectiveness of these methods in encapsulating Citrus x paradisi L. (grapefruit) peel extract, focusing on sustainable recovery from waste peels. Key objectives included identifying optimal wall materials and assessing each encapsulation technique's impact on microencapsulation. The investigation highlighted that the choice of wall material composition significantly affects the microencapsulation's efficiency and morphological characteristics. A wall material mixture of 17 g maltodextrin, 0.5 g carboxymethylcellulose, and 2.5 g ß-cyclodextrin was optimal for spray drying. This combination resulted in a sample with a wettability time of 1170 (s), a high encapsulation efficiency of 91.41%, a solubility of 60.21%, and a low moisture content of 5.1 ± 0.255%. These properties indicate that spray-drying, particularly with this specific wall material composition, offers a durable structure and can be conducive to prolonged release. Conversely, varying the precise compositions used in the freeze-drying process yielded different results: quick wettability at 132.6 (s), a solubility profile of 61.58%, a moisture content of 5.07%, and a high encapsulation efficiency of 78.38%. The use of the lyophilization technique with this latter wall material formula resulted in a more porous structure, which may facilitate a more immediate release of encapsulated compounds and lower encapsulation efficiency.

Synthesis of Bio-Base Fluorescence Carbon Dots for Selective Detection of Tartrazine and Sunset Yellow in Food Samples.

A green, economical and simple method for the preparation of water-soluble, high-fluorescent carbon quantum dots (CQDs) has been developed via hydrothermal process using pomelo peels as carbon source. The synthesized CQDs were characterized by transmission electron microscopy (TEM), X-ray diffraction(XRD), Fourier transform infrared spectroscopy (FTIR), UV - vis absorption spectra and fluorescence spectrophotometer. The results reveal that the as-prepared C-dots were spherical shape with an average diameter of 2.64 nm and emit bright blue photoluminescence (PL) with a quantum yield of approximately 3.63%. The surface of the C-dots was rich in hydroxyl groups and presented various merits including excellent photostability, low toxicity, and satisfactory solubility. Additionally, we found that two widely used synthetic food colorants, tartrazine and sunset yellow, could result in a strong fluorescence quenching of the C-dots, The possible mechanisms are caused by different ratios of inner filter and static quenching effects. According to this property, This study attempts to establish an analytical method for the determination of tartrazine and sunset yellow using carbon quantum dots as fluorescent probe. A linear relationship was found in the range of 0-100 µM tartrazine and sunset yellow with the detection limit(3σ/k) of 0.65 nM and 1.7 nM. The relative standard deviation (RSD) was 3.5% (tartrazine) and 3.0% (sunset yellow).This observation was further successfully applied for the determination of tartrazine and sunset yellow in food samples collected from local markets, and the recovery rates of the two ranges from 79% to 117.8 and 81 -103.5%, respectively. suggesting its great potential toward food routine analysis.