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Cocoa is a rich source of health-promoting polyphenols such as flavanols. These compounds can be separated from other matrix constituents using various adsorbents or resins. Seven different macroporous resins (Amberlite XAD-2, XAD-4, XAD-7, XAD-7HP, XAD-16, Sepabeads SP207, and Diaion HP2-MG) were evaluated for their adsorption and desorption properties for the enrichment of flavonoids from an aqueous cocoa ( L.) extract. The influence of adsorption and desorption temperatures and the concentration of the desorption solvent (a hydroalcoholic solution) were investigated by static adsorption and desorption methods. The results of the resin comparison showed that the adsorbent XAD-7HP had the best adsorption characteristics, with an adsorption capacity of 39.8 mg ECE/g. XAD-7HP was found to be the most suitable adsorbent, and 70% ethanol was the best desorbing solvent, based on static experiments. In addition, the optimal conditions for the adsorption of flavonoids were obtained at a temperature of 30 °C, where equilibrium was reached after 80 min. The static adsorption process was well-described by a pseudo-second-order kinetics model, while the adsorption isotherm data were fitted well by the Freundlich isotherm model. Further dynamic adsorption and desorption characteristics were evaluated on a packed glass column, and it was shown that XAD-7HP could enrich the flavanol content by 5.03-fold, with a dry matter content of 456.05 mg/mL (as estimated by the degree of DP1-DP7 procyanidin polymers using ultra-pressure liquid chromatography).
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http://dx.doi.org/10.3390/molecules30112336 | DOI Listing |
Environ Monit Assess
September 2025
Department of Civil Engineering, Faculty of Engineering, Karpagam Academy of Higher Education, Pollachi Main Road, Eachanari Post, Coimbatore, Tamil Nadu, 641021, India.
Synthetic dyes, such as Congo red (CR), pose serious threats to human health and aquatic ecosystems because of their carcinogenicity and resistance to degradation, necessitating the development of efficient and eco-friendly remediation strategies. In this study, silver nanoparticles (AgNPs) were synthesized via a green method using Ocimum sanctum (holy basil) leaf extract and applied for CR dye removal from aqueous solutions. The adsorption process was optimized using response surface methodology (RSM) based on Box-Behnken design (BBD), evaluating the influence of key parameters including pH, AgNP dosage, initial dye concentration, contact time, and temperature.
View Article and Find Full Text PDFTalanta
September 2025
School of Chemistry, Damghan University, 36716-45667, Damghan, Iran.
Flavonoids are a major class of natural polyphenolic compounds with potent antioxidant, anti-inflammatory and anticancer properties. Among them, quercetin and catechin have been widely studied due to their significant health benefits and potent free radical scavenging activity. The efficient extraction and separation of these structurally similar antioxidants remains challenging, necessitating the development of high-performance adsorbents.
View Article and Find Full Text PDFLangmuir
September 2025
Laboratory of Electrochemistry-Corrosion, Metallurgy and Inorganic Chemistry, Faculty of Chemistry, USTHB, BP 32, 16111, Algiers, Algeria.
Azo dyes, prevalent in various industries, including textile dyeing, food, and cosmetics, pose significant environmental and health risks due to their chemical stability and toxicity. This study introduces the synthesis and application of a copper hydrogen-π-bonded benzoate framework (Cu-HBF) and its derived marigold flower-like copper oxide (MFL-CuO) in a synergetic adsorption-photocatalytic process for efficiently removing cationic azo dyes from water, specifically crystal violet (CV), methylene blue (MB), and rhodamine B (RhB). The Cu-HBF, previously available only in single crystal form, is prepared here as a crystalline powder for the first time, using a low-cost and facile procedure, allowing its application as an adsorbent and also serving as a precursor for synthesizing well-structured copper oxide (MFL-CuO).
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
September 2025
School of Chemical Engineering, State University of Campinas-Universidade Estadual de Campinas, Albert Einstein Av., 500, Campinas, SP, 13083-852, Brazil.
Bisphenol A (BPA) is a persistent organic pollutant with toxic effects on human health and ecosystems. In this study, the performance of MWCNT-OH functionalized with iron nanoparticles (MWCNT-OH@Fe) using sugarcane bagasse extract as a reducing agent (green synthesis) was evaluated for BPA adsorption. The kinetics are fast, between 10 and 20 min in the range of concentrations evaluated and the resistance to external film diffusion (external film mass transfer) identified as the rate-limiting step of the process.
View Article and Find Full Text PDFAnal Chem
September 2025
Department of Chemistry, Wuhan University, Wuhan 430072, China.
Three-dimensional printing (3DP) technology enables the flexible fabrication of integrated monolithic microextraction chips for high-throughput sample pretreatment. Meanwhile, the extraction performance of 3DP-based channels is largely limited by printer resolution and the commercially available printing materials. In this work, a 3DP array monolithic microextraction chip (AMC) was fabricated by integrating 26-array helical monolithic microextraction channels for sample pretreatment and 52-array gas valves for fluid control.
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