Synthesis and Optimization of biosorbent using jabuticaba peel (Myrciaria cauliflora) for anthocyanin recovery through adsorption

This study presents the use of jabuticaba peel to create a biosorbent material for recovering cyanidin-3-glucoside (C3G), a valuable compound in anthocyanin-rich extracts. This approach tackles waste management, promotes a circular economy, and offers a sustainable alternative to traditional methods. The biosorbents were synthesized through a chemical activation using three different solvents: H₃PO₄, HNO₃, and KOH. Sample characterization was conducted through various techniques, providing a thorough and multi-faceted understanding of the material properties. The morphological results showed the development of rich porous structures and increased carbon concentrations after activation, enhancing the adsorption capacity of the synthesized materials derived from jaboticaba peel. The H₃PO₄-activated biosorbent outperformed commercial adsorbents. Granulometric and concentration studies identified optimal conditions, and colorimetric analysis confirmed effective C3G removal. Kinetic studies indicated an adsorption process reaching equilibrium within 9.0 h. The Avrami model suggested a complex adsorption mechanism and intraparticle diffusion, which revealed a two-step process involving external mass transfer and internal diffusion. Adsorption isotherms at different temperatures fit the Langmuir model, indicating favorable adsorption behavior. The thermodynamic analysis confirmed the viability of jabuticaba peel biosorbents for eco-friendly C3G removal due to spontaneous, endothermic adsorption processes. The reuse study demonstrated that the biosorbent maintained its adsorption capacity up to the fifth cycle. Additionally, the adsorption mechanism of C3G on H₃PO₄-activated biosorbent was identified, emphasizing cation-π interaction, pore filling, electrostatic attraction, van der Waals forces, hydrogen bonds, and π-π interactions at pH 2. This revealed a physisorption process with diverse intermolecular forces. This study further supports ecological waste management and the creation of economical biosorbents for anthocyanin recovery, valuable compounds applicable in pharmaceuticals, food, and nutraceutical industries.