Solvent optimization for caffeine and tannic acid extraction from Guarana seed: Insights from molecular dynamics simulations

Guarana seeds are a rich source of bioactive compounds, particularly caffeine and tannic acid, which have significant applications in the food and pharmaceutical industries. To extract these valuable compounds from the guarana seeds, solvent extraction methods are used. Molecular dynamics (MD) simulations are employed to investigate the interaction of Guarana seed extract with three different solvents namely ethanol, ethyl acetate and Choline chloride-glycerol as deep eutectic solvent (DES) varying the molar ratio. The bonded and non-bonded interactions are computed to perform the MD simulations. The optimized potentials for liquid simulations force field are used to compute these interactions. The study examines the Radial Distribution Function (RDF) and hydrogen bonds to elucidate structural arrangement and intermolecular interactions respectively. RDF reveals that the interaction of caffeine with ethanol is strongest hence it is the best suitable solvent for its extraction. Mean Square Displacement analysis offers insights into transport properties, particularly diffusion of molecules in solvents. Primarily subdiffusive nature for the mobility of functional moieties of Guarana seed components are observed in solvents. The comparison of diffusive regimes further reveals the preferential extraction of caffeine and tannic acid over the minor compounds using ethanol. The selective separation leads their essential applications in the food industry.