Enhanced extraction of caffeine from guarana seeds using aqueous solutions of ionic liquids
authors Claudio, AFM; Ferreira, AM; Freire, MG; Coutinho, JAP
nationality International
journal GREEN CHEMISTRY
keywords SUPERCRITICAL CARBON-DIOXIDE; FIBER WASTES; TEA STALK; SEPARATION; ALKALOIDS; SOLUBILITY; PAULLINIA; STACKING; PRODUCTS; ETHANOL
abstract The extraction of caffeine from bioresources using more benign and cost-effective processes is of fundamental relevance towards the finding of alternative (bio) pesticides. Classically, the best attempts to extract caffeine from biomass have resulted in low efficiency and in a large consumption of hazardous organic solvents and/or energy requirements. Here, we report an enhanced and selective extraction of caffeine from guarana (Paullinia cupana, Sapindaceae) seeds using aqueous solutions of ionic liquids. Several ionic liquids composed of imidazolium or pyrrolidinium cations combined with the chloride, acetate and tosylate anions were investigated. Furthermore, the effect of the cation alkyl side chain length and the presence of functionalized groups were also addressed. Additional conditions such as the ionic liquid concentration, the contact time, the solid-liquid ratio and temperature were further optimized by a response surface methodology. Outstanding extraction yields (up to 9 wt% of caffeine per guarana dry weight) were obtained at a moderate temperature and in a short-time. The recyclability and reusability of the ionic liquids were also confirmed. For the first time it is shown that aqueous solutions of ionic liquids are superior alternatives for the solid-liquid extraction of caffeine from biomass samples and, as a result, the development of an ionic-liquid-based process is straightforwardly envisaged.
publisher ROYAL SOC CHEMISTRY
issn 1463-9262
year published 2013
volume 15
issue 7
beginning page 2002
ending page 2010
digital object identifier (doi) 10.1039/c3gc40437d
web of science category Chemistry, Multidisciplinary; GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY
subject category Chemistry; Science & Technology - Other Topics
unique article identifier WOS:000320781200030

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