Advisor(s)
Abstract(s)
The extraction of phenolic compounds from walnut leaves (Juglans regia L.) was optimized using heat-assisted
extraction and deep eutectic solvents based on choline chloride and carboxylic acids. A preliminary solvent
screening was performed using a selected group of carboxylic acids as hydrogen bond donors, showing that the
highest extraction yield of phenolic compounds was obtained using choline chloride mixtures with butyric or
phenylpropionic acid at a mole ratio 1:2, with 20% of water (w/w). The extraction conditions (time, temperature
and water proportion) were then optimized by an experimental design, assisted by response surface methodology.
To evaluate the response, the three most abundant compounds identified by HPLC (neochlorogenic acid,
quercetin 3-O-glucoside and quercetin O-pentoside) were quantified. Additionally, the solid/liquid ratio effect at
the optimal conditions, in dose-response format, was studied in view of its upscale, not showing any significant
decrease until 140 g/L. The results here presented provide valuable information towards the design of a process
in a pre-industrial form for the extraction of phenolic compounds from J. regia leaves using deep eutectic solvents.
Description
Keywords
Deep eutectic solvents Heat-assisted extraction Juglans regia L. Phenolic compounds Response surface methodology
Citation
Vieira, Vanessa; Prieto, Miguel A.; Barros, Lillian; Coutinho, João A.P.; Ferreira, Isabel C.F.R.; Ferreira, Olga (2018). Enhanced extraction of phenolic compounds using choline chloride based deep eutectic solvents from Juglans regia L.. Industrial Crops and Products. ISSN 0926-6690. 115, p. 261-271