Effects of ionic liquids and pulsed electric fields on the extraction of antioxidants from green asparagus roots

Abstract

Asparagus officinalis root (AR) contains valuable bioactive compounds that have beneficial health properties. The aim of this study was to optimize the extraction of polyphenols and flavonoids in green AR using two novel technologies; pulsed electric field (PEF) and ionic liquids (IL). Further, the antioxidant activity of the obtained extracts was determined. The total polyphenol content, total flavonoid content (TFC), and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl, oxygen radical absorbance capacity and Ferric reducing/antioxidant power assays) were determined. The PEF conditions (PEF strength of 1.6 kV/ cm, frequency of 200 Hz and pulse width of 20 µs) resulted in a higher extraction yield as compared to conventional solvent extraction, but had lower antioxidant activities. The optimal conditions for IL extraction were by using 0.5% 1-butyl-3-methylimidazolium chloride at a solid: liquid (S:L) ratio of 1:10 for four min. The IL extraction resulted in a total of 122 mg RE/ mL TFC which was 70 to 80 folds more than the TFC obtained by PEF. The IL extracts had higher TFC and antioxidant activity than PEF, but the safety of the ILs need further research.

Sustainable Food Systems: The Case of Functional Compounds towards the Development of Clean Label Food Products

“…However, the authors highlighted the possible negative effect of the high temperatures (110–230 °C) employed to the final extracts’ overall quality. Symes et al [ 72 ] evaluated the extraction of antioxidants from asparagus roots using either ILs or PEF or conventional solvent extraction. Their results indicated that the extraction capacity of ILs was 70 times higher in comparison to that of PEF.…”

Ionic liquids revolutionizing biomedicine: recent advances and emerging opportunities

“…6B). In addition to the two IL-based external field assisted extraction methods, other IL-assisted extraction methods exist, such as IL-heating extraction, 194 IL-based pulsed electric fields 195 and IL-based pressurized liquid extraction. 196 However, these methods may have drawbacks, such as increased energy requirements or the need for expensive and high-security equipment.…”

Effect of Water-Soluble Coronatine on Production of Paclitaxel in a Plant Cell Culture with Water-immiscible 1-Butyl-1-methylpyrrolidinium Bis(trifluoromethanesulfonyl)imide

“…Ionic liquids have been getting attention as alternatives to conventional organic solvents for the extraction of biologically active compounds from biomass [7][8][9][10][11][12][13][14]. Symes et al described that significant extraction of antioxidants from green asparagus root with an ionic liquid, 1-butyl-3-methylimidazolium chloride [15]. The enhanced production amount of paclitaxel in two-phase culture system with in situ extraction by a hydrophobic ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (P14TFSI, Figure 1) was previously reported [16].…”