Skip to Content
Merck
  • Highly efficient extraction of anthocyanins from grape skin using deep eutectic solvents as green and tunable media.

Highly efficient extraction of anthocyanins from grape skin using deep eutectic solvents as green and tunable media.

Archives of pharmacal research (2015-11-05)
Kyung Min Jeong, Jing Zhao, Yan Jin, Seong Rok Heo, Se Young Han, Da Eun Yoo, Jeongmi Lee
ABSTRACT

Deep eutectic solvents (DESs) were investigated as tunable, environmentally benign, yet superior extraction media to enhance the extraction of anthocyanins from grape skin, which is usually discarded as waste. Ten DESs containing choline chloride as hydrogen bond acceptor combined with different hydrogen bond donors were screened for high extraction efficiencies based on the anthocyanin extraction yields. As a result, citric acid, D-(+)-maltose, and fructose were selected as the effective DES components, and the newly designed DES, CM-6 that is composed of citric acid and D-(+)-maltose at 4:1 molar ratio, exhibited significantly higher levels of anthocyanin extraction yields than conventional extraction solvents such as 80% aqueous methanol. The final extraction method was established based on the ultrasound-assisted extraction under conditions optimized using response surface methodology. Its extraction yields were double or even higher than those of conventional methods that are time-consuming and use volatile organic solvents. Our method is truly a green method for anthocyanin extraction with great extraction efficiency using a minimal amount of time and solvent. Moreover, this study suggested that grape skin, the by-products of grape juice processing, could serve as a valuable source for safe, natural colorants or antioxidants by use of the eco-friendly extraction solvent, CM-6.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
DL-Malic acid, 99%
Supelco
Phenol solution, certified reference material, 500 μg/mL in methanol
Supelco
Phenol solution, 5000 μg/mL in methanol, certified reference material
Sigma-Aldrich
Ethyl alcohol, Pure, 200 proof, anhydrous, ≥99.5%
Sigma-Aldrich
Citric acid, ACS reagent, ≥99.5%
Sigma-Aldrich
Glycerol, FCC, FG
Sigma-Aldrich
Phenol, unstabilized, ReagentPlus®, ≥99%
Sigma-Aldrich
Phenol, ACS reagent, ≥99.0%
Sigma-Aldrich
Phenol, puriss., meets analytical specification of Ph. Eur., BP, USP, 99.5-100.5% (GC)
Sigma-Aldrich
Choline chloride, BioUltra, ≥99.0% (AT)
Sigma-Aldrich
Sucrose, BioUltra, for molecular biology, ≥99.5% (HPLC)
Sigma-Aldrich
5α-Androstan-17β-ol-3-one, purum, ≥99.0% (TLC)
Sigma-Aldrich
DL-Malic acid, meets analytical specification of FCC, E296, 99-100.5% (alkalimetric)
Sigma-Aldrich
Phenol, puriss., ≥99.5% (GC), meets analytical specification of Ph. Eur., BP, USP, crystalline (detached)
Sigma-Aldrich
Sucrose, puriss., meets analytical specification of Ph. Eur., BP, NF
Sigma-Aldrich
Phenol, ≥96.0% (calc. on dry substance, T)
Sigma-Aldrich
Phenol, unstabilized, purified by redistillation, ≥99%
Sigma-Aldrich
Sodium carbonate-12C, 99.9 atom % 12C
Sigma-Aldrich
Ethyl alcohol, Pure, 190 proof, ACS spectrophotometric grade, 95.0%
Sigma-Aldrich
Citric acid, ≥99.5%, FCC, FG
Sigma-Aldrich
Hydrogen chloride, ReagentPlus®, ≥99%
Sigma-Aldrich
Citric acid, BioUltra, anhydrous, ≥99.5% (T)
Sigma-Aldrich
Diethylstilbestrol, mixture of cis and trans, 97%
Sigma-Aldrich
Formic acid, ≥95%, FCC, FG
Sigma-Aldrich
2-Hydroxybutyric acid sodium salt, 97%
Sigma-Aldrich
Phenol, ≥99%
Sigma-Aldrich
Phenol, BioUltra, for molecular biology, TE-saturated, ~73% (T)
Sigma-Aldrich
Phenol, puriss. p.a., ACS reagent, reag. Ph. Eur., 99.0-100.5%
Sigma-Aldrich
DL-Malic acid, ReagentPlus®, ≥99%
Sigma-Aldrich
Sucrose, meets USP testing specifications