Design of optimal solvent for extraction of bio-active ingredients from mulberry leaves

A method of designing solvents for the optimal extraction of bio-active ingredients from natural resources was developed using an alcohol-water binary solvent. The target bio-active ingredient of polyphenols, anti-oxidation and anti-tyrosinase ingredients exhibited different dependency of extraction efficiency on the alcohol species (methanol, ethanol, n-propanol and i-propanol) and composition of binary solvent. Using the solubility parameter, the extraction efficiency of the bio-active ingredients was correlated with the solvent polarity. As a result, the optimal solvent polarities for the extraction of polyphenols, anti-oxidation and anti-tyrosinase ingredients were predicted as 38.5, 37.33, and 33.0 [MPa1/2], respectively. These predictions also agreed well with the optimal solvent conditions of the water-alcohol mixtures depending on the alcohol species and composition. Plus, the correlation was confirmed with model solvents designed using other solvent species, including acetone and ethylene glycol. (C) 2007 Elsevier B.V. All rights reserved.