EXTRACTION OPTIMIZATION OF TRADESCANTIA SPATHACEA SW. LEAF CRUDE EXTRACT AND ANTHOCYANIN CONTENT

Abstract

Considering both the health and energy areas where anthocyanins have been revealing their real and potential applications, research on their extraction optimization methods is a priority. Conditions to achieve the highest mass of crude extract from Tradescantia spathacea leaves with the highest absorbance (A) in the region of 500 - 540 nm linked with anthocyanins, were investigated through a Box-Behnken design and response surface methodology. Independent variables involved in the Box-Behnken design were solvent (ethanol) concentration (30, 50, 70 % v/v), solvent/fresh leaf ratio (1.67:1, 2.34:1; 3:1 v/w) and extraction temperature (30, 50, 70 °C). Dependent (response) variables were crude extract amount and the extract with the maximum A in the region of 500-540 nm. Experimental values of A 500 - 540 nm were 0.3562 and 0.7558; crude extract mass ranged between 0.285 g and 0.7157 g, corresponding to a yield between 144 to 347 mg dried extract per g of dried leaf. Using a solvent/fresh leaf ratio of 3:1 v/w, 70 °C, 65 % ethanol, the highest values of both crude extract mass and A 500 - 540 nm were obtained.

Keywords

• extraction
• health and energy applications
• natural red pigments