Abstract

The objective of the current study is to achieve global optimization of ultrasound-assisted extraction from chicory roots using a mixed orthogonal array design. Eight conditional factors were examined in the mixed orthogonal array (L₁₆ (4³×2⁶)). The results showed that the importance of the eight factors, in decreasing order, wasethanol content, impregnation repetitions, ultrasonic input power, sonication temperature, sonication repetitions, solvent-to-solid ratio, impregnation time and sonication time. The optimum extraction conditions included a frequency of 40 kHz, an impregnation time of 24 h with two rounds of impregnation, a sonication period of 30 min and an ultrasonic input power of 400 W with two rounds of sonication.Importantly, these conditions were independent of alcohol content, solvent-to-solid ratio and sonication temperature. At frequency of 40 kHz, the alcohol content,solvent-to-solid ratio and sonication temperature were optimized in the range of 50 to 75% (v/v), 32:1 and 50°C, respectively.

Key words: Chicory roots, ultrasound-assisted extraction, mixed orthogonal design, select factors, global optimization.