Abstract

Plant-derived compounds used as alternatives to chemical preservatives have been extensively researched for use as natural medical ingredients or food preservatives. Conditions for the ultrasound-assisted extraction (UAE) of chicory (Cichorium intybus) root (including type of solvent, impregnation time, number of sonication steps and ultrasonic power) were optimized to determine the best extract antibacterial activity by using orthogonal matrix design [L₁₆ (4⁵)]. The combination of 70% ethanol v/v, a 36 h impregnation time, three sonication rounds and 300 W ultrasonic power input provided the best antimicrobial activity results. Our results demonstrate that solvent composition has the largest effect on antimicrobial activity. Several extracts demonstrated antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacillus thuringiensis andSalmonella typhi, and all extracts exhibited weak activity against Bacillus subtilis. To our knowledge, these results represent the first example of ultrasound-assisted chicory extracts aimed at increasing its potential for use in food industry.

Key words: Cichorium intybus, antibacterial, ultrasound-assistant extract, optimal conditions, orthogonal matrix design.