Extraction of bioactive compounds of lemongrass, antioxidant activity and evaluation of antimicrobial activity in fresh chicken sausage

Abstract

The aim of this work was to determine the best extraction condition of bioactive compounds from lemongrass (Cymbopogon citratus), using the conventional method and ultrasonic assisted extraction, varying the temperature, in order to evaluate the antioxidant activity and the antimicrobial activity of the extract with higher antioxidant power in fresh chicken sausages during the storage period. The extracts were obtained by the conventional method (solvent extraction) and by ultrasound assisted extraction, varying the temperature (20°C, 40°C and 60°C). Phenolic compounds, total flavonoids and antioxidant activity were measured by the DPPH, FRAP, ORAC methods. Conventional extraction and ultrasound methods influenced the phenolic and total flavonoid content at all tested temperatures. Conventional and ultrasonic methods did not influence the IC50 at temperatures of 40°C and 60°C. The antioxidant activity by the DPPH method and by the FRAP method was superior in the conventional method at the temperature of 60°C, however by the ORAC method the best results were in the extraction by ultrasound. The results demonstrate that the conventional extraction at 60ºC was better to obtain extracts of lemongrass with greater amount of bioactive compounds. The antimicrobial capacity evaluated in sausage of fresh chicken showed that in the concentration of 1.0% of the extract protected the product as the growth of mesophilic aerobes and against the growth of psychotrophic bacteria. Lemongrass can be considered as a natural alternative to obtain extracts rich in bioactive compounds, with antioxidant activity and high antimicrobial capacity.