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 psychrotrophic bacteria. Lemongrass can be considered as a natural alternative to obtain extracts rich in bioactive compounds, with antioxidant activity and high antimicrobial capacity

Phenolic compounds, antimicrobial activity, cytotoxicity, and identification of phytochemicals present in Inga marginata Willd seeds

Brazil has an invaluable source of plants and fruits rich in phenolic compounds important to health, some of which have yet to be discovered. Inga marginata Willd is a fruit that can be found throughout Brazil, and its seeds are rich in phenolic compounds and antimicrobial activity, thus making their extraction and characterization highly relevant. This study aimed to determine the total phenolic compounds, antioxidant capacity, antibacterial and antifungal activities, cytotoxicity evaluation, and characterize the phytochemical compounds present in the extract. The results indicated that extraction by agitation at 30 ºC obtained the highest yield of total phenolic compounds (48.23 mg GAE g-1), antioxidant capacity (40.34 mg TEAC g-1), and IC50 (2.60 mg mL-1). The extracts at 30 and 60 ºC inhibited all microorganisms tested, and the temperature of 30 ºC acted as a bactericide and fungicide at low concentrations. Ten phytochemical compounds were found, mainly being antioxidants and antimicrobials. The cytotoxicity assays showed that Inga marginata seeds do not present cellular cytotoxicity up to the concentration of 250 µg mL-1, maintaining cell viability above 90%

Ultrasonic assisted extraction to obtain bioactive, antioxidant and antimicrobial compounds from marcela

<div><p>ABSTRACT: The aim of this study was to evaluate the effect of extraction conditions on bioactive compounds, as well as on antioxidant activity, and the antimicrobial activity of the extracts with the highest antioxidant characteristics. The extracts were obtained by conventional method and ultrasound-assisted extraction at various temperatures (20°C, 40°C and 60°C). Total phenolics, total flavonoids, antimicrobial activity and antioxidant activity were quantified by the methods of DPPH, FRAP, and ORAC, respectively. The conventional extraction method and ultrasound method influenced the phenolic content at all the tested temperatures. Flavonoids were not influenced by extraction methods. The antioxidant activity (DPPH) was highest in the ultrasonic method at temperatures of 40°C and 60°C; however, in the case of the FRAP method the best results were for the conventional extraction method. The conventional and ultrasonic methods did not influence the IC50 at temperatures of 20°C and 40°C, but using ORAC the antioxidant activity was influenced by the methods at all temperatures. The extract obtained at 60°C by the ultrasound method had high antimicrobial action in relation to the strains of Salmonella sp., Escherichia coli, and Staphylococcus aureus. Extraction ultrasonic-assisted can be considered adequate to obtain extracts of marcela, which are rich in bioactive compounds with high antioxidant activity.</p></div