Capparis spinosa ethanolic extract: phenol, flavonoid, antioxidant potential and antibacterial activity on Enterobacter aerogenesis, Escherichia coli, Staphylococcus aureus and Listeria monocytogenes

Plants have always been the main source of food and medicine for humans. Plant extracts have been considered in the food industry as antimicrobials, flavor enhancers, preservatives, and nutrients. Plant extracts are an excellent candidate for the replacement of synthetic compounds that have toxic and carcinogenic effects. In this study, ethanolic extract of Capparis spinosa was extracted by maceration method and the content of total phenols (by Folin Ciocalteu method), total flavonoids (by aluminum chloride colorimetry), antioxidant activity (by DPPH and ABTS free radical scavenging methods), and its antimicrobial effect (by disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum bactericidal concentration) against Enterobacter aerogenesis, Escherichia coli, Staphylococcus aureus and Listeria monocytogenes, were evaluated. The total phenols and total flavonoids of the extract were 40.28 mg GAE/g and 5.20 mg QE/g, respectively. The antioxidant activity of ethanolic extract based on inhibition of free radicals DPPH and ABTS was 52.73 and 58.62%, respectively. The antimicrobial effect of the extract was dependent on its concentration and bacterial type; increasing the concentration of the extract caused a significant increase in the diameter of the growth inhibition halo in disk diffusion agar and well diffusion agar tests. In addition, Gram-positive bacteria (S. aureus and L. monocytogenes) were more sensitive to the extract than Gram-negative strains (E. aerogenesis and E. coli). Also, S. aureus with a minimum inhibitory concentration of 4 mg/ml and a minimum bactericidal concentration of 512 mg/ml was the most sensitive species to the ethanolic extract of C. spinosa. The results of the present research show that the ethanolic extract of Capparis spinosa can be used as a natural additive in various food products.