Phytochemicals of ethanolic extract and essential oil of Persicaria hydropiper and their potential as antibacterial agents for food packaging polylactic acid film

This study aims to determine phytochemicals and antibacterial activity of ethanolic extract and essential oil ofPersicaria hydropiper, and their potential as antibacterial agents in polylactic acid (PLA) film. The yield of ethanolic extract and essential oil were 11.02 and 0.70%, respectively. Chlorogenic acid, ferulic acid, rutin, myricetin and quercetin were detected as major components in theP. hydropiperethanolic extract, while dodecanal, caryophyllene, caryophyllene oxide, decanal, α‐caryophyllene, citronellol, heptadecanal, linalool and phytol were detected in theP. hydropiperessential oil. Based on the disc diffusion assay, both ethanolic extract and essential oil ofP. hydropiperpossessed antibacterial activity against bacteriaStaphylococcus aureusonly at different concentrations, with minimum inhibitory concentration values: 0.625 and 5 mg/ml, respectively; and minimum bactericidal concentration values: 5 and 40 mg/ml, respectively. However, they found to show antibacterial activity against three bacteriaS. aureus,Escherichia coliandSalmonella Typhimuriumat different concentrations and time using time‐kill kinetics assay. Incorporation of ethanolic extract and essential oil in PLA film also exhibited an antibacterial effect againstS. aureus. Our findings confirmed the potential use of bothP. hydropiperethanolic extract and essential oil as antibacterial agents in biodegradable PLA film.