Antimicrobial and Antioxidant Activities of Betel Oil

Abstract

Betel oil has been studied for its antimicrobial and antioxidant activities against ten pathogenic and spoilage bacteria and three strains of yeast using an agar well diffusion assay and against oxidative bleaching using a β-carotene agar well diffusion assay, respectively. The minimum inhibitory concentration (MIC) and minimum oxidative bleaching inhibitory concentration (MOBIC) of betel oil were determined using an agar dilution method. At the concentration of 50 µL mL^-1, betel oil showed a zone of inhibition, ranging from 9.15 to 17.30 mm in diameter. The MICs of betel oil in a range of 12.5-100 µL mL^-1 could inhibit the growth of all test microorganisms except Pseudomonas aeruginosa, which was not sensitive to this oil even at the highest concentration (200 µL mL^-1). The most sensitive bacteria to betel oil were Listeria monocytogenes and Salmonella Enteritidis. Betel oil (100 µL mL-1) also revealed ability to inhibit the oxidation of b-carotene, yielding a yellow zone surrounding the well with a 8.40 mm in diameter. The MOBIC of betel oil was 100 µL mL^-1. Betel oil might have a potential application in controlled and released food packaging technology as antimicrobial and antioxidant agents.