Antimicrobial activity of Satureja Khuzestanica Jamzad and Satureja bachtiarica Bunge essential oils against Shigella flexneri and Escherichia coli in table cream containing Lactobacillus plantarum LU5

Abstract

The essential oils (EOs) from Marzeh khuzestani (Satureja Khuzestanica Jamzad) and Marzeh bakhtiari (Satureja bachtiarica Bunge) were analyzed and their antibacterial activities on Shigella flexneri and Escherichia coli in probiotic table cream containing Lactobacillus plantarum LU5 were evaluated. Carvacrol (86.5%) was the main component of Marzeh khuzestani, but thymol (33.5%), carvacrol (14.2%), borneol (13.4%), and linalool (11.5%) were the major constituents of Marzeh Bakhtiari EOs. Marzeh khuzestani exhibited the highest antibacterial/bactericidal activity on the tested bacteria. EOs combination showed no interaction on the L. plantarum but a synergism effect to inhibit the pathogen strains observed. Agar diffusion assay showed the highest inhibitory effect on S. flexneri (32.7 mm), E. coli (28.4 mm), and L. plantarum (24.7 mm) for the combination 2:1 Marzeh khuzestani:Marzeh Bakhtiari (p ≤ .05). The antibacterial activity of mixture of EOs in creams was evaluated and the sample contained of 1%k + 1%b showed the highest antibacterial activity after day 10 of storage (by lowering the number of E. coli, S. flexneri, and L. plantarum to 2.3, 1.9, and 1.4 log CFU/g compared to control sample). Overall acceptability of creams slightly decreased by the increase in EOs addition and the highest acceptability score of 7.9 observed for the sample contained 0.5%k + 0.5%b EOs. However, all treatments exhibited a high acceptance level that it confirms that the addition of EOs mixture had no effect on the sensorial attributes of the creams. The combination of tested EOs can be used as an antimicrobial agent in probiotic food products containing L. plantarum.

Keywords

• antibacterial assay
• essential oils
• gas chromatography
• shelf life
• table cream