Investigation and comparison of effects of natural composition inhibitory Staphylococcus aureus in industrial doogh samples with response surface method (RSM)

Abstract

In recent years, the uses of natural antimicrobial compounds, including extracts and herbal powders as preservative compound of the food are increasingly popular. The aim of the study was to evaluate antimicrobial effect of extract and powder of lamiaceae plants (thymus vulgaris L., Mentha spp. and Ziziphora tenuir L.) over prevention of pathogenic bacteria (Staphylococcus aureus) growth by examining industrial Doogh samples. For this purpose, three extracts contained (0, 0.075, 0.15 v/v) and powder contained (0, 0.075, 0.15 v/v) were prepared. Bacterial population decrease or survival in doogh samples were examined according to Staphylococcus pure strains in a 24 hours time within separate rounds by measuring the kinetics of bactericidal effects, using response surface design. Analysis Results in the inhibition effects of natural antibiotic agent in the Doogh samples revealed that: the powder of Lamiaceae family have greater effects on decreasing population of Staphylococcus than extracts. The best amounts of powder for decreasing pathogenic bacterial population were as flowing, Thymus 0.09 (v/v), Mentha 0.06 (v/v), and Ziziphora 0.14(v/v). In these circumstances greatest reduction of Staphylococcus population in 24 h is 1.98 Log/ml.

Keywords

• natural inhibitor compounds
• thymus vulgaris l
• mentha spp. and ziziphora tenuir l
• staphylococcus aureus
• industrial doogh