Antibacterial activity of liquid smoke and Pistacia atlantica Subsp. Kurdica on Lactobacillus bulgaricus
Subject Areas : Aquatic ProductsGhazal Rahimzadeh 1 , Asad Rokhzadi 2 , Samira Bahramian 3
1 - Department of Food Science and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 - Department of Agronomy, College of Agriculture, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran
3 - Department of Food Science and Technology, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran
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Abstract :
Abstract Smoked Doogh and Doogh flavored with Pistacia atlantica Subsp. Kurdica essential oil (mastic resin) are popular products in Kurdistan region. Anti-pathogenic effects of these essential oils have been shown in many studies. However, their effects on lactic acid bacteria in dairy products have never been investigated. Therefore, the aim of this study was to evaluate the effect of these essential oils on Lactobacillus bulgaricus. After isolation and purification of L. bulgaricus from Doogh, Mueller Hinton Agar was used for Disk Diffusion method to assess the susceptibility of the bacteria in different concentrations of the essential oils (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5 and 100%). The minimum inhibitory concentration for mastic resin and liquid smoke were 0.1% and 0.9 %, and the zone of inhibition was 11 and 6.5 mm, respectively. Furthermore, the inhibition zone diameters increased with the increasing in essential oil’s concentrations. According to the result of this study, L. bulgaricus is susceptible to mastic resin essential oil. Therefore, it will be recommended that using this essential oil should be restricted in dairy products. Furthermore, there is no problem in using it in fermented products containing L. bulgaricus in less than 0.9% concentrations of liquid smoke. At whole, the effect of essential oils on lactic acid bacteria should be investigated, before using them in dairy products.