Effect of the essential oil of Ducrosia anethifolia (DC.) Boiss. and Teucrium polium L. on physicochemical, sensory, and microbial characteristics of probiotic yogurt during storage time

Today, use of functional food, such as probiotic products, is important due to their health benefits against diseases. In this study, the essential oil of Ducrosia anethifolia and Teucrium polium (DAEO and TPEO, respectively) were added to probiotic yogurt (Lactobacillus acidophilus and Bifidobacterium bifidum bacteria) to investigate their effects on the survival of probiotic bacteria during 21 days and assess its various properties. The results showed upon increasing the concentration of DAEO and TPEO, the value of acidity and viscosity of yogurt treatments increased, and the pH and syneresis showed a decreasing trend (P<0.05). The survivability of the investigated probiotic bacteria demonstrated a decreased trend during storage in all treatments, but finally, the number of probiotic bacteria in all treatments was significantly higher than that of the control samples. Based on the results of all tests, the addition of 0.03% of DAEO is the best way to realize the goals of the research.