The Effectiveness of Alcoholic Rosa Damascene Extract on Lactobacilus Acidophilus and bifidobacterium lactis Probiotic Bacteria Survival in Doogh

In this research, the effect of Rose alcoholic extract on the viability of probiotic bacteria Lactobacillus acidophilus (La-5) and Bifidobacterium lactis (Bb-12) in Doogh was studied. Probiotic bacteria Bifidobacterium bifidum and Lactobacillus acidophilus were inoculated into Doogh without Rose alcoholic extract (control) and containing Rose alcoholic extract (1% and 2%). Doogh produced during 4 weeks of storage in a refrigerator at 4° C during a week was investigated for microbial count, pH changes, acidity and survival during the shelf life and the organoleptic characteristics of the product were studied. The results of the statistical analysis indicated that the difference in survival percentage of La-5 and Bb-12 between the ordinary Doogh and the Doogh containing Rose alcoholic extract was significant (p≥0.05). Regarding taste, the results of this study showed that there is a significant difference between the types of Doogh in terms of taste (p<0.05). The study of organoleptic characteristics of Doogh containing Rose alcoholic extract showed that the flavor of this Doogh was improved compared to ordinary Doogh. The pH decreased during the shelf life and the acidity increased slightly. The highest and lowest levels of pH were respectively observed for samples containing 1% and 2% extract. Also, the effect of extract amount on acidity showed that the highest and lowest levels of acidity were in the samples containing 2% and 1% extract, respectively. Therefore, the production and consumption of Doogh containing Rose extract by maintaining organoleptic characteristics together with probiotic bacteria as a pragmatic food product are recommended.