Influence of microencapsulated wild watercress (Nasturtium officinale L.) and dill (Anethum graveolens L.) essential oils on the physicochemical, microbial, rheological and sensory properties of probiotic Doogh

In the first step of this study, Anethum graveolens and Nasturtium officinale essential oils prepared with Clevenger apparatus and then, essential oils ingredients evaluated by GC-Mass. Minimum Inhibitory (MIC) and Minimum Bactericidal Concentration (MBC) and antioxidant activity of essential oils were evaluated at concentrations of 350, 400, 500, 600 and 650 mg/L during 60 days. Then, encapsulated essential oils of A. graveolens and N. officinale in the mentioned concentrations by maltodextrin and coacervation methods to evaluate morphology and particle size distribution. Finally, to achieve the optimal concentration of essential oils in order to further preserve the probiotic population of Bifidobacterium lactis, the viability of this bacterium in doogh was evaluated for 21 days. In the second step of the study, the effect of adding essential oils on optimal concentration to the product investigated according to dry matter content, pH, acidity, serum separation rate, rheology and sensory evaluation. The results showed the essential oils have high terpene and phenolic content, which caused proper antioxidant and antimicrobial activity. The viscosity, consistency and acidity of the final product increased on the other hand, pH and serum separation rate decreased significantly. Considering the results of sensory evaluation and lack of any negative effects at optilam concentrations of 400 mg/L and 500 mg/L for A. graveolens and N. officinale essential oils, respectively, the possibility of its industrial application can be examined.