Investigation of the Effect of Adding Bahar Narang (Citrus aurantium) Extract on Chemical, Sensory and Biological Properties of Doogh

In this study, the effect of adding Bahar narang (Citrus aurantium) (400 ppm) and encapsulated Bahar narang extract (2000 ppm) and storage time (0, 7, 14, 21 and 28 days) on chemical properties (pH, acidity, and dry matter) and total phenolic compounds, microbial and sensory properties (flavor and overall acceptance) of doogh were evaluated. The results showed that the amount of free and encapsulated Bahar narang extract had a significant effect on pH, acidity, phenolic compounds and the total count of mold and yeast (P< 0.05). As the increased the amount of free and encapsulated Bahar narang extract, the pH and phenolic compounds increased and the amount of acidity, mold and yeast decreased significantly (P> 0.05). Storage time also had a significant effect on all measurement factors (P< 0.05). Over time, the amount of phenolic compounds in the control sample and the sample containing free extract decreased and the count of mold and yeast in the control sample and treatment containing free extract increased, but in the sample of doogh containing encapsulated extract no mold and yeast were observed until the 21 day of storage. Phenolic compounds were also preserved until the last day of storage. The results of statistical analysis of sensory evaluation of doogh samples also showed that with the addition of Bahar narang extract, the flavor score and overall acceptance increased (P <0.05). The results indicate that the addition of Bahar narang extract increases the shelf life of doogh and improves its sensory properties.