بررسی ویژگی‌های فیزیکو شیمیایی، میکروبی، رئولوژیکی و حسی دوغ حاوی عصاره و پودر گیاه ملیس

The aims of this study were evaluating the effect of Mellis herb (Melissa officinalis) powder and extract addition on the microbiological, chemical, rheological and sensorial attributes of pasteurized Doogh. In this study, 72 different Doogh samples were produced with Mellis extract and powder. On days 1, 10, 20, and 30, the physicochemical, microbial, rheological and sensory properties of Doogh samples were measured with three replications. pH, acidity, dry matter and SNF of Doogh samples containing Mellis powder and extract were significantly different (p<0.05). In the case of all of parameters the mean value of powder were greater than extract and there were no significant differences in syneresis and viscosity of Doogh samples. The rheological pattern of Doogh samples were as pseudoplastic fluid. In the case of sensorial properties, the flavor of mellis containing Doogh samples with powder and extract were not significantly different, but the about the texture, appearance and general acceptability, the extract and powder were significantly different and the scores of taste, texture, appearance and general acceptability of extract was higher than powder. Mellis addition inhibited the overall growth of moulds and yeasts until the 20th day. In the case of syneresis, at the first days, extract containing samples had lower syneresis but it increases with acidity development during the shelflife. As a result, using Mellis in Doogh production have beneficial effect on chemical, microbiological and sensorial properties of the product.