RESUMEN
In this study the effect of gelan, xanthan and quince seed gum (QSG) on stability, probiotic viability and qualitative properties of Doogh using response surface methodology was determined. Three gums were used at three levels of 0, 0.25 and 0.5%. The results showed that the effect of QSG on viscosity and serum separation was significant (P < 0.05). The effect of QSG on viability of B. bifidum was significant (P < 0.05). Sensory evaluation showed that effect of using of QSG was significant and the score of taste, odor and overall acceptance increased by increasing of concentration of QSG. At the optimum point, the stability, viscosity pH, probiotic load and overall acceptance were 92.24%, 11.852 mPa s, 3.87, 8.37 log cfu/mL and 4.42, respectively. Using of combination of gums at the optimal concentration prevented phase separation and maintained the probiotic viability of Doogh. Therefore, the optimization of formulation can be used for production of stabilized probiotic Doogh in dairy industry.