Due to the high nutritional value, dairy products especially milk are widely consumed by people which caused manufacture to produce various products. Milk-juice beverage is a type of acidified milk drink which has been produced from mixture of milk, fruit juice, sugar and stabilizer as necessary. Barberry juice is considered one of the most delicious drinks that Iranian people consume it in the summer as a blood purifier. This juice contains organic acids (malic acid and tartaric acid); phenolic compounds and anthocyanin as well as enzymes like phenolase, poly phenolase and glycosidase. Whey separation is a common problem in production and storage of acidified milk drinks (AMDs) which is due to the casein instability and sedimentation at low pH (4.6?). To prevent or reduce protein aggregation, different stabilizers are used. In this study, pectin, carboxymethyl cellulose (CMC) and their mixture (at 50:50 ratio) at concentrations of 0.2, 0.4, 0.6 % w/w were used to improve stability of milk-barberry juice drink. The effect of barberry juice content was also evaluated at concerterations of 40, 50 and 60%. In treatments, the parameters of viscosity, sedimentation and whey separation were determined after two-week storage. Based on the findings treatments containing 0.2 pectin, 0.4 pectin, 0.2 mixture of pectin- carboxymethyl cellulose, 0.2 carboxymethyl cellulose, 0.6 pectin and 0.4 mixture of pectin- carboxymethyl cellulose with 60%barberry juice, had the highest stability, respectively. After that, the optimal formulation was prepared and stored at refrigeratedor for 42 days and its physicochemical properties were investigated. The results showed that the effect of milk or barberry juice and pectin content were significant (p 0.05) on sedimentation and whey separation. In all treatments the amount of anthocyanin, phenolic compounds and antioxidant capacity increased over storage. The treatment containing 60% barberry juice/10% milk, 30% water and 0.2 pectin was selected as the best product due to the lowest sedimentation and whey separation. The results revealed that the that production of milk-barberry juice drink by the low sedimantation and whey separation could be feasible using pectin, cmc and their mixture, respectively. Keywords: Barberry juice, Hydrocolloids, Sedimentation, Skim Milk, Stability
