The aim of this study was to prepare a bio-fermented milk product (Rayeb milk) with high nutritional and health benefits. Five various samples of Rayeb milk were manufactured as follow: T1 from cow milk, T2 from quinoa milk, T3 from cow and quinoa milk mixture (50%:50%), T4 from cow and quinoa milk mixture (75%:25%) and T5 from cow and quinoa milk mixture (25%:75%). ABT-5 culture was used as starter culture. The results showed that mixing of quinoa milk with cow milk stimulated starter bacteria during fermentation period. Rayeb contained quinoa milk had higher acidity and total protein/DM and lower moisture and Fat/DM values than those of cow milk Rayeb. Values of L* and b* slightly decreased whereas a* values slightly increased in Rayeb produced using quinoa and cow milk mixtures. The addition of quinoa milk to cow milk led to reduction in serum separation and syneresis levels. Apparent viscosity, yield stress and consistency coefficient values increased while plastic viscosity and flow behavior index values lowered in quinoa milk Rayeb. On the basis of the obtained results, it can be concluded that Rayeb milk made with 25 or 50% quinoa milk have better rheological characteristics than that of control Rayeb.

Ayran is a salted drinkable fermented milk food which consumed in many countries around the world. In this study, some chemical parameters were determined to evaluate the healthy properties of ayran prepared using various commercial probiotic cultures. Four treatments of ayran were made from cow’s milk and using classic yogurt culture (L. delbrueckii subsp. bulgaricus and Streptococcus thermophilus) [T1], ABT-5 culture (L. acidophilus, Bifidobacterium and S. thermophilus) [T2], exopolysaccharide producing culture (EPS-producing, L. delbrueckii subsp. bulgaricus and S. thermophilus) [T3], and EPS-producing culture + Bifidobacterium animalis subsp. lactis BB12 (mixture culture) [T4]. Treatment 1 had the highest acidity, acetaldehyde, and diacetyl values. Using probiotic [T2] or mixture cultures [T4] reduced saturated fatty acids by 1.97% and increased monounsaturated and polyunsaturated fatty acids of ayran by 4.94 and 5.72%, respectively. Also, the levels of oleic acid (omega-9), linoleic acid (omega-6), and α-linolenic acid (omega-3) increased in ayran produced using probiotic or mixture cultures. Sample T4 was highly richer in the value of antioxidant activity (27.62%) and folic acid (0.1566 mg/100 g) whereas possessed the lowest cholesterol amount (8.983 mg/100 g). Mixture culture (EPS-producing culture + Bifidobacterium animalis subsp. lactis BB12) is a good starter to improve the healthy and nutritional characteristics of bio-ayran.