activityThe presence of soybean during yogurt forma-tion increased (p < 0.05) the antioxidant activitiesin both cow and camel milk-yogurts (61.76 ± 3.3%and 53.16 ± 0.9% respectively) compared to respec-tive plain-yogurts (26.41 ± 07% and 15.44 ± 1.2%for plain-cow and -camel milk respectively; Fig. 5).Soybean–camel milk yogurt showed the highest antioxi-dant activity on day 7 of storage (67.59 ± 1.4%) followedby reduction (p > 0.05) to 61.56 ± 1.4% on day 21 ofstorage. The antioxidant activity of soybean–cow milkyogurt showed significant reduction during 21 days ofrefrigerated storage to 35.29 ± 1.0%. Phenolic contentis the most influential factor to antioxidant activity [44].Soybean has been previously reported to show antiox-idant activity properties associated to isoflavones andpolyphenolic compounds [45,46]. Additionally, milkprotein proteolysis [47] and organic acids production[48] as a result of microbial metabolic activity during fer-mentation and refrigerated storage could be other sourcesof antioxidant activities