Date juice addition to bio-yogurt: The effects on physicochemical and microbiological properties during storage, as well as blood parameters in vivo

This study aimed to investigate the impact of adding Zahdi date juice on the physicochemical characteristics and microbiological analysis of bio-yogurt with a probiotic starter (St. thermophilus, Lb. acidophilus, and B. longum) and haematological parameters in mice. The bio-yogurt was prepared by adding a 5% probiotic starter supplemented with date juice at 2, 5, and 10% (v/v). Hematological parameters: Mice (n = 30) were divided into five groups (Tc, T1, T2, T3, and T4) and treated with either a standard diet or a standard diet enriched with 3 ml/day of bio-yogurt containing 0, 2, 5, and 10% date juice for 30 days. The results showed that the addition of date juice increased the acidification rate, decreased pH values, and improved the syneresis of bio-yogurt. During the 21-day period, the viability of probiotic bacteria decreased, but a bio-yogurt sample containing 10% date juice had a higher number of probiotic bacteria than the other samples. The diet and body weight of the mice were affected by the daily administration of bio-yogurt or bio-yogurt with date juice. In addition, the groups treated with bio-yogurt, including date juice, typically had superior haematological parameters and better immunity levels than other groups (P ≤ 0.05). Compared with the control group, mice administered bio-yogurt containing date juice showed reduced total cholesterol and triglyceride levels. In conclusion, the addition of date juice to the bio-yogurt improved the physicochemical properties and increased the viability of probiotic bacteria as well as improving the blood parameters of experimental animals.