Yogurt is defined as a coagulated milk product obtained from the fermentation of lactose into lactic acid. Drinking yogurt (laban) was prepared from buffalo milk, cow milk, and a 50:50 blend (cow + buffalo milks) by adding 0.5% carboxymethyl cellulose to each of the 3 milk treatments. Samples were then refrigerated for 7, 14, and 21 d before determination of physical, microbial, and sensory parameters. Yogurt prepared from buffalo milk had higher fat and protein contents, and better taste, aroma, and overall consumer acceptability compared with laban prepared from cow milk or mixed milk. During storage, protein and total solids contents remained unchanged, whereas milk fat, color, appearance, taste, smell, texture, and overall acceptability of laban decreased in the different treatment groups. The acidity of laban increased with storage time. Bacteria, including coliforms, were not found in any treatment group during storage. In conclusion, overall acceptability of laban prepared from buffalo milk was higher than that made from cow milk or mixed milk, but increased storage time reduced the quality of laban prepared from cow, buffalo, or mixed milk.

Y_ij = each observation on j^th animal due to i^th treatment

The present study analyses the effect of storage time and varying fat levels in fermented laban milk samples obtained from different sources through physicochemical, sensory and microbiological attributes. The milk samples were divided into three groups (T1 = Buffalo Milk, T2 = Cow Milk, T3 = Mixed Milk) with replication. Viscosity, acidity and syneresis of all three laban milk samples increased, whereas pH decreased significantly (P ≤ .05) across storage days. The viscosity, protein and total solids (TS) were significantly (P ≤ .05) decreased in all Laban milk samples with a 3.5% fat level compared to a 1.5% fat level at the 21st day of the storage period. The colour and appearance scores were unaffected for the T1 group but decreased with increased fat levels for T2 and T3 groups. The Total Plate Count tended to decrease with a 3.5% fat level in all three laban milk samples. However, days of storage had a non-significant effect. Buffalo laban milk seems best in terms of viscosity, protein, TS, taste and aroma. Furthermore, these attributes are affected by days of storage and fat level. The fermented laban prepared from mixed milk (T3) showed results at par with that from buffalo milk. Hence, considering the economical aspect, mixed milk laban at a fat level of 3.5% is highly recommended.