In all samples, the pH decreased from 4.5 to approximately 4.0 over the 28 day storage period (Table 2). pH reduction was slightly more in 1% and 2% lentil-supplemented samples in comparison with other samples. the higher the buffering capacity of yogurt, the lower the pH changes due to the changes in acid content of the food system. Data from this study, however, disagree with these observations since the control had the smallest drop in pH (Table 2).