Abstract
Spirulina has been used for many years as human food because of its high protein content and nutritional value. The plenty of biologically important compounds in the algae, provide new opportunity for producing functional dairy products The main purpose of this study was to determine the effect of the powdered Spirulina platensis on the titratable acidity and pH of probiotic Doogh samples containing Mentha piperita during the refrigerated storage. In this research, Doogh samples were enriched with different concentrations of Mentha piperita (0.5 and 1%) and Spirulina platensis (0, 0.3, 0.5 and 0.8%). The treatments were stored at 4 °c for 21 days. pH and acidity of samples were measured at regular (7-day) intervals. The results showed that an increase in the concentration of Spirulina platensis induced a significant increase in the titratable acidity of probiotic Doogh during cold storage. However, the pH decreased slowly with the increasing alga content. There was no significant difference in pH and titratable acidity between samples with various concentrations of powdered Mentha piperita during storage time.
