Abstract

This study aimed to produce drinking yogurt using a lactic acid bacteria starter (Streptococcus
thermophilus and Lactobacillus bulgaricus) with different concentrations of aqueous aromatic
medicinal plant extracts garlic: )0.2%, 0.5% and 0.8%) and mint: )1%, 2.5% and 4%) . The treatments
were stored up to 21 days at 4 ± 1 ° C . The physicochemical properties were studied, which included
the measurement of (pH, total acidity, and viscosity) and microbiological examinations represented
by counting the (starter bacteria, coliform, Staphylococcus aureus, as well as yeasts and molds) and
sensory characteristics were measured after manufacturing on the first day , 7, 14 and 21 days of
storage. The results showed that there were no significant differences in pH values immediately after
manufacturing for all treatments. As for the percentage of total acidity (TTA), it was close to
immediately after manufacturing for all the different drinking yogurt treatments, while during storage,
a clear increase in their values was observed for all transactions. As for the viscosity values,
significant differences were found in their values immediately after manufacturing and during cold
storage and for all treatments. The results showed that the addition of aqueous extracts to the drinking
yogurt did not affect the numbers of starter bacteria and their activity throughout the storage period
compared to the control sample. Also, the results showed that the superiority of concentrations (2.5%)
for mint and (0.2%) for garlic in the sensory evaluation of the characteristics of taste, flavor, texture
and general acceptance