Physicochemical and microbiological evaluation of yoghurt sold in Addis Ababa, Ethiopia

Increase in demand for yoghurt in Addis Ababa, in recent times has led to proliferation of different kinds of commercially produced (branded) yoghurt in line with the traditional (unbranded) one in the market. However, limited or no available data for the quality of gradually increasing different kinds of commercially produced (branded) yoghurt in line with the traditional (unbranded) one in the market. It was therefore vital to evaluate the physicochemical property and microbial quality of yoghurt sold in Addis Ababa in order to determine its quality and perhaps safeguard the health and wellbeing of the numerous people consuming yoghurt products. A total of 40 yoghurt samples consisted of 20 traditionally (unbranded) and 20 commercially produced (branded) were analysis for physicochemical property (pH, moisture, ash, fat, Total Solid (TS) and Solid Not Fat (SNF)) and microbial quality (Coliform Count (CC) and Yeast and Mould Count (YMC) were performed using TEMPO system whereas; Total Viable Count (TVC) was performed according to standard culture method). In the traditionally produced (unbranded) yogurt samples, the fat content was 4.44%, pH 3.99, TS content 10.12%, SNF content 7.18%, moisture content 89.88%, and ash content 0.53%. For the commercially produced (branded) yogurt samples, the fat content was 5.02%, pH 3.88, TS content 10.66%, SNF content 8.10%, moisture content 89.29%, and ash content 0.62%. The TVC in traditionally (unbranded) and commercially produced (branded) yoghurt samples was found to be 10.72 and 10.35 log10 cfu/mL, respectively. In terms of coliform counts (CC), 20%, 55%, and 25% of the traditionally produced yogurt samples had counts of < 10 cfu/mL, 10 to < 4.9 × 104 cfu/mL, and > 4.9 × 104 cfu/mL, respectively. For the commercially produced yogurt samples, 40%, 35%, and 25% fell within these same ranges. The overall mean coliform counts were 3.72 log₁₀ cfu/mL for traditionally produced yogurt samples and 2.81 log₁₀ cfu/mL for commercially produced yogurt samples; however, the difference was not statistically significant (P > 0.05). Similarly, for yeast and mold counts (YMC), 0%, 35%, and 65% of traditionally produced yogurt samples had counts of < 100 cfu/mL, 100—< 4.9 × 104 cfu/mL, and > 4.9 × 104 cfu/mL, respectively. In commercially produced yogurt, 30%, 50%, and 20% of samples fell within these same ranges. The overall mean YMC was 4.48 log₁₀ cfu/mL for traditionally produced yogurt samples and 3.92 log₁₀ cfu/mL for commercially produced yogurt samples, but this difference was also not statistically significant (P > 0.05). Based on the findings of this study, it is crucial to implement measures to improve the quality of yogurt in Addis Ababa to ensure consumer safety and product consistency.