Microbiological Characteristics of Traditionally Fermented Milk (Roub) Manufactured and Sold in Khartoum State, Sudan

Aims: This study was conducted to evaluate the microbiological quality of roub collected from different areas in Khartoum State, Sudan during the storage period.

Methodology: Thirty roub samples were collected from Khartoum, Khartoum North and Omdurman areas in sterile polyethylene bags, preserved in sample containers in ice (4ºC) and transported to the laboratory for analysis. Microbiological [total viable bacteria (TVB), coliform bacteria, lactobacilli, yeasts and moulds] characteristics were determined at 1, 7, 14 and 20-day intervals.

Results: The results showed that all microorganisms tested (except coliform bacteria) were significantly (P<0.001) affected by the area from which samples were collected, with TVB being high in Omdurman (Log 6.35±1.027 cfu/gm), while lactobacilli (Log 7.75±0.775 cfu/gm) and yeasts and moulds (Log 7.49±0.685 cfu/gm) were high in Khartoum North, and coliform bacteria were high in Khartoum (Log 6.29±2.497 cfu/gm). The storage period significantly (P<0.001) affected all microorganisms tested. Coliform bacteria and lactobacilli were significantly (P<0.001) affected by the storage period in samples collected from Khartoum, while only coliform bacteria were significantly (P<0.001) affected in samples collected from Khartoum North. All microorganisms were significantly (P<0.001) affected by the storage period in samples collected from Omdurman except coliform bacteria which were not detected.

Conclusion: It is concluded that there was a significant variation in microbial contamination of the product collected from different areas in Khartoum State, as well as the storage period affecting the microbial count of the product.