Microbiological Quality of Cows' Milk Butter Processed in Khartoum State, Sudan

Aims: This investigation was carried out to study the microbiological quality of butter produced in Khartoum State, Sudan.

Methodology: Butter was manufactured traditionally by farmers in Khartoum north (T1) and Omdurman (T2), in addition to butter manufactured commercially in a dairy plant (T3) and butter manufactured by researchers in the laboratory (T4). Microbiological characteristics were evaluated at 1, 15, 30, 45 and 60- day intervals for samples stored at 5.0±1.0°C, and at 1, 7, 14, 21 and 28- day intervals for samples stored at 25±2.0°C.

Results: The results showed that total viable bacteria count (TVBC) significantly increased from the beginning of storage period to the end in butter of all treatments, with the increase being remarkable for samples stored at 25°C. Coliform bacteria increased to a lesser extent compared to TVBC, with the increase being crucial in samples stored at 25°C. The storage temperature significantly affected the counts of yeasts and moulds, Pseudomonas aeruginosa, proteolytic and lipolytic bacteria, however, the difference in the count of lipolytic bacteria between the two temperatures was not of importance.

Conclusion: In this study, the microbiological quality of butter is mainly affected by the method of butter manufacture and storage conditions during the storage period.