Microbiological and Physicochemical Characteristics of Plain Set Yoghurt Manufactured by Traditional Plants in Khartoum State, Sudan

Abstract

Aims: This study was conducted to evaluate the microbiological and physicochemical characteristics of plain yoghurt manufactured by traditional plants in Khartoum State.  Methodology: Fifty samples of plain set yoghurt were collected from traditional plants in Khartoum State (Khartoum, Omdurman and Khartoum North towns) at day 1 of manufacture in sterile plastic containers and transported in ice box (4ºC) to the laboratory for microbiological and physicochemical examination. Results: The results showed that the area of sampling significantly affected the microbiological quality of yoghurt except Staphylococcus aureus. Samples from Khartoum had high count of total viable bacteria (TVB), coliform bacteria, lactobacilli and yeasts and moulds counts (Log 10 9.76±0.129, Log10 5.95±0.0166, Log 10 4.92±1.284 and Log 10 4.87±0.067 cfu/g, respectively). TVB and coliform bacteria counts were high in samples from plant B (Log 10 9.83±0.117 and Log 10 6.02±0.207 cfu/g, respectively), while S. aureus count was high in samples from plant E (Log 10 4.29±0.039) and lactobacilli and yeasts and moulds counts were high in samples from plant D (Log 10 5.25±1.777 and Log 10 4.89±0.046 cfu/g respectively). Fat, total solids (TS) and ash contents were high in samples from Omdurman (4.00%±0.946, 12.29%±1.351 and 0.76%±0.039, respectively), while protein content was high in samples from Khartoum (3.63%±0.371) and pH was high in samples from Khartoum North (5.50±0.397). Fat, TS and ash content were high in samples from plant E (4.82%±0.451, 13.48%±0.473 and 0.77%±0.030, respectively), while protein content was high in samples from plant B (3.80±0.251) and pH was high in samples from plant C (5.49±0.397).  Conclusion: Yoghurt from traditional plants was contaminated with microorganisms that may causes diseases to human, so legislations should be adopted to prohibit such plants.