Evaluation of the Hygienic Quality of Market Milk of Khartoum State (Sudan)

Abstract

This study was carried out between August 2003 and March 2004. One hundred and twenty milk samples were collected from supermarkets in Khartoum State. Sixty milk samples were collected during summer and other 60 during winter from the same supermarkets. The milk samples were examined for microbial quality that include total bacterial count, spore forming bacteria count, coliform count. Enumeration, isolation and identification of E. colt, S. ctureus, Salmonella spp. and the presence of Brucella as detected by milk ring test were also estimated. The criteria used for identification of the isolates were reaction to Gram's stain, morphological appearance, cultural characteristics and biochemical tests. Similarly phosphatase test was done. The present study revealed that high average total bacterial count (5.63 x109±2.87x10' cfu mL-1) was found for the raw milk samples. Moreover, during summer the total bacterial count of milk (1.04x101°±4.01 x10' cfu rnL-1) was higher than during winter (9 x108±2.51 x109 cfu mL-1). Staphylococcus aureus was detected in 46.7% of the milk samples with mean count of 4.9 x104±1.29 x 106 cfu mL-1. During summer the mean count was 7.44 x105±1.66x10 6 cfu mL-1, which was higher than the count during winter (1.61 x 105±2.3x 105 cfu mL-1). Escherichia colt were detected in 2.5% of the milk samples with a mean of 6.0 x105±7.94 x105 cfu mL-1 and coliforms bacteria were detected in 82.5% with a mean of 3.32x 10 6±1.43 x107 cfu mL-1. Also during summer the mean was 5.15 x106±2 x107 cfu mL-1, which was higher than during winter (1.45x 106±3x 106 cfu rnL-1). Spore forming bacteria were detected in 32.5% of the milk samples with a mean of 4.81 x106±1.4 x107 cfu mL-1. Also during summer the mean was 7.15 x 106±1.79x 107 cfu rriL-1, was higher than during winter (1.45x 106±3 x106 cfu rnL-1). There was no Salmonella spp. in any of the milk samples collected during the present study, while milk ring test for Brucella showed that 44.1% of the milk samples were positive for Brucella. Moreover 54.4% of which were detected during winter and 45.61% were found during summer. Also during this study 44.17% of the milk samples were positive to phosphtase test. All the milk samples (100%) were found to be negative to the presence of formalin. Conclusions and recommendations for improvement of hygienic quality of marketed milk in Khartoum State were suggested. Sanitary standards should be established in this country so as to control milk production and marketing. Further studies should be done to evaluate safe and good supply of consumed milk.