Pasteurized Milk in Khartoum State (Sudan)

Abstract

The present study was conducted to investigate the effects of storage conditions on the hygienic quality and shelf life of pasteurized milk produced by one of the dairy factory in Khartoum State. Moreover investigations on the possible sources and causes of contamination of pasteurized milk were also done. Three areas (Sixty samples) were selected in Khartoum North according to fluctuations in electrical supply, permanent supply (stand by generator) and immediate marketing. Other twenty samples were stored in the laboratory (Faculty of Animal Production) at 7°C. These samples were examined to determine the total number of bacteria, coliform bacterial counts, Escherichia coli counts and psychrophic bacterial counts. Also the presence of Salmonella spp. and Proteus spp., in pasteurized milk were reported. The counts of total bacteria were found to range between 6.5x105 and <6.5x1014, psychrophilic bacteria were between 6.5 x107 to <6.5x 10', coliform counts revealed 6.5x 1012 to 6.5 x10' and E. coli were between 0 and <6.5x 1011. The results showed that storage conditions have effects on bacterial counts (P <0.001). The results also showed that pasteurized milk samples were free from Salmonella whereas Proteus spp. were found in 20 % of the examined samples and E. coli was isolated from 90 % of the samples. The survey in the factory revealed 100%, 80% and 80% positive isolation of E. coli from raw milk samples and pasteurized milk before and after filling, respectively. While filling machine after used, rinsed water and tap water showed 100% 100% and 0% for the presence of E. coli. The present study concluded that the pasteurized milk distributed in Khartoum State by the selected dairy factory is of low quality. Hence it was recommended that hygienic quality monitoring programs are urgently needed to ensure that quality milk are produced and consumed in the country.