摘要：The chemical and microbiological properties of Sudanese white soft cheese made by direct acidification technique were investigated. Three kinds of acidulant, namely lemon, orange and grapefruit juices were used to assess some quantitative and qualitative properties of white soft cheese. The parameters evaluated included yield of cheese, physico chemical composition and microbiological analyses. Cheese made by the use of lemon juice recorded the highest yield (18.5%), but values of 16.0 and 14.8% were obtained for orange and grapefruit juices, respectively. Both kinds of acidulants and storage period imparted negative effects by causing highest loss of weight (28.35%), using lemon juice; lowest (25.79%) in case of grapefruit. The loss of weight (27.03%) accounted for orange juice occurred at an intermediate position. Storage period significantly (p < 0.05) caused loss of weight that showed a trend of gradual increase until the end of the storage period, being the lowest (26.40%) after 15 days and highest (38.23%) after 60 days. The total solids recorded 53.32, 51.70 and 49.48%, for lemon, orange and grapefruit juices, respectively. Similarly, the storage period caused significant (p < 0.05) and consistent increase as the storage period progressed. The protein content indicated significant amount being 22.91, 22.51 and 22.10%; for lemon, orange and grapefruit and interrupted by decrease after 45 days of storage, before that a steady increase was attained. Significant increase in the fat content occurred at highest level (23.82%) when lemon juice was used but 22.10 and 20.08% were recorded for orange and grapefruit. The significantly enhanced fat concentration occurred from 19.38% at the beginning to 23.77% once the time elapsed after 60 days. The orange and grapefruit juices had similar leftover ash content lower than that obtained from lemon. The ash content increased with time until the end of the storage period. The highest pH-value (3.74) was recorded by adding grapefruit juice; other values got less 3.48 and 3.28 for orange and lemon, respectively. The storage period has given the highest pH-value (5.20) at the beginning and lowest (2.73) at the end. The total bacterial count decreased during storage of the three types of cheese, while the coliform, yeast and mould and Staphylococcus aureus recorded nil in all cheese samples during storage.
