Effect of Heat Source and Storage Period on the Quality of Goat and Sheep Milk

This investigation was conducted to study the effect of heat treatment on the microbial quality of goat and sheep milk. Milk chemical composition and samples were collected from different farms in Shambat, Khartoum State. Raw goat and sheep milks were heated using charcoal, gas and microwave at ºC and stored for 10 days. The chemical 499 ºC for 12 min, then cooled to composition and microbiological characteristics were determined at day 1, 3, 7 and 10. The results showed that goat milk treated by charcoal had higher protein, lactose and SNF contents, then the milk treated with microwave had higher fat and TS contents. The acidity was higher in milk treated with gas, and no significant difference were found in ash content and pH. Sheep milk treated with charcoal had higher values for all chemical components except for lactose and acidity which were higher in milk treated with microwave. The storage period significantly affected all chemical components of goat milk except for the acidity which was not affected. Sheep milk was significantly affected by the storage period except for protein and ash contents. Total bacterial and lactobacilli counts were significantly higher in goat and sheep milks treated with charcoal and gas. During the storage period, total bacterial and lactobacilli counts significantly increased towards the end. The identification of bacteria of the genus level revealed that Staphylococcus and Bacillus were found in goat milk, while Streptococcus, Enterococcus, Staphylococcus and Bacillus were found in sheep milk during storag