Influence of pasteurization in the goat milk sanitary quality

In this paper, the effect of pasteurization conditions on variation of total plate count and coliforms with raw goat milk and during its storage process was studied.Raw goat milk with different pollution levels were treated in conditions of 63℃ /30min, 72℃ /30s and 85℃ /15s.The change of total plate count and coliforms in these goat milk samples was extremely different ( p < 0.05) .With three groups of heat treatment conditions ( 63℃ /30min, 72℃ /30s and 85℃ /15s) , efficiency of microbial disinfection with raw goat milk was increased and efficiency of pasteurization with different polluting milk samples was reduced. For slightly and moderately contaminated milk samples after pasteurization stored at 5℃ /7d, their total plate count and coliforms did not change significantly ( p > 0.05) and did not exceed the pasteurized milk indicators in GB19645- 2010. For heavily contaminated milk samples which was stored for 7d at 5℃ after pasteurization, its total plate count and coliforms had significantly exceeded pasteurized milk indicators in GB19645-2010.Therefore, contamination of raw goat milk by microorganisms should be avoided during the production, storage and transportation processes. In order to improve the quality and shelf life of pasteurized goat milk, pasteurization conditions should be chosen as 63℃ /30min and storage temperature and time should be controlled with in 5℃ /7d.