Prevalence of Thermophiles and Mesophiles in Raw and UHT Milk

摘要

The objective of the study was to evaluate the contamination level of cow's raw milk and different brands of UHT milk in Baghdad local market for thermophilic and mesophilic bacteria. The numbers of colony counts in milk samples were determined by the culture method according to bacteriological standards methods. Investigations were carried out for seven weeks in college of veterinary dairy farms from March 2013 to May 2013. Six (29%) positive samples out of 21 samples were tested for thermophiles in raw milk while 36 (100%) milk samples of Ultra High Temperature (UHT) were positive for thermophiles. Twenty one (100%) of mesophiles in raw milk samples were positive while in UHT milk samples only 18 (50%) out of 36 were positive. Overall the means of mesophiles have more significant counts differences (p<0.05) than thermophiles in raw milk samples. In UHT brands indicated that the results revealed high numbers of thermophiles in Nada and KDD which indicated that these brands were low quality. Moreover the values of these brands have significant differences (p<0.05) comparing with the UHT milk brands Al-Maraee and Al-Safi. In the same time the UHT brands were shown high numbers of mesophiles in Nada and Al-Safi which indicated that these brands have significant differences (p<0.05) comparing with Al-Maraee and KDD. This study was concentrated on milk contamination occurred after milk producing as well as processing, transport and store of UHT.