In the present study, the effect of five numbers of commercial dahi starter cultures, the changes in pH and tritratable acidity during curdling of milk while dahi making on fate of inoculated pathogens viz.,Escherichia coli AB1157 and Salmonella typhimurium were assessed. Commercial dahi starter cultures namely, NCDC 154, 159, 161, 166 and 91 has been procured from National Collection of Dairy Culture, National Dairy Research Institute, Karnal and utilized for preparing dahi. Dahi prepared by back slopping using culture from students’ boarding house, College of Food and Dairy Technology, Chennai has been kept as control. | Changes in physico-chemical characteristics of milk during dahi preparation on fate of inoculated bacterial pathogens