Performance of coiled tube ultraviolet reactors to inactivate Escherichia coli W1485 and Bacillus cereus endospores in raw cow milk and commercially processed skimmed cow milk

► Inactivation of bacteria increased with Reynolds number of milk flow. ► Higher inactivation of bacteria in smaller diameter coiled tube reactor. ► Inactivation of Escherichia coli was higher for skimmed milk. ► Bacillus cereus endospores showed more resistant to UV dose than the E. coli W 1485 cells ► E. coli in skimmed milk was inactivated by more than 5 − log10 CFU/ml.