Heat control - basic principle

Control through heat No growth - time beyond TDT for Bacillus subtilis No growth - Thermal death time (TDT) at 100 degree Celsius for Bacillus subtilis is 40 minutes Significantly reduced growth after 20 minutes of heat treatment Further reduction in growth after 10 minutes of heat treatment Growth is slightly reduced as a result of 5 minutes of heat Heavy bacterial growth - indicates growth of live culture

Staph - heat control No growth - time beyond TDT for S. aureus No growth - Thermal death time (TDT) at 100 degree Celsius for S. aureus is 1 minute Heavy bacterial growth - indicates growth of live culture