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An Investigation of the Most Appropriate Z-Value to be used in Calculating ‘Equivalent Cooks’ for Beef Burgers in Food Business Establishments

Thursday, 19 April 2018

The safety of beef burgers is dependent on sufficient cooking to ensure the destruction of pathogens.

This report is of interest to food businesses that  cook burgers. It is recommended that beef burgers are cooked to a minimum core temperature of 70 °C for at least two minutes or to a core temperature of no less than 75 °C. However, in recent years, catering establishments have started offering beef burgers prepared at temperatures below a core temperature of 70 °C.

It is possible to achieve an ‘equivalent cook’ (equivalent to 70 °C for two minutes) at lower temperatures if the heat is applied for longer times. However, calculating an ‘equivalent cook’ requires the use of a mathematical formula that uses the z-values of the target organism, which is usually Listeria monocytogenes, as it is one of the most thermal-resistant foodborne non-spore-forming bacterial pathogens.

The objective of this report was to determine which z-value was more appropriate and would offer the greatest food safety protection. It provides a guide to this for food businesses.

Report cover


Scientific Reports |