Temperature and time for safe cooking of meat

All meat, especially when there is inaccuracy regarding origin and handling, can be contaminated with pathogenic microorganisms. Therefore, it is essential to follow some guidelines when cooking meat safely. There are circumstances in which the preparation varies according to the customer's request, rare meat, for example, is preferred by the majority of barbecue lovers, and this is a major challenge when we try to ensure the absence of harmful elements to the human body. In these cases, strict control of the origin and care of the product is necessary, as the final preparation will most likely not be able to eliminate the contamination that is already embedded in the meat.

FSIS (Food Safety and Inspection Service) made this reference available to the North American industry. This is a table with the temperatures and times for maintaining exposure of certain meats to these temperatures to ensure that contamination by salmonella (reference pathogen) is satisfactorily reduced.

Slow cooking below 54.4ºC is strongly inadvisable as it is at a level that favors the proliferation of a wide range of pathogenic organisms. To produce food at this temperature, it would be necessary to study in depth the type of meat, possible forms of preservation and the specific microorganisms that can proliferate under these conditions.

Below is a table of temperatures and times for the safe preparation of meat. Temperatures refer to measurements inside the meat.

                                                  
        Degrees Degrees 6.5-log10         7-log10
        Fahrenheit Celsius Elimination Elimination 130 54.4 112 min. 121 min. 131 55.0 89 min. 97 min. 132 55.6 71 min. 77 min. 133 56.1 56 min. 62 min. 134 56.7 45 min. 47 min. 135 57.2 36 min. 37 min. 136 57.8 28 min. 32 min. 137 58.4 23 min. 24 min. 138 58.9 18 min. 19 min. 139 59.5 15 min. 15 min. 140 60.0 12 min. 12 min. 141 60.6 9 min. 10 min. 142 61.1 8 min. 8 min. 143 61.7 6 min. 6 min. 144 62.2 5 min. 5 min. 145 62.8 4 min. 4 min. 146 63.3 169 sec. 182 sec. 147 63.9 134 sec. 144 sec. 148 64.4 107 sec. 115 sec. 149 65.0 85 sec. 91 sec. 150 65.6 67 sec. 72 sec. 151 66.1 54 sec. 58 sec. 152 66.7 43 sec. 46 sec. 153 67.2 34 sec. 37 sec. 154 67.8 27 sec. 29 sec. 155 68.3 22 sec. 23 sec. 156 68.9 17 sec. 19 sec. 157 69.4 14 sec. 15 sec. 158 70.0 0 sec.*         0 sec.*

         159 70.6 0 sec.*         0 sec.*

         160 71.1 0 sec *         0 sec.* 

*The necessary elimination is reached instantly upon reaching this internal temperature.

FSIS arranged the measurement of the elimination of pathogenic microorganisms in “x-decimal”. A “1-decimal” of elimination represents 90% of elimination in the number of organisms. A “5-decimal” elimination reduces organisms by a factor of 10⁵ or 100,000. For more details about the formula, visit http://www.fsis.usda.gov/OPPDE/rdad/FRPubs/95-033F.htm and read the part about lethality.

It must be taken into account that meat exposed to contamination for a long time may contain large amounts of toxins deposited by microorganisms. These toxins are not considered in this reference. Many toxins are denatured during the cooking process, but some are extremely resistant to heat, therefore, even knowing that the elimination of microorganisms itself can be practically total, it must be taken into account that there may still be toxins in the meat. In other words, it is not safe to eat spoiled meat simply by eliminating the resident microorganisms!

http://www.fsis.usda.gov/OPPDE/rdad/FRPubs/95-033F/95-033F_Appendix%20A.htm