Beef's optimum internal cooking temperature as seen by consumers from different countries using survival analysis statistics

A total of 306 consumers from Argentina, Spain and the USA, segmented by age groups (young and middle-aged adults) and stated preference for degree of doneness (rare, medium, well-done) looked at pictures from the American Meat Science Association (AMSA) Color Guide and decided if these were under-cooked, ok or over-cooked. Survival analysis statistics were applied to the data to predict optimum internal cooking temperatures. These ±95% confidence intervals were: 75 ± 6.2 °C, 78 ± 4.3 °C and 82 ± 2.6 °C, for consumers stating a preference for rare, medium and well-done beef, respectively. Country of residence and age group had little influence on optimum temperatures. Relatively high optimum temperatures, and the fact that only 4% of the consumers found the "55 °C-very rare" and "60 °C-rare" pictures ok, suggests the necessity of revising the range of the AMSA Color Guide.