ACCURACY, PRECISION AND RESPONSE TIME OF CONSUMER FORK, REMOTE, DIGITAL PROBE AND DISPOSABLE INDICATOR THERMOMETERS FOR COOKED GROUND BEEF PATTIES AND CHICKEN BREASTS*

ABSTRACT

Nine different commercially available instant-read consumer thermometers (forks, remotes, digital probe and disposable color change indicators) were tested for accuracy and precision compared with a calibrated thermocouple in 80 and 90% lean ground beef patties and boneless and bone-in chicken breasts cooked on gas grills, electric griddles and baked in consumer ovens. All models registered less than 42% of the products as cooked at the recommended insertion time except for one indicator model which registered greater than 50% of the products as cooked in five meat product/cooking method combinations. Average thermometer readings deviated from the thermocouple by as much as 64F. Increasing insertion time increased percentage of product registering as cooked and decreased the temperature difference. Measurement repeatability (precision) was high within and between individual thermometers of the same model. These results indicate that consumers using these thermometers would cook meat products to higher temperatures than necessary to destroy harmful microorganisms.

PRACTICAL APPLICATIONS

Consumers are urged to use thermometers when cooking meat products. Consumer fork, remote, digital probe and disposable indicator thermometers are aggressively marketed for their convenience to the consumer. There is relatively little scientific information regarding the accuracy and response time for these types of thermometers. The results of this study conclude that these thermometers register temperatures much lower than the thermocouple temperatures. As a result, consumers will cook meat products to a higher end point temperature, which provides extra food safety but in some cases may cause detrimental quality changes.