LASER-BASED POSITIONING AND DRILLING SYSTEM FOR PLACING A TEMPERATURE SENSOR INTO A FOOD SAMPLE

A device for positioning a temperature sensor into the geometric center of a beef patty was developed. The device consisted of a vertical digital stage fitted with a sample holder, a horizontal stage, a laser displacement sensor with a digital voltmeter, and a reversible (rotation) variable speed drill. Thirty fresh and frozen quarter-pound patties were drilled and fitted with a temperature sensor at the geometric center. The sensor tip location was then determined using an x-ray imaging system. Mean axial positioning accuracy was 92% and 90% for fresh and frozen patties, respectively. Mean radial accuracy was consistently 96% to 99.8%. Number of patties with accuracy of 85% or higher was 25 (out of 30) each for fresh (four patties with 100% accuracy) and frozen (eight patties with 100% accuracy). The device developed from this study provides a research tool for reliable insertion of temperature sensor into beef patty thus enhancing capacity to monitor cooking process and to evaluate product safety. Further improvement on accuracy of locating a sensor at the geometric center could be achieved by pre-selecting frozen patties having flat surfaces.