Comparison of Traditional Thermocouples and Data Loggers for Simplified Temperature Monitoring Using Shellstock Oysters as a Model

Temperature control is an important aspect of food safety, and thermocouples have long been used for temperature monitoring. Nonetheless, thermocouples are not ideal for all products, particularly those of irregular size or those subjected to multiple handling steps throughout the farm-to-fork continuum. Newer electronic time-temperature recording devices are smaller, portable, and less prone to slippage. However, their accuracy, in comparison to that of traditional thermocouples, has yet to be validated. The purpose of this study was to compare traditional thermocouples and button data loggers with respect to their ability to record the temperature of shellstock oysters accurately during normal commercial storage. Commercial burlap bags of oysters were obtained and the temperature of individual oyster specimens was monitored internally and externally by use of T-type thermocouples and button data loggers. Specimens with thermocouples or button data loggers were placed side by side at different locations in the commercial burlap bags (top, middle, and bottom) to achieve representative cooling profiles based on product location. No statistically significant differences (P ≤ 0.02) in oyster cooling profiles were observed when thermocouple data were compared to button data logger data, irrespective of location in the commercial sacks (top, middle, and bottom) or temperature monitor location (internal vs. external). The results support the use of button data loggers as a practical and relatively inexpensive alternative for monitoring the temperature of oysters and perhaps other food products as they pass through the farm-to-fork continuum. [PUBLICATION ABSTRACT]