THERMAL PROPERTIES OF SKIPJACK TUNA (KATSUWONUS PELAMIS

Abstract

Differential Scanning Calorimetry (DSC) was used to obtain specific heat, heat of fusion, and protein denaturation temperatures of raw skipjack tuna. Thermal conductivity values of raw skipjack tuna over a range of temperatures were determined by the line heat source probe method. Statistical analysis showed that there was no significant difference between the specific heat of loin meat (3.536 kJ/kg K), red meat (3.505 kJ/kg K), and viscera (2.263 kJ/kg K). There were significant differences between the backbone and loin meat, backbone and red meat, and backbone and viscera on specific heat values. The protein denaturation temperature of loin meat was higher than that of red meat. There was no significant difference between thermal conductivity of raw loin meat (0.57 W/m K) and viscera (0.56 W/m K). In general, thermal conductivity increased with temperature.

ACKNOWLEDGMENTS

The authors acknowledge the financial support of Star-Kist Seafood Inc., the United States Department of Agriculture National Needs Fellowship Program, and North Carolina SeaGrant. In addition, the authors wish to thank Ms. Penny Amato for her assistance with the DSC equipment and valuable discussion and Ms. Heather Stewart for her help with the line source heat probe.