Study on the glass transition of Katsuobushi (boiled and dried bonito fish stick) by differential scanning calorimetry and dynamic mechanical analysis

Abstract

The glass transition state of Katsuobushi (boiled and smoke-dried bonito) was studied by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). DSC and DMA data proved Katsuobushi as a glassy material. The glass transition temperature (Tg) measured by DSC was about 33°C in 14.8% moisture. In general, moisture content of Katsuobushi on the market is approximately 12-15% and the Tg value of Katsuobushi containing such moisture was approximately 10-30°C and this was within the room temperature range. Furthermore, the Tg of Katsuobushi showed strong dependence on moisture content, and the Tg value varied from 11 to 165°C with moisture levels from 18.04 to 0%.