Effects of the glass transition temperature on the shaving characteristics of Katsuobushi (boiled and dried bonito)

Abstract

This study assessed the effect of different temperatures on the product yield of flakes derived from shaving commercial Katsuobushi (boiled and dried bonito). The Katsuobushi was shaved using a household Katsuobushi-plane. The chosen temperature was lower than the glass transition temperature (glass state), and higher than the glass transition temperature (rubber state). Also, the load and energy associated with shaving each Katsuobushi was measured and used to compare Katsuobushi processing characteristics at the glass state and rubber state. The results showed that the product yield in the rubber state was consistently higher than for the glass state. The shaving load of rubber state Katsuobushi was lower than that associated with the glass state. The rubber state Katsuobushi was shaved with a shaving load of between eighty-five and ninety percent that of the glass state. The shaving energy for the rubber state Katsuobushi was less than that required for the glass state. Regarding specific shaving energy, which is the shaving energy necessary to get 1 g of Katsuobushi flake, the energy exerted for the rubber state Katsuobushi was less than that of the glass state. The rubber state Katsuobushi was shaved using only twenty-five to forty-six percent of the energy needed for the glass state. From these results, it was shown that rubber state Katsuobushi could be shaved more efficiently than glass state Katsuobushi. This indicates the potential for laborsaving and boosting material yield in shaving Katsuobushi on a commercial scale.