Best results in crumb hardness and specific volume were obtained using 1 Â 106 units/300 g rice flour. Given
the cost of the enzyme used in bread making, we suggest a thermoase level of 2 Â 105 units/300 g rice flour, because this level
yielded low crumb hardness and high bread volume. The experi-mental purchase price of the thermoase level was about 6 yen in 2012, but the industrial purchase price is expected to be much cheaper. This low cost is an advantage of thermoase compared with glutathione.