Abstract
Miso paste mixed with stock is popular because of its convenience. However, phosphatase, an enzyme present in miso paste, promotes the decomposition of this type of stock. To inactivate this enzyme, it is therefore necessary to heat miso before stock is added. Unfortunately, heating degrades the color and flavors of fresh miso. Radio-Frequency (RF) heating was thus used to inactivate enzymes in packed miso paste, and enzyme inactivation (phosphatase and protease) by RF heating was subsequently compared to that by conventional heating. Our results showed that the phosphatase and protease in packed miso were completely inactivated by RF heating at 72°C, which is 12°C lower than that observed with conventional heating. Furthermore, the RF heating time was reduced to one-third that of conventional heating.
