Freezing and Drying Conditions for Forming the Characteristic Inner Structure and Sensory Properties of shimi-mochi

Abstract

  shimi-mochi is a preserved food in the Tohoku area of Japan. The main materials used for shimi-mochi are glutinous rice and non-glutinous rice powder. shimi-mochi is repeatedly frozen and thawed in natural cold air to dry. It is soaked in water and cooked to eat, making it tender and easily broken. We made artificial shimi-mochi in this study by only using those main materials. The effect of the freezing and drying conditions on the characteristic inner structure and sensory properties of artificial shimi-mochi were investigated. It was possible to make artificial shimi-mochi by freezing and drying at －5℃ for 18 hours and at 3℃ for 6 hours, repeating this cycle for 28 days. Artificial shimi-mochi produced in this way had many vacant spaces similar to the traditional product, although it absorbed water in a shorter time than the traditional product. After absorbing water, artificial shimi-mochi retained its shape and, after cooking, retained its softness and stickiness for a significant time. Artificial shimi-mochi had the characteristic inner structure and sensory properties of the traditional product. Although the visual appearance was similar, the inner structure of artificial shimi-mochi produced under other conditions was completely broken after absorbing water. This result revealed that subtle differences in the process of freezing and drying affected the success or failure of producing artificial shimi-mochi.