Freezing method of straw mushroom (volvariella volvaceae) using dry ice

Abstract

The purpose of this study was to assess freezing method of straw mushroom (Volvariella volvaceae) using dry ice, which one of refrigerant with boiling point at -78.5°C. Freezing rate of using dry ice is faster than using freezer. Ratio of 1:2 of straw mushroom with dry ice, has freezing rate of 0.27°C/min and freezer has 0.05°C/min. Freezing method by dry ice influenced straw mushroom tissue after thawing. Histological of straw mushroom showed that the tissue loss of fluid, resulting shrinkage and cell attachment, and greater dehydration due to differences in humidity. From the results can be concluded that freezing method of straw mushroom using dry ice has slow freezing rate, but with the assumption that smaller ice crystals formed than using freezers, based on the time needs to exceed the critical freezing zone 0-(-3.9 )°C.