Freezing Preservation of “Tokoroten”

Abstract

It was reported in the previous paper1) that the lyophilization is a preferable method for the preservation of “tokoroten”, gelidium jelly, as the lyophilized product save, on reconstitution, a jelly having similar flavour and elasticity to those of the original “tokoroten”. In this study, freezing preservation of it was attempted. “Tokoroien” cut into 1.4 cm cubes was frown by three different methods, vacuum freezing, air blast freezing (3m/sec) at -30°C and still air freezing at -30°C, and stored at -25°, -15° and — 5°C for 3 months. At a definite storage interval, the samples were dissolved in boiling water. The resulting solutions were condensed to the original concentration and gelatinized. The jellies thus obtained were examined on tbeir qualities, such as colour, flavour, texture, palatability. jelly strength and compressive strain, to compared with those of the original one. Immediately after freezing, reconstitution of all samples was nearly perfect. The jellies prepared from the stored samples showed only slight discolouration and off-flavour. The storage temperature and period did not affect the qualities appreciably. It may be concluded from these results that “tokoroten” can be preserved frozen at least for 3 months at a temperature as high as —5°C without any unfavourable change of quality, and that the frozen “tokoroten” can be reconstituted almost perfectly if the process of thawing in boiling water is introduced. © 1968, The Japanese Society of Fisheries Science. All rights reserved.