A Study on Cooking of Agar-Agar

Decomposition of Sucrose and Agar-Agar in Kingyokuto

Abstract

This study has been done in order to examine the reason why the gel of Kingyokuto (the ratio of the contents of water, agar-agar and sugar was 100 : 2 : 100) becomes soft when the final temperature of heating process employed in the preparation of Kingyokuto exceeds more than 106 ± 1 °C and becomes more soft and sticky at 108 °C.
The value of pH fell down and the amount of reducing sugar increased as the final temperature of preparation process of Kingyokuto increased.
At 108 °C of final temperature of making Kingyokuto, sucrose and agar-agar contained in it decomposed. Glucose and fructose were produced from sucrose, and galactose from agar-agar, and during these degradation process, Kingyokuto became sticky.