Abstract
Konjac mannan (KM) was gelatinized under several conditions, and the amount of acetyl group released by saponification during the induction period was determined. The amount was almost constant regardless of the reaction temperature, though the length of induction period decreased with an increasing temperature. The amount increased with the decrease in concentration of KM. Acetyl groups of KM were released completely at a concentration of about 0.5% of KM (the minimum concentration at which the gel can be formed). The amount increased with the increase in concentration of hydroxy ion in the reaction mixture. The variation profile of the degree of deacetylation with the concentration of hydroxy ion, however, was almost independent of the gelatinizer used. These findings confirmed the previously proposed conclusion that the deacetylation is indispensable for the gelation of KM as an induced reaction.
