Effect of Dehydrated Nystose Addition on the Reduction of Water Activity

Abstract

Dehydrated nystose was prepared by thermal dehydration of nystose trihydrate, recrystallized from a commercially available syrup of fructooligosaccharides. Dehydrated nystose was found to have the ability to absorb moisture and the ability to maintain water activity (Aw) at a low level during its rehydration. These characteristics remained evident until an 8% (w/w) increase in weight had occurred, corresponding to the restoration of three molecules of crystallization water. As an application of these characteristics, we found that by addition of dehydrated nystose to sucrose powder the Aw is reduced to an appropriate value and the survival of lyophilized Bifidobacterium in the mixture is thereby maintained.