2007 Volume 11 Issue 1 Pages 13-23
The aim of this study was to clarify the usefulness of some composite systems with multiple gelling agents and to suggest a new type of gelled foods designed for people with swallowing and mastication difficulties. The goal of the composite system was to recreate gelatin-like texture with enhanced setting rate and higher thermal stability than gelatin.
Agar, deacylated gellan gum, psyllium seed gum, and gelatin were used as gelling agents. Physical properties of these gels or gelled foods with these gelling agents were investigated by dynamic viscoelasticity measurements under a small deformation and by puncture tests under a large deformation. Water-holding capacity was also determined by the quantification of syneresis.
Composite gels from agar and psyllium, or gellan and psyllium, exhibited similar physical properties to those of gelatin but with higher thermal stability represented by a smaller temperature dependence of the elasticities. Furthermore, these gels were proved to be stable against storage without generating any marked syneresis.
It is generally recognized that agar or deacylated gellan gum forms brittle gels with observable syneresis, leading to low ability to forrn bolus in the mouth. Gels from psyllium seed gum, on the other hand, have superior water-holding capacity, but the texture is highly elastic and adhesive. This means that each ingredient cannot be used alone as the base material in food products. Our study suggested that the combination of multiple ingredients is an approach to attaining our goal.
