Influence of furcellaran and safflower oil concentration on the properties of model emulgel systems.

ABSTRACT

The aim of this study was to investigate the effect of varying concentrations of furcellaran (FUR) and safflower (Carthamus Tinctorius) oil on the functional properties of emulgels as potential carriers of bioactive substances. The textural, mechanical, thermal and structural properties of twenty different formulations were characterised. The pH stability and zeta-potential of the emulgels was also examined. It was found clear correlation between gelling agent and oil fraction content and investigated properties. The hardness, strength, thermal stability expressed as melting point of the investigated systems increased with increasing concentration of the furcellaran and decreasing proportion of safflower oil, which indicated a significant weakening of the structure as a result of the addition of the oil fraction. Stored under refrigeration, emulgels appeared to be relatively stable showing a slight decrease in pH values after 7 days. Swelling ratio (SW) of emulgels increased with increasing both, polysaccharide and oil content, in emulgels. Based on the microstructure analyses, it can also be concluded that only part of the added safflower oil chemically bound to the functional groups of the polysaccharide, while the vast majority of it was only physically immobilized in the furcellaran matrix. Colour of furcellaran - safflower oil emulsion gels depended largely on the amount of oil fraction. The presented research demonstrating the wide spectrum of functional properties of polysaccharide-oil systems is a first step to developing a carrier composition for lipophilic compounds at further stages of research.