EFFECTS OF GUAR GUM AND MICROCRYSTALLINE CELLULOSE ON SENSORY AND THERMAL-PROPERTIES OF A HIGH-FAT MODEL FOOD SYSTEM

Descriptive sensory analysis, time-intensity (Tl) profiling and differ ential scanning calorimetry (DSC) were used to study the textural and thermal properties of a confectionary-like model food system consistin g of cocoa butter, sucrose and an aromatic flavorant. Varying amounts of microcrystalline cellulose (MCC) and guar gum were substituted for cocoa butter at levels ranging for 5% to 20% (by weight), alone and in combination. Descriptive analysis of the following attributed was con ducted: aroma, sweetness, total flavor, hardness, fracturability, adhe siveness, cohesiveness, amount of particles, particle size, smoothness /lumpiness, viscosity of the melted mass, melt rate, mouth drying, res idual amount of particles and mouthcoating. Added fat substitution dec reased sweetness, flavor and the rate of melting. Increases were seen in viscosity, perceived amount of particles, hardness, adhesiveness, m outhcoating and mouth drying. These changes were concentration depende nt and were more pronounced for guar than for MCC. Tl changes in sweet ness, melting and overall flavor paralleled the descriptive panel resu lts, with the largest effects observed in the 20%/20% mixture of guar gum and MCC. Melting enthalpies determined using DSC suggested a lower ed degree of crystallinity or differences in the polymorphic form of c ocoa butter in samples where fat was partially replaced with MCC or a mixture of MCC and guar. Sensory results from two panels, one in Helsi nki and one in Ithaca, NY were in most cases consistent with one anoth er. However, the Helsinki panel reported more pronounced sensory chang es. A simple cocoa butter system may be suitable for studying the text ural properties of proposed fat replacers in high-fat systems, utilizi ng descriptive sensory methodology.