engleski

Textural properties of model systems of hydrocolloids and sugars

Texture is one of very important food quality properties. Different additives have influence on aroma and colour of fruit products, but their influence on texture should not be neglected. Hydrocolloids and sugars are additives that are very often used in preparation and formulation of fruit products. The aim of this study was to prepare model systems of hydrocolloids (guar gum or xanthan ; in amount of 0.6 %) and sugars (sucrose or trehalose ; in amount of 30, 40 or 50%) in order to investigate influence of different sugars and their amount on textural properties of selected hydrocolloids. Textural parameters that were selected for comparison of model systems were firmness, consistency, cohesiveness and index of viscosity. Xanthan systems without sugar addition had higher values of firmness (13.324 g) and consistency (115.68 g) than guar gum systems. Both systems had the same value of cohesiveness and index of viscosity. Addition of both sugars in different amount caused change of textural parameters. With increase of sugars amount increase of all textural parameters occurred. With addition of sugars, firmness of both hydrocolloid systems increased. In the case of guar gum there was no difference between addition of 30% of sucrose or trehalose, while with addition of 40 and 50% of sugar significant difference between sugars were obtained. Addition of trehalose had higher impact on guar gum firmness, and the higher values of those systems were observed. In the case of xanthan, addition of sucrose (all amounts) caused higher increase of firmness than addition of trehalose. The same tendency of sugars influence was observed in the case of consistency. There was no difference in cohesiveness and index of viscosity when 30% of sugars were added to guar gum systems. When 40 and 50% of trehalose were added, guar gum systems had significantly higher values of cohesiveness and index of viscosity. In the case of xanthan, sugar amount did not cause difference in cohesiveness and index of viscosity. Specific molecular interactions between sugars and hydrocolloids appear to have a significant contribution to textural parameters. Even thought, sucrose and trehalose are chemical isomers, it is obvious that interactions between those sugars and hydrocolloids, as well as sugar amount had high impact on textural parameters of model systems hydrocolloids and sugars.

model systems, hydrocolloids, sugars, textural properties

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