Influence of conching temperature and some bulk sweeteners on physical and rheological properties of prebiotic milk chocolate containing inulin.

摘要

Changes in food consumption habits and the developments set forth in the area of health and nutrition also change consumer expectations and demands. Sugar-free foodstuffs and products that have prebiotic activity are among the primary features of such expectations and demands. In the present study, the effects of substituting fine sugar with isomalt and maltitol in milk chocolate samples that contain inulin (9.0% w/w), which is a substance with prebiotic activity, and the use of varying conching temperatures (CT) (50, 55 and 60 degrees C) in the sample preparation process on their physical (colour, hardness, water activity) and rheological properties were examined. Rheological data were obtained using the Herschel-Bulkley model which showed the best fitting for predicting rheology. It was determined that all properties included within the scope of the study are affected by the use of different bulk sweeteners or varying CT (P<0.01). While colour properties, such as brightness (L*), hue angle (h degrees ), water activity (aw) and rate index properties varied in a narrow range, it was determined that the yield stress and viscosity properties, which are among the important quality parameters of chocolate and can have determining effects on sensory properties, manifest variations within a broad range, depending on the CT and the bulk sweeteners used. It was concluded that maltitol is a more suitable fine sugar substitute in milk chocolates containing inulin.