Enhancing the structure of reduced sugar jam with insoluble dietary fibers addition

The effect of addition date fruit insoluble fibers (DF) on the reduced sugar jam physiochemical properties at different concentrations (0, 3, 6 and 9% w/w) was evaluated. The jam was evaluated for the composition, water activity, color, syneresis, rheological and textural profiles. The results showed DF acts as a filler that reinforces the jam's gel structure. DF incorporation enhanced jam gel structure, indicated by the increase in gel strength from 0.012 MPa (0% DF) to ∼0.052 MPa (9% DF) and gel elastic properties. Initially, the jam hardness increased to 166 g (3% DF), however reduced hardness (93%) was observed at 9% DF, due to the DF water retention. Similar results exhibited for the jam adhesiveness. DF addition reduced the amount of expelled water from jam gel network, thus lowering the syneresis from 36 to 19%. DF addition imparted the jam color to be a unique red brownish tone due to a combination of natural red-brown pigments present in the date fruit fiber itself. Additionally, DF incorporation reduced the jam total sugar (18 to 13 mg/g) and reducing sugars (12 to 10 mg/g), suggesting the absorption of sugars by DF, which is consistent with °Brix value reduction (20 to 10). This study indicates the potential of DF in structuring the reduced sugar jam network, reducing the sugars and the utilisation of DF as a value-added ingredient in food systems.