Effects of incorporation of integral raw materials and dietary fibre on the selected nutritional and functional properties of biscuits

With the aim to develop nutritionally and functionally improved biscuits, standard wheat flour based recipe was supplemented with inulin (Raftilin) (10.5%) in combination with one of the following raw materials: soy flour, amaranth, carob (24.5%), apple fibre or oat fibre (16.5%). Various nutritional parameters such as proteins, fat, ash, carbohydrates total minerals, protein digestibility and energy value were determined in modified biscuits. Dietary fibre content, polyphenolic content and bioavailability and antioxidative activity were also assessed in the view of estimating the functionality of investigated samples. In order to evaluate the impact of technological procedure (baking) on analysed parameters, all experiments were conducted in dough samples as well. Supplementation with soy flour resulted in significant increase (p < 0.05) in protein content and digestibility (from 10.04 to 14.49 mg/100 g and from 68.9% to 81.5%, respectively). The increase of total dietary fibre content in relation to the reference sample ranged from 30.9% (sample with amaranth) to 130.6% (sample enriched with oat fibre). Best results regarding total phenolic content and antioxidative activity were achieved by incorporation of carob and apple fibre into the reference sample. Supplementation with inulin resulted in significant decrease of the total energy value of modified biscuits (from 445 to 412 kcal/100 g dry matter).