Studies on the Optimization and Stability of Low-Fat Biscuit Using Carbohydrate-Based Fat Replacers

The objective of this study was to optimize and develop low-fat soft dough biscuits using carbohydrate-based fat replacers (combinations of polydextrose and guar gum). Central composite rotatable design was utilized to optimize the levels of sugar, composite fat (fat, polydextrose, and guar gum), ammonium bicarbonate, and water. The parameters measured were spread ratio, hardness, stress-strain ratio, and sensory properties. Composite fat and sugar were found to be important determinants of biscuit hardness. The principal effect of fat substitutes on biscuits' attributes was crisper texture but with higher brittleness. The level of water had a significant effect on spread ratio (p < 0.1), hardness (p < 0.1), and stress-strain ratio (p < 0.05). It was also observed that by varying the level of ammonium bicarbonate in the formulation from 0.5 to 2.5 g/100 g flour, the dimensions and texture of the biscuits were affected. The optimum ingredient levels on 100 g flour basis were found to be sugar 24 g, fat 10.5 g, polydextrose 24.2 g, guar gum 0.3 g, ammonium bicarbonate 2 g, and water 24 mL. It was found from the storage study that low-fat biscuit with 70% fat replacement was more oxidative stable than the control sample.