Abstract The effect of using tiger nut flour to improve the functional properties of gluten-free biscuit was explored. Corn flour in the biscuit formulation was replaced at three levels, 10, 20, and 30% with tiger nut flour (TNF). Biscuit containing only corn flour was used as control. Prepared biscuits were analyzed for their proximate composition, physical properties, diameter, thickness, color, texture, and were subjected to measurements using differential scanning calorimetery (DSC) and scanning electron microscopy (SEM).
Incorporation of tiger nut flour resulted in a significant increase in fibre and ash contents and in a decrease in protein content. The spread ratio of the biscuits increased significantly by increasing TNF content, which is considered a desirable quality attribute. Tiger nut-containing biscuits exhibited lower total color difference ΔE value compared to the control sample.
Thermal characteristics of TNF-containing biscuits differed significantly (P≤0.05) from the control where TNF resulted in decreased onset gelatinization temperature (To) and peak temperature (Tp). Furthermore, enthalpies of control biscuits were significantly higher than of those containing TNF; that might be due to partial gelatinization since their enthalpies were smaller than in control biscuits.
Measurement of baked biscuits texture showed that hardness and resilience values decreased when TNF content in the biscuit formulation increased. Microscopic observation revealed that TNF-containing biscuits had the most uniform and homogeneous pore distributions. These attributes probably positively influenced the quality with better surface characteristics. The results of this study revealed that incorporating TNF at the ration of 20% resulted in biscuits of superior technological quality expressed in shape, cross section structure, hardness, and surface appearance