Optimization of a process for high fibre and high protein biscuit

Biscuits are popular and convenient food products due to their ready to eat nature. Biscuits were prepared from sorghum and whole wheat flour with the addition of spirulina (Spirulina platensis) powder to produce high fibre and high protein biscuit. Levels of ingredients in biscuits such as spirulina powder, sorghum flour and guar gum were optimized using response surface methodology (RSM) for its sensory, textural and antioxidant attributes. Sensory attributes as colour intensity (R2=0.89, P<0.0001), flavor (R2=0.98, P<0.0001), sweetness (R2=0.97, P<0.0001), graininess (R2=0.99, P<0.0001), and crispiness (R2=0.94, P<0.0001), textural attributes as hardness (R2=0.95, P<0.0001) and fracturability (R2=0.96, P<0.0001), antioxidant activity as DPPH inhibition (R2=0.87, P<0.0001) and antioxidant activity as ABTS inhibition (R2=0.98, P<0.0001) were significantly related to processing parameters of biscuit. Rheological characteristics (TPA and extensograph) of biscuit dough were measured. Studies indicated that amongst all the processing parameters, the composition of spirulina powder and sorghum flour was found to have significant effect on the responses.