Effects of sprouting duration on the nutrient, functional, and phytochemical properties of tiger nut flour, and the sensory properties of bread made thereof.

Abstract

The influence of sprouting on tiger nut's (TN) nutritional, functional, and phytochemical quality was examined, and the flour used for bread making to evaluate the feasibility as a functional ingredient. TN was sprouted and sampled at 3 days intervals for 12 days, dried and milled into flour and analyzed. Subsequently, 25% of wheat flour (WF) was replaced with the 9 days-sprouted TN flour for bread. Sprouting for 9 days increased the protein content from 9.19±0.04 to 9.79±0.15g/100g dry matter (DM), fiber from 6.75±0.16 to 9.27±0.44g/100g DM, and ash from 2.34±0.10 to 2.70±0.06g/100g DM but decreased fat content from 26.10±0.18 to 23.18±0.43g/100g DM and soluble sugar from 33.13±1.25 to 23.75±1.44°Bx. We observed increases in the polyphenols (94.16±6.43-214.23±6.98mg GAE/100g) and ascorbic acid (26.66±0.17-65.13±0.19mg AE/100g) and decreases in the cyanogenic glycosides (273.79±0.37-231.54±3.53mg/100g) and oxalates (19.04±1.14-5.65±0.93mg/100g) contents. Sprouting decreased the particle size and increased the water retention and swelling power of TN flour. WF bread was described as stretchy, sweet, and creamy, whereas sprouted TN bread was brown, nutty, and wheat-like. Consumer acceptance for the sprouted TN bread was comparable to WF bread, showing the possible application in bread making. PRACTICAL APPLICATION: The outcome of the study could help to exploit the nutri-functional and phytochemical benefits of sprouted TN in the baking industry for producing acceptable products. This would enhance the utility of TN for food in regions where TNs grows.