Effect of citric acid fortification on the properties of tiger nut flour

Abstract

The effect of citric acid fortification on the properties of tiger nut flavor was evaluated. Flour was obtained from tiger nut and fortified with citric acid after which proximate and antinutrient compositions of the native and fortified tiger nut flour were evaluated using standard method of analysis. Doughnut was produced with fortified flour after which, sensory evaluation, microbial analysis and shelflife was compared with that of unfortified flour (positive control) and Wheat flour (negative control). Results showed that there were significant differences (P<0.05) in the proximate, anti-nutrient and sensory evaluations of the fortified flour and that of the control. The ash and carbohydrate contents of the fortified flour (5.51 ± 0.1 and 67.52 ± 0.031%, respectively) were significantly higher (P<0.05) than the control (1.60 ± 0.1 and 44.36 ± 0.011%, respectively). Protein contents of the control (5.50 ± 0.0%) was significantly higher than that of the fortified flour (4.20 ± 0.00%). Phytate, oxalate and tannin contents of the fortified flour samples (0.667 ± 0.54, 1.8008 ± 0.01, 0.220 ± 0.11%, respectively) were significantly higher than the control samples (0.845 ± 0.28, 11.399 ± 0.42 and 0.117 ± 0.31%, respectively). Cyanide contents of all the flour samples were not significantly different from each other. Organoleptic score revealed that the taste, texture and appearance of doughnut made with fortified flour was better than the controls, hence doughnut made with fortified flour was the most acceptable and preferred. No bacterial growth was recorded in all the doughnut samples however, the shelflife of donuts prepared with fortified flour was higher than (6 days) that of unfortified (4 days) and wheat flour (3 days). Therefore, fortified tiger nut flour, may replace the conventional wheat flour in bakery and confectionery owing to its nutritional value and longer shelflife.