Effect of roasted bambara groundnut (voandzeia subterranea) fortification on quality and acceptability of biscuits

Abstract

Biscuits were produced from refined wheat flour and roasted Bambara Groundnut (BGN) flour (140°C for 20 min) at ratio: 100:0, 80:20, 70:30, 60:40 and 50:50 respectively. The physical, chemical and organoleptic properties and acceptability of the biscuits were evaluated. The BGN fortified biscuits contained high quantities of crude protein (11.42-13.96%), total fat (14.30- 15.46%) and carbohydrate (64.85- 74.04%). The moisture content (3.42-3.74%) and the caloric value (451.94-454.38 kcal/100 gm) were similar in all the blends, while crude ash (0.56-2.13%) significantly (p<0.05) differed from each other. No significant difference (p>0.05) was observed between weight, thickness and spread ratio of the 100:0 wheat (control) and BGN fortified biscuits. However, there were significant differences (p<0.0.5) between the control and the fortified biscuits in breaking strength with the 100:0 ratio wheat flour biscuit having the higher value of 1.41. Sample with 50:50 ratio roasted BGN flour was significantly (p<0.05) darker in color than the control (100:0 wheat flour biscuit) and those fortified with 80:20 and 70:30 BGN flour. Sensory evaluation result indicates that all the fortified biscuits had high sensory ratings for the attributes evaluated. There were no significant (p>0.05) differences between biscuits with 80:20, 70:30 and 60:40 BGN flour and the control sample in crust color, crust surface characteristics and taste. Although, biscuits with ratio 50:50 BGN flour had lower mean scores in crumb color, texture and taste, they were generally acceptable to the panelist. In all, biscuits with up to 70:30 wheat flour/roasted BGN flour ratio blend compared favorably well with the control in all the evaluated quality attributes.