Production and Quality Evaluation of Acha-tigernut Composite Flour and Biscuits

Abstract

The research is aimed at adding value to acha based biscuits using less known and underutilized crops such as tigernuts. The objective of the study was to add value to acha based biscuits Tiger(brown) seeds were sorted, washed and oven dried(450C for 12hrs), milled(Attrition Mill) and sieved.Acha grains were washed, destoned, dried(450C), milled and sieved. The tigernut flour was substituted at  2, 4, 6, 8 and 10% into acha flour to produce tigernut-acha composite flour and 100% acha as the control sample, used for production of biscuits with the addition of other ingredients (baking fat, baking powder, salt and water). Powdered date palm was used instead of sucrose (sugar). Functional and pasting properties of the composite flour and chemical, physical and sensory properties of composite biscuits were determined. Bulk density, oil absorption capacity, swelling power, swelling index, and foaming capacity increased from 0.772 to 0.91, 0.64 to 0.68, 235 to 370%, 3 to 9, 5.56 to 10.53 and 5.566 to 10.105, respectively with an increase in the added tigernut flour. Peak, tough. Break down, final viscosity and set back values decreased from 1322 to-925, 1049 to 803,270 to 122, 2677 to 2158 and 1628 to 1356RVA, respectively, with an increase in the added tigernut flour. The spread ratio and break strength increased (5.2-5.9) and decreased (0.515 to 0.315kg), respectively with an increase in the added tigernut flour. The protein, ash, moisture and carbohydrate contents of the composite biscuits decreased from 6.04 to 5.22, 2.12 to 1.96, 9.42 to 8.81 and 68.84 to 66.46% respectively, while the fat, crude fibre and energy content increased from 13.58 to -17.57, 2.06 to 4.01% and 421.72 to 444.77cal/g, respectively, with increase in  added tigernut flour. The average means scores for taste, aroma, colour, and general acceptability decreased, while an increase were observed for other assessed attributes. Addition of tigernut flour  improved the fibre, fat and energy content as well as the crispness and texture   of acha-tigernut- biscuit .