Quality Characteristics of Biscuits Produced from Composite Flour of Sweet Potato and Cashew Nut Flour Blends

Abstract

The research is aimed at adding value to sweet potato based biscuits using underutilized crops such as cashew nuts. The objective of the study was to add value to sweet potato based biscuits, the sweet potato was processed into flour; while the cashew nuts was unroasted cashew nuts were sorted to remove the stones, dirt’s and unwholesome cashew nuts, roasted, shelled, dried, peeled and processed into flour and sieved. The cashew nuts flour was substituted at 20, 30, 40 and 50% into sweet potato flour to produce sweet potato and cashew nuts composite flour were  used for the production of biscuits. Functional, proximate composition of the biscuits, physical and sensory properties of composite biscuits were determined. Significance difference (P<0.05) was observed Bulk density, water absorption capacity, oil absorption capacity, swelling capacity, emulsion activity, foaming stability and gelatinization temperature increased from 0.62 to 0.73 g/cm3, 1.31 to 1.81 g/g, 2.10 to 2.22 g/g, 6.42 to 7.18 ml, 59.71 to 60.51%, 6.19 to 6.43% and 68.20 to 72.10ºC, respectively with an increase in the addition of cashew nuts flour. The crude protein, crude fat, crude fibre and ash increase from 14.65 to 18.31%, 7.88 to 10.21%, 3.21 to 3.51% and 4.10 to 4.76% respectively; while the moisture and carbohydrate content of the biscuits decreased from 13.77 to 13.31% and 56.39 to 49.89%, respectively with increase in the addition of the cashew nuts flour. The physical properties of the composite biscuits such as the weight, thickness, diameter and spread ratio ranged from 16.09 to 17.45 g, 10.87 to 10.96 mm, 38.94 to 40.02 mm and 3.56 to 3.60 respectively. The average means scores for the appearance, crispness, taste, aroma and overall acceptability increase were observed. There was a significant difference (p<0.05) in the appearance, taste and aroma while there was no significant difference (p>0.05) in the crispness and overall acceptability.