Production and Evaluation of Biscuits from African Yam Bean (Sphenostylis stenocarpa) and Wheat (Triticum aestivum) Flours.

Abstract

Composite biscuits were made by supplementing wheat flour (WF) with African yam bean flour (AYBF) after the seeds have been sorted, sun dried, roasted, some soaked, dehulled, winnowed, milled, and sieved into fine flour using a sieve size of 0.4mm and used at various ratios. (WF/AYBF 100:0, 75:25, 50:50,25:75,0:100). The 100% wheat flour biscuit served as the control. Sensory evaluation of the biscuits were determined and subjected to Statistical Analysis of Variance (ANOVA) and means were separated using the Generalized Linear Model (GLM) of SAS system. The means were separated using Fischer LSD and judged significantly different at 95% confidence level (P<0.05). The biscuit samples had proximate composition ranging from 6.35 – 11.45% Moisture content, 0.48 to 4.21% Ash, 0.88 to 2.28% Crude fibre, 12.75 to 22.0% Protein, 1.43 to 2.34% Crude fat, 63.30 to 73.01% Carbohydrate. The functional properties of the biscuit samples ranges from 0.53 to 0.71g/ml Bulk density, 14.70 to 20.40% Water absorption capacity, 0.60 to 11.81% Oil absorption capacity, 5.52 to 43.21% Foam capacity, 64.00 to 190.00 seconds Wettability, 6.01 to 15.37% Gelation capacity and 15.10 to 52.10% Emulsion capacity. The anti-nutritional composition of the biscuit samples ranges from 106.40 to 191.20mg/100g Trypsin inhibitor, 1.69 to 74.40mg/100g Phytic acid and 0.08 to 0.45mg/100g Tannins. Sensory evaluation results showed that all the biscuit samples had high rating for all evaluated attributes. The 75:25%and 50:50% of AYBF supplementation compared favourably with control (100% WF). Biscuits from other substitution levels were generally acceptable as they were neither liked nor disliked by the panelists.

Key words: Composite biscuits, African Yam Bean Flour, Wheat flour ,evaluation.